Description of a Collection of Cephalopods

from the

Cretaceous Deposits of Dagestan

with a list of forms
of other classes and a stratigraphic outline.

by

P. Kazansky.

DESCRIPTION

of a collection of Cephalopods from the
Cretaceous deposits of Dagestan

with a list of species of the other classes and a stratigraphic sketch

by P. KASANSKY.

Tomsk.

Typo-lithography of the Siberian Printing Partnership, corner of Dvoryanskaya St. and Yamskoy Lane, own building.

1914.

I

Historical Sketch

The sketch offered here does not claim to be exhaustively complete. Its purpose is only to show the course of development of our present knowledge of the Cretaceous deposits of Dagestan.

The fact of the existence of Cretaceous deposits in Dagestan was noted as early as 1837 by Dubois de Montpéreux (“Lettre sur les principaux phénomènes géologiques du Caucase et de la Crimée, adressée à M. Élie de Beaumont,” in Bulletin de la Société géologique de France, I sér., vol. VIII). The contemporary ideas concerning the distribution of Cretaceous deposits in Dagestan are shown on the map by the same author in his Voyage autour du Caucase and on Murchison’s map (Geology of Russia in Europe).

The scientific world’s concrete acquaintance with the Cretaceous deposits of Dagestan began only with the classic works of Abich, which started in 1844. Of the numerous papers by this latter author, only three have substantial significance for our subject, and their contents must be set forth here.

The first of these papers appeared in 1851 under the title “Verzeichniss einer Sammlung von Versteinerungen von Daghestan mit Erläuterungen,” in Zeitschrift der Deutschen geologischen Gesellschaft, vol. III. This paper, the paleontological part of which belongs chiefly to L. von Buch, presents a list of a paleontological collection from Dagestan with a description of the localities of the fossils. There is no general sketch and, in general, no synthesis of the data in the paper. It is therefore very difficult to summarize its contents. One can only cite individual sections and lists of fossils from them. The paper gives forms from the following points:

1. Kalibegi. At the top lies limestone of the Cretaceous system; beneath it occur loose beds with concretions, containing Ammonites Martini d’Orb., Toxoceras, Buccinum, Pleurotomaria elegans, Thetis minor—Neocomian according to Abich; beneath these beds lie—

a gray clayey limestone occurs, gradually passing into a hard ferruginous shelly conglomerate.

1. Gergebil. Here Abich indicates only the nearly vertical upper Cretaceous beds with Ammonites Rhotomagensis, overlying the limestone.

2. Gavvidara. Upper Cretaceous deposits, expressed as fine-grained chalk with Belemnites, Inoceramus sulcatus, and Exogyra laciniata.

3. Between the aul and the fortification Kumukh, along the Kazikumukh Koisu River, gray sandstone-like beds are developed, alternating with slaty marls that pass downward into clayey shales. In the marls occur concretions with silicified wood, saurian teeth, Ammonites strangulatus d’Orb., Mytilus falcatus d’Orb., Mytilus sp. — Neocomian according to Abich. Below lies a hard, dark, slaty rock.

4. Kharikzila. Oolitic limestone with Avicula, Terebratula tamarindus Fitt., Terebratula faba Fitt., Terebratula nuciformis, corals, and Manon macrostoma.

5. At the pass through Kharikzila there are developed light-yellow and gray, slaty, sandstone-like beds with calcareous cement and geodes of gray limestone. Here were collected Cyprina rostrata Fitt., Trigonia alaeformis. Neocomian according to Abich.

6. Near Dushushi and Khoina, in a brown fine-grained sandstone, Ostrea disjuncta Abich was collected. At Khoina this sandstone becomes increasingly compact and passes into a dense gray limestone with Ostrea, an oolitic limestone with Terebratula nuciformis, and a dense splintery limestone with Terebratula biplicata.

7. In the valley of the Kazikumukh Koisu River, below, clayey sandstones with bituminous concretions are developed, containing Ammonites Milletianus d’Orb., Rostellaria macrostoma Fitt., Thetis minor d’Orb., Panopaea, Pholadomya, Astarte, Mytilus, Perna, Pinna, Exogyra, Ostrea, Arca. Abich sees among them partly Neocomian and partly Gault forms.

8. Around Akusha, the mountains are composed of limestone with Ammonites Mayorianus, Inoceramus sulcatus, Inoceramus latus — Gault according to Abich. In the valley of Akusha, at the top, hard Cretaceous limestones with Ananchytes are indicated; beneath them is a gray Pläner with Exogyra and Inoceramus; lower down occur loose, clayey marls, becoming more calcareous upward, with Aucella Caucasica Abich. Still lower, beneath loamy alluvium, loamy-sandy ...

lower beds with Ammonites, very large Lamellibranchiata, Perna Milletii Leym., Pinna Robinaldina d’Orb., Ostrea, Exogyra; still lower lies a bed representing a solid breccia of shells of Anomia laevigata Fitt., also containing Thetis major d’Orb. Still lower are visible loose clayey beds with concretions containing Perna Milletii, Thetis major, Anomia laevigata, Pinna Robinaldina, Rostellaria macrostoma, Belemnites. All the beds lying below the bed with Aucella Caucasica are regarded by Abich as Neocomian. Without a precise indication of the bed, Terebratula nuciformis is also cited from the Akusha valley.

1. On Turchi-Dagh Abich distinguishes, at the top, a dense and coarsely splintery limestone with Ostrea Milletiana d’Orb., Exogyra haliotidea Goldf., Terebratula nuciformis Sow. and Terebratula biplicata angusta; according to Abich this is Neocomian. Beneath it lie loose, more or less sandy beds with Pholadomya donacina Goldf., Perna Milletii. The geodes of Turchi-Dagh with Ammonites Deshayesii, Ammonites fissicostatus, Ammonites Milletianus, Ammonites Calypso, Ammonites Duvalianus, Ammonites infundibulum are not clearly determined stratigraphically, and to the forms encountered in them Abich assigns partly the age of the lower Gault, partly of the upper Neocomian. From the connection of the exposition one might suppose that these geodes occur below, but the indications of age attached to the fossils contradict such an assumption.

2. On Chunu-Dagh Abich distinguishes, at the top, light marls with geodes; below lie darker clayey and shaly marls interbedded with shaly calcareous beds. A subordinate position is occupied by loose clayey-sandy beds with geodes containing Belemnites subfusiformis d’Orb., Ammonites Hugardianus d’Orb., Turritella sexlineata Roem., Astarte formosa Fitt. Beneath these beds there again appear darkish calcareous interbeds passing into ferruginous sandstone. Between the limestone and the sandstone Nucula scapha d’Orb. was found, and in the sandstone Scalaria canaliculata d’Orb., Donax. Then there appear coaly shales with impressions of plants.

3. On Chalburg-Dagh Abich indicates only a red sandy limestone with Nerinea nobilis Goldf. and Terebratula.

4. On Shakh-Dagh there are distinguished upper dolomites with Ostrea carinata d’Orb., Astrea angulosa Goldf., and a lower stage with Terebratula nuciformis and Terebratula biplicata angusta.

1. In the Durangi gorge Abich found smooth Inoceramus and Pecten.

These data can only with difficulty be reduced to any kind of summary. From them it may be concluded that the Upper Cretaceous beds in Dagestan are represented by compact limestones with Ananchytes and by light-colored marls and limestones with Ostrea and Inoceramus. In addition, Abich distinguishes in the Lower Cretaceous the Gault and the Neocomian. Both stages are expressed by more or less loose marls, sandy and clayey rocks, often with concretions, and contain a rich fauna. Still older, apparently, are limestones with Terebratula nuciformis, tamarindus, biplicata, faba, and “corals.” The age of these limestones remains somewhat uncertain; judging from the note at Terebratula biplicata angusta, Abich is inclined to ascribe a Neocomian age to these limestones. The deposits with concretions have, in different cases, a somewhat different character. The greater part of them, apparently, should be placed between the Gault and the Neocomian.

A second article by Abich, important for our purpose, was published in 1858 under the title “Vergleichende Grundzüge der Geologie des Kaukasus, wie der Armenischen und Persischen Gebirge” in “Mémoires de l’Académie Impériale des Sciences de St-Pétersbourg”; 6. sér.; tome VII. In this article, relevant to our purpose is the section placed on pp. 476–478, dealing with the Cretaceous (and Jurassic?) deposits of Dagestan between Kumukh and Uluchra. In this section the following geological formations are distinguished from top to bottom (from younger to older).

K. Upper division of the Cretaceous formation above the Gault, with Ammonites Rhotomagensis, Inoceramus sulcatus, Exogyra laciniata, etc.

G. Gault, and upper green sand: thick loose beds with numerous well-preserved fossils (enormous ammonites)—45–60 m in thickness. Ash-gray limestones, resembling sandstones on the surface. A loose marl rich in lime, with spherical concretions. Clayey and sandy beds. The fauna contains: Ammonites Milletianus, Ammonites Deshayesii, Ammonites fissicostatus, Ammonites Martini, Ammonites Duvalianus, etc.

N. Compact white, sometimes oolitic dolomitic limestones; fauna: Terebratula nuciformis Sow., Terebratula biplicata angusta, Ostrea Milletiana d’Orb., Exogyra haliotidea d’Orb., etc.

k. Light-colored calcareous marls (Neocomian) with flat spherosideritic concretions, sometimes containing ammonites from the group Falciferi. Subordinate sandy-clayey beds.

contain, in bituminous clayey shales: Belemnites subfusiformis d’Orb., Ammonites Hugardianus d’Orb., Turritella sexlineata = Turritella difficilis d’Orb., Astarte formosa d’Orb., etc.

t. Gray sandstone-like marls and shaly sandstones of great thickness, with Neocomian fauna.

c. Dark, compact pelitic rocks with compact bituminous limestone concretions contain fragments of silicified wood, saurian teeth, Ammonites strangulatus, Mytilus falcatus d’Orb.

b. Dark-brown shaly-limestone beds with fragments of charred and silicified wood and with shells resembling Donax and Cyrena.

a. Dark marly shales of the upper division of the principal Dagestan clay-shale formation.

On p. 494 of the same article Abich, speaking of the Cretaceous deposits of Dagestan in general, refers only to his earlier article and supplements it by pointing out that on Shakh-Dag very probable representatives of the Caprotina zone occur in limestones similar to those which on Chalbuz-Dag contain Nerinea nobilis.

The third article by Abich, which should be set forth here, bears the title “Sur la structure et la géologie du Daghestan” and was printed in 1862 in Mémoires de l’Académie Impériale des Sciences de St.-Pétersbourg, VII série, tome IV, No. 10. Here, for the first time, a general section of the Cretaceous deposits of Dagestan is given (pp. 6–9). Beneath the Tertiary sandstones developed in the north of Dagestan there also lie Tertiary clays, sands, marls, and shales. Beneath these latter is situated a group of beds called by Abich the supra-Cretaceous. This latter is expressed above by variegated sandy and clayey marls without organic remains, and below by compact marly limestones passing into whitish and greenish limestones. In the marls are visible impressions of stems and, at times, leaves of aquatic plants. The Cretaceous deposits proper are subdivided by Abich into three stages.

The upper stage of the Cretaceous system represents a thick sequence of limestone and marly rocks. In its upper half there predominates true white chalk, with characteristic parallel bedding, with banks of black siliceous nodules and with irregular zones colored red by iron oxides. The prevailing types of this white chalk are chalk with large inocerami: Inoceramus Cuvieri, Cripsii, latus, and chalk with ananchites (Ananchytes ovata, corculum Goldf.).

The lower part of the stage consists, counting from top downward, of compact

of light-gray clayey limestone, of shaly black clayey or semicalcareous marls with impressions of plants and flattened shells of lamellibranchs, and, finally, of more or less clayey, very thin gray marly chalk.

The middle stage of the Cretaceous system is represented above by yellowish, sometimes somewhat ferruginous, thin sandstones, which along the Abikh correspond, petrographically and faunistically, to the upper green sandstone. They contain calcareous-siliceous concretions, sometimes arranged in regular beds.

Beneath these sandstones lie greenish-yellow and blackish sandstones of weak consistency, reaching an unusual thickness.

Beneath them are found delicate marly sandstones with nodules of siliceous limestone, filled with fossils.

A characteristic feature of all these beds is the presence in them of spherical concretions of hydraulic lime, containing numerous fossils characteristic of the Gault and the green sandstone. Enormous ammonites occur here.

The lower stage of the Cretaceous system is composed above of blackish, nodular clayey limestones in irregular banks, interbedded with earthy layers and greenish-gray clayey and sandy marls. These limestones contain Exogyra Couloni.

Beneath them lie considerable beds of grayish or bluish sandy limestone, passing into dense sandy marls and interbedded three times with very thick, formerly more or less crystalline, and in places oolitic, limestone with a mass of partly broken and abraded fossils.

At the bottom, finally, are yellowish, whitish-gray, and light-brown hard and compact limestones with a small quantity of fossils that are difficult to separate from the rock.

Thereafter, for almost 30 years, the study of the Cretaceous deposits of Dagestan underwent no significant additions. Only in 1889 did a short article by Sjögren appear: “Uebersicht der Geologie Daghestans und Terek-Gebietes,” printed in Jahrbuch der Kaiserlich-Königlichen Geologischen Reichsanstalt, Band XXXIX. This

the article is to a considerable degree merely a translation into a more modern language of Abich’s data, but it also contains in part new data.

The Dacian stage is represented, according to Sjögren, by Abich’s supra-Cretaceous group. It consists of marl-like limestones, several tuffaceous and chalk-like ones. In the absence of petrifactions, apart from characteristic impressions of plants or, perhaps, traces of animals, the age of the corresponding beds is determined only by their position above the Senonian deposits and by the imperceptible transition into the latter.

The Senonian stage reaches a thickness of 1000 meters. It is composed of massive white limestones, in which two horizons may be distinguished:

the upper, in which the limestones, sometimes showing platy separation, are interbedded with layers of calcareous marls; here are found: siliceous concretions, Belemnitella mucronata, Inoceramus Cripsii, Ananchytes ovata;

the lower, in which the limestones contain thick bands of red-brown and gray-green marls. Here only indeterminable ammonites have been found.

The Turonian and Cenomanian beds, according to Sjögren, are absent in Dagestan.

The Gault and Aptian sometimes reach 200 m in thickness and make it possible to distinguish two horizons:

the upper is represented by dark slaty argillaceous marls, interbedded with light-gray limestones;

the lower consists of yellowish, greenish, and black loams and marls with spherical concretions, containing excellently preserved, often enormous cephalopods and lamellibranchs; here occur: Hoplites fissicostatus, Hoplites Deshayesi, Acanthoceras Milletianum, and Inoceramus sulcatus.

The Neocomian is likewise subdivided into two horizons: the upper, whose thickness does not exceed 100 m, consists of dark calcareous sandstones and greenish sandy marls with earthy interbeds; characteristic of this horizon are thick banks with Ostrea and Exogyra Couloni.

The lower horizon, more than 200 m thick, consists of hard and compact yellowish or gray limestones, sometimes

oolitic, interbedded three times with dense sandy marls; here dolomites also occur. Fossils are rare and poorly preserved; in the dolomites there are species of Terebratula.

Beneath the Cretaceous deposits lie, not clearly separated from them, dolomites and limestones of the Jurassic system.

In 1895 there was printed in the “Materials for the Geology of the Caucasus”—2nd series, book 9, an article by N. Barbot-de-Marny entitled: “Report on the Investigation of the Mineral Resources and Geological Structure of Dagestan”; part I: northwestern Dagestan. This article is accompanied by a geological map on the five-verst scale and contains fairly detailed stratigraphic data on the Cretaceous deposits of the locality studied by the author. The author distinguishes the following horizons in the Cretaceous deposits, counting from top to bottom:

Senonian. Upper division.

Layered limestones of yellowish-gray color with Ananchytes ovata, Inoceramus Cripsi, Terebratula sp. Dense light-gray limestones with interbeds of greenish-gray calcareous marls with rare Terebratula.

Dense yellowish-gray limestones with Turrilites cf. Archiacianus d’Orb., Inoceramus Cripsi, Micraster coranguinum, Offaster sp., and in central Dagestan also with Belemnitella mucronata.

Dense yellowish-gray limestones with Hamites simplex, Scaphites sp., Turrilites polyplocus, Ammonites sp., Inoceramus Cripsi, Ostrea sp.

Snow-white limestones with Inoceramus Cripsi, Inoceramus regularis d’Orb., Inoceramus sp.

Senonian. Lower division.

Reddish-gray limestones with Inoceramus sp.

Bright-red limestones with interbeds of calcareous marls of brick-red color.

Violet-black limestones.

Violet-red limestones with interbeds of calcareous marls and black flint.

Thin-bedded white limestones with interbeds of black marls.

Thin-bedded limestones with interbeds of marls and black flint.

Turonian and Cenomanian. Greenish-gray and smoky-gray clayey limestones and calcareous marls, alternating

with yellowish-gray compact limestones. Fossils occur chiefly in the smoky-gray limestones: Belemnites sp., Inoceramus cuneiformis d’Orb., Inoceramus problematicus d’Orb., Inoceramus Brongniarti, Ostrea carinata.

Black clayey marls with interbeds of yellowish-white compact limestones.

Gault: Albian and Aptian stages.

Dark-gray shaly clayey marls.

Loose clayey yellowish-gray sandstones and sands with spherical concretions and marls subordinate to them.

Loose clayey greenish-gray glauconitic sandstones with Terebratula nuciformis, Terebratula depressa, Ostrea sp., Inoceramus concentricus, Aucella sp., Serpula sp., Hoplites Deshayesi. Black clayey marls and brown clayey sands with concretions of brown ironstone, with Acanthoceras Milletianum.

Neocomian: Urgonian stage.

Compact dark-brown clayey sandstones, alternating with dark-gray marls, containing concretions of brown ironstone. In the sandstones there are many Ostrea Couloni, Corbis corrugata, more rarely Ostrea Milletiana.

The same sandstones, but poor in fossils: Ostrea, Fucoides.

Lower Neocomian.

Greenish-gray and yellowish-gray glauconitic compact calcareous sandstones with Ostrea Milletiana and Ostrea sp.

Light-gray sandy marls.

Compact oolitic limestone of yellowish-gray color with Ostrea and Terebratula sp.

Light-gray sandy marls.

Yellowish-gray compact breccia-like limestones and calcareous sandstones. To these limestones probably belongs the author’s indication that they consist entirely of joints of Crinoidea, Bryozoa, fragments of Terebratula and Ostrea.

Light-gray sandy marls.

Lensen. Dolomite breccias with Diceras of the Jurassic system. The summary given represents the exposition of the author’s table on

pp. 245–246 of his article, with additions from the text (pp. 252–260). The text and the table are not free from mutual contradictions; where such contradictions occur I have preferred the indications of the text.

In 1897 N. I. Karakash’s master’s dissertation appeared, under the title “The Cretaceous Deposits of the Northern Slope of the Main Caucasus Range and Their Fauna.” As regards Dagestan, this work contains only literary data, the content of which has entered into my preceding account. It is worth noting only certain practical remarks by the author concerning the article by Barbot de Marny just discussed. N. I. Karakash finds Barbot de Marny’s paleontological characterization of the Turonian stage insufficient, pointing in particular to the absence of authors’ names after the names of species of Inoceramus and to the presence, in the Turonian of the article he criticizes, of the Cenomanian Ostrea carinata. Moreover, in the opinion of N. I. Karakash, Barbot de Marny’s Urgonian stage, faunistically, rather resembles the Lower Neocomian (pp. 138–139).

In 1899 Dim. Anthula published in Beiträge zur Paläontologie und Geologie Oesterreichs—Ungarns und des Orients the article “Ueber die Kreidefossilien des Kaukasus mit einem allgemeinen Ueberblick über die Entwicklung der Sedimentärbildungen des Kaukasus.” This article contains a description of the collections of Abich and Sjögren from the Cretaceous deposits of the Caucasus and a summary of all literary data known to the author, together with the results of the study of the indicated collections. By its character this article is fundamental for knowledge of the Cretaceous fauna of the Caucasus in general and of Dagestan in particular.

In stratigraphic respect the author relies entirely on Abich and Sjögren; therefore the chief interest of Anthula’s work consists in the determination of those forms which were collected in the localities described by Abich and Sjögren and which, up to that time, had either not been determined at all or had been determined on the basis of data that were too obsolete.

Concerning the supra-Cretaceous deposits, Anthula merely repeats Abich’s and Sjögren’s indications as to their composition of dense Cretaceous marls and tuff-like limestones with remains of wood and impressions of leaves.

The Cenomanian deposits consist of writing chalk and marly limestones with black siliceous concretions. From them the following forms are cited from various places in Dagestan.

From the valley of the Argun, in white marl:

1. Inoceramus Cripsii Mant.
2. Austinocrinus radiatus Anth.

From Shamkhal-Dag:

1. Prenaster carinatus Anth.
2. Holaster sp. ind aff. senonensis d’Orb.
3. Inflataster Abichi Anth.
4. Coraster Vilanovae Cotteau.
5. Ananchytes depressa Eichw.
6. Austinocrinus Erckerti Dames.

Between Boshuk and Meni, from light-gray argillaceous marl:

1. Micraster breviporus Ag.

From Gimry, from white marl:

1. Inoceramus Cripsii Mant.

From Gunib:

1. Coraster Vilanovae Cotteau.

In addition, with reference to Abich, the occurrence at Shakh-Dag is cited of:

1. Ananchytes ovata Lam.

Of the Turonian and Senomanian in Dagestan the author knows nothing.

As a result, for the Upper Cretaceous deposits the author combines the following section from top to bottom:

Danian stage:

white and gray limestones and marls with Coraster Vilanovae (Gunib), marls with Stegaster Caucasicus.

Senonian proper:

white limestones and marls with Inoceramus Cripsii and Austinocrinus Erckerti (Shamkhal-Dag).

Turonian ————

Senomanian ————

The Gault of Dagestan is regarded by the author chiefly also on the basis of the data of Abich and Sjögren. From this stage Anthula lists:

from the valley of Akushi.

1. Parahoplites Bigoureti Seunes sp. from green sandstone (Middle Barremian and Aptian).
2. Desmoceras (Puzosia) Mayorianum d’Orb. sp. Gault sandstone, according to Abich.
3. Aporrhais cf. Orbignyana Pict. et Roux.
4. Panopaea acutisulcata Desh. green glauconitic sandstones above the bed with Panopaea plicata.
5. Thetis caucasica Eichw. according to Eichwald.

1. Thetis major Sow. from beds with Anomia, according to Abich; in gray calcareous sandstone; in light-gray sandstone with Rhynch. Deluci.

2. Thetis minor Sow. from the geodes in sandstone, according to Abich; specimens were in Anthula’s work.

3. Trigonia aliformis Park. geodes in glauconitic sandstone (M. b. agte).

4. Trigonia Abichi Anth. in yellowish sandstone.

5. Cucullaea obesa Pict. et Roux in gray marly limestone.

6. Cucullaea glabra Park. in gray marly limestone.

7. Aucella Caucasica Abich. in loose sandy marl (upper golt).

8. Aucella Coquandi d’Orb. in sandy beds (lower golt)

9. Rhynchonella Deluci Pict. in light-gray sandstone above the beds with Perna Mulleti

From the valley of the Keisu near Gimry, in black-gray marly limestone:

1. Inoceramus sulcatus Park.

2. Inoceramus concentricus Park.

From the Gavidara gorge:

1. Inoceramus concentricus Park., according to Abich.

From Koro-Dag, in yellowish-green sandstone:

1. Trigonia cf. Constantii d’Orb.

Between Koro-Dag and Kunichi, in clayey geodes:

1. Rhynchonella Deluci Pict.

From the Taugist gorge:

1. Rhynchonella Deluci Pict.

Between Boshuk and Meni, in light-gray sandstone:

1. Rhynchonella Deluci Pict.

From Koshkardy, in yellowish sandstone:

1. Trigonia Abichi Anth.

From Aimak, in green sandstone:

1. Thetis major Sow.

From the Akstafa valley:

1. Desmoceras (Puzosia) Majoriarum d’Orb sp.

From Meshilty, in green sandstone:

1. Thetis Caucasica Eichw.

2. Aucella Caucasica Abich.

From Kharikzily:

1. Trigonia aliformis Park., according to Abich.

From the valley of the river Koisu:

1. Thetis minor Sow. from geodes in sandstone, according to Abikh.

Relying on these lists and on Abikh’s data, Anthula divides the Dagestan Gault into three horizons from top to bottom:

Sandy marls with Aucella Caucasica Abich.
Light-gray sandstone with Rhynchonella Deluci Pict. and Thetis major Sow.
Loamy-sandy beds with Aucella Coquandi d’Orb. and Panopaea acutisulcata Desh.

The Aptian is represented very abundantly in Anthula’s material. Anthula assigns the following forms to the Aptian.

From the valley of Akusha:

From green sandstone,

1. Trigonia nodosa Sow.
2. Perna Mulleti Leym.

From marl

1. Crioceras Waageni Anth.

From weathered sandstone

1. Parahoplites Treffryanus Karst.

From gray sandy limestone

1. Hoplites Deshayesi Leym.

From calcareous glauconitic sandstone

1. Panopaea plicata Sow.

From gray calcareous sandstone

1. Thetis major Sow.

From shelly breccia

1. Anomia laevigata Sow.

From gray marly sandstone

1. Gervillia Forbesiana d’Orb.
2. Pinna Robinaldina d’Orb.

From geodes in gray clay

1. Belemnites sp.
2. Crioceras Orbignyi Math. sp.
3. Acanthoceras Martini d’Orb. sp. var. caucasica Anth.
4. Parahoplites aschiltaensis Anth.
5. Parahoplites angulicostatus d’Orb. sp.
6. Parahoplites Melchioris Anth.
7. Desmoceras Akuschaense Anth.
8. Desmoceras falcistriatum Anth.
9. Ptychoceras off. Puzosianum d’Orb.
10. Lytoceras latericarinatum Anth.
11. Lytoceras (lìcatrites) Abichi Anth.
12. Lytoceras (Tetragonites) heterosulcatum Anth.
13. Lytoceras (Tetragonites) Duvalianum Anth.
14. Phylloceras In ettardi Rasp.
15. Phylloceras subalpinum d’Orb.
16. Phylloceras Velledae Mich.
17. Phylloceras Bouyanum d’Orb.

1. Thetis minor Sow.
2. Trigonia Akuschaensis Anth.

From the road from Akusha to Derbent.

From gray marly limestone: 1. Parahoplites Uhligi Anth.
From yellow limestone: 1. Parahoplites Abichi Anth.
2. Parahoplites multispinatus Anth.

From Khodzhal-Makhi.

From gray sandstone: 1. Trigonia nodosa Sow.
From dark-gray oolitic sandstone: Alectryonia Milletiana d’Orb.
From glauconitic green sandstone: Nautilus Neckerianus Pict. et Camp.
Astarte trapezoidea Anth.
From gray sandy limestone: Hoplites Deshayesi Leym.
From marl: Parahoplites Sjögreni Anth.
From gray clay: Lytoceras belliseptatum Anth.
From yellow limestone: Parahoplites Melchioris Anth.
Parahoplites angulicostatus Anth.

From Ashil’ty.

From sandy limestone: Parahoplites aschiltaensis Anth.
From yellow limestone: Pachydiscus Waugeni Anth.
Phylloceras ex aff. Velledae Mich. sp.
Crioceras ramososeptatum Anth.

From Turchi-Dag, according to Abich.

From yellow limestone: Acanthoceros Martini d’Orb.
Hoplites Deshayesi Leym.
Lytoceras (Tetragonites) Duvalianum d’Orb.
Phylloceras Bouyanum d’Orb.

From the Gavvidar pass.

From green marly sandstone: Gervillia aliformis Sow.
From dark-gray oolitic sandstone: Alectryonia Milletiana d’Orb.

Between Khadzhal-Makhi and Ul’lu
in green sandstone: Gervillia aliformis Sow.

On the slope of Cherkatmer, on the left bank of the Andi Koisu River.
Gervillia Forbesiana d’Orb.

From Meshelty
in gray marly sandstone: Pinna Robinaldina d’Orb.

From Tsatanikh
in gray calcareous sandstone: Thetis mayor Sow.

Between Kumuk and Uluchra, according to Abich,
in loose marl: Hoplites Deshayesi Leym.

Acanthoceras Martini d’Orb.

Between the Irgani and Shuro passes,
in glauconitic sandstone, Panopaea plicata Sow.

From Kashkashily,
in green sandstone: Trigonia Caucasica Bayern.
Cyprina bernensis Leym.
Perna Mulleti Leym.

From Gunib,
in ash-gray sandstone: Trigonia caudata Ag.

From Tanus,
in ash-gray sandstone: Trigonia caudata Ag.

Between Orakly and Murkhukh,
Astarte trapezoidea Anth.

On the basis of the forms studied by him and of the data of Abich and Schögren, Anthula arrives at the following general scheme of the Aptian deposits of Dagestan, reckoning from top to bottom.

Light-gray sandy marls with Anomia laevigata Sow. and Thetis major Sow.

Dark-gray clays with Perna Mulleti Leym., Thetis major Sow., Thetis minor Sow., Trigonia aliformis Park., Trigonia nodosa Sow., etc.

Dark-gray clayey marl with spherical concretions of limestone, with Phylloceras Velledae Mich., Lytoceras Duvalianum d’Orb., Hoplites Deshayesi Leym., Parahoplites Melchioris Anth., etc.

The indications of the age of one or another form in different places of Anthula’s work are not always consistent, and therefore in places it has been necessary to make a choice in the presentation. The Neocomian of Dagestan contains, according to Anthula, the following forms:

From Gunib:

1. Panopaea cylindrica Pict. et Camp. in clayey sandstone.
2. Ptychomya elongata Anth.
3. Exogyra aquila d’Orb.
4. Alectryonia rectangularis Roem. in yellowish sandstone.
5. Pentacrinus aff. carinatus Roem. from the Neocomian pentacrinid beds.

From Tanus:

1. Panopaea cylindrica Pict. et. Camp. in clayey sandstone.
2. Toxaster gibbus Ag. in gray marl.
3. Toxaster complanatus Ag. in gray marl.

From Shakh-Dag (the road from Kuba to Kris):

1. Cyphosoma cf. Loryi Gr. in yellow and loose sandstone.

1. Holectypus macropygus Des.

2. Rhynchonella multiformis Roem.

3. Rhynchonella lata d’Orb. in oolitic sandstone.

4. Terebratula sella Sow. in brown marl.

5. Alectryonia rectangularis Roem.

6. Timbria corrugata Sow. in yellow oolitic sandstone.

7. Pleurotomaria Daghestanica Anth. in yellow oolitic sandstone.

From Kuduka

Trigonia carinata Ag. in green sandstone.

From Godoberi

1. Trigonia nodosa Sow.

2. Terebratula sella Sow. in brown marl.

3. Rhynchonella multiformis Roem.

From the valley of Akstafa

1. Exogyra aquila d’Orb.

From the fortification Aimak

1. Exogyra aquila d’Orb.

From Cherkata

1. Exogyra cf. Leymerii Desh. in brown sandstone.

From the summit area of Shakh-Dag

1. Exogyra cf. Leymerii Desh.

From Gavvidary

1. Exogyra Couloni d’Orb. in dark-brown sandstone.

From Mount Shamadan

1. Alectryonia rectangularis Roem. in light-brown sandy marl.

2. Toxaster Collegnii Sism. in brown sandy marl.

3. Rhynchonella multiformis Roem.

From the valley of Akushi

1. Perna Mulleti Desh. from sandstone, according to Abikh.

From Turchi-Dag

1. Perna Mulleti Desh. from brown sandy limestone, according to Abikh.

Below Butsrakh

1. Vola (Janira) atava Roem. in dense brown marly limestone.

Shakh-Dag between Lessoi and Shatt

1. Vola (Janira) atava Roem. in green clayey marl.

From the valley of Konkhidalt

1. Terebratula valdensis Lor. in dense brown marl.

2. Rhynchonella multiformis Roem.

Between Boshuk and Meni

1. Terebratula sella Sow. in brown marl.

1. Holaster cf. cordatus in gray marly limestone.

From Prakli

1. Terebratula Sella Sow. in gray marl.

From Ulinaya

1. Terebratula Valdensis Lor. in light-greenish sandy limestone.
2. Toxaster Collegnii Sism. in light-greenish sandy limestone.

Between Khodzhal-Makhi and Tsudakhar

1. Rhynchonella multiformis Roem.

On the basis of these determinations and of the data of Abich and Schegren, Anthula gives the following scheme of the Dagestan Neocomian.

Gray marls with Crioceras Orbignyi Math., Crioceras ramososeptatum Anth. (Khodzhal-Makhi)—in the text they are assigned to the Lower Aptian, but in the table on p. 150 to the Barremian stage.

Sandstones with Lytoceras crebresulcatum Anth. (Racha—the locality whose geographic position was unknown to Anthula)—also the Barremian stage.

Yellowish oolitic sandstone with Ostrea rectangularis, Timbria corrugata, Rhynchonella multiformis—the Hauterivian stage.

Gray marls and limestones—the Hauterivian stage (Shakh-Dag, Gunib, Kharikzila Pass).

Anthula’s work still remains the principal source of our information on the Cretaceous deposits of Dagestan. The small notes by Prof. A. Stuckenberg that appeared later (“A Journey to the Caucasus,” in the Scientific Notes of the Imperial Kazan University, year 68, book 3; 1901) and by Prof. N. Andrusov (“A Journey to the Caucasus in 1898,” in Zemlevedenie for 1901: books I–II) contain no new results.

The “Preliminary Report on a Geological Excursion in Dagestan in the Summer of 1903” published by me in 1904 (Supplement to the protocols of the meetings of the Society of Naturalists at the Imperial Kazan University, No. 232) contains a list of several provisionally determined species and faunistic evidence for the presence in Dagestan of Cenomanian and Turonian deposits.

In volume III of Deshay’s work “Kaukasus,” which appeared in 1907, there likewise are no new data on the Cretaceous deposits of Dagestan. The lists of forms given there (pp. 147–150), determined by Rapp, nevertheless deserve some attention and must be selected here.

The following localities are assigned by the author to the Cenomanian.

p. Kazansky—Collection of cephalopods.

1. Between Khoem and Shando (northern Dagestan)—white marl with

2. Rhynchonella rionensis Anth.

3. Cardiaster alt. pilula Lam.
4. Stegaster Caucasicus Dru.

5. Echinocorys vulgaris Breyn.

6. East of Khoy (northern Dagestan)—marl

7. Pachydiscus aff. Neubergicus Houer emend. Grossonore.

8. Inoceramus Cripsii Mant. var. regularis d’Orb.

9. Echinocorys vulgaris Breyn. var. conica Ag.

10. Southeastern shore of Lake Ezen-am (northern Dagestan); white marl

11. Inoceramus Cripsii Mant. var. typica Zilt., var. decipiens Zilt., var. aloeformis Zaek.

12. Inoceramus cuneiformis d’Orb.
13. Inoceramus sp. aff. latus Mant.
14. Inoceramus Cuvieri Sow.

15. Echinocorys vulgaris Breyn.

16. From the pass between Kuiliar and Urma (northern Dagestan)—white marl.

17. Inoceramus Cripsii Mant.

The locality is assigned to the Turonian.

1. On the eastern slope of the pass between Khadzhal-Makhi and the Saltinskaya station, northeast of Gunib.

2. Inoceramus Brongniarti Sow.

To the Upper Cretaceous, without any more precise determination of age, are assigned the localities:

1. On the western shore of Ezen-am (northern Dagestan)

2. Inoceramus Cuvieri Sow.

3. Stegaster Caucasicus Dru.

4. On the pass between Andi and Botlikh, greenish marl.

5. Inoceramus sp. alt. orbicularis Münst.

The author does not assign any locality definitely to the Gault.

To the Aptian he assigns the localities:

1. Near Lovashi, in a dark sandstone with

2. Parahoplites Uhligi Anth.

3. Parahoplites Aschiltaensis Anth.

4. Parahoplites Déchyi Papp.

5. Near Khadzhal-Makhi, in a dark clayey shale…

1. Acanthoceras Waageni Anth. var.

To the Neocomian there can with certainty be assigned only the locality

1. Below Khorochoy, in brown limestone

2. Rhynchonella multiformis Roem.

To the Lower Cretaceous in general, without more definite indications of locality

1. East of Kharaki, between Boshtlik and Khunzakh, with

2. Parahoplites Uhligi Anth.

3. Thetis caucasica Eihw.

4. From the road to Gunib

5. Pholadomya elongata Münst.

6. Myopsis arcuata Ag.
7. Vola sp. ind.

8. Exogyra Couloni d’Orb.

9. Five versts east of Boshtlik

10. Ostrea Cotteani Coqu.

11. Exogyra Couloni d’Orb.
12. Pecten Carteroni d’Orb.

13. Rhynchonella Gibbsiana Dav.

14. Above Miaresy, near Boshtlik. Sandstone.

15. Panopaea irregularis d’Orb.

16. Lima aubersonensis Pict. et Camp.

17. Between Tando and Boshtlik. Sandstone.

18. Eriphyla Grigoriewi Papp.

19. Exogyra aquila d’Orb.
20. Hinnites Leymerii Desh.
21. Trigonia cf. aliformis Park.
22. Aetostreon latissimum Lam.
23. Alectryonia rectangularis Roem.

II.

Description of the Localities of the Described Fauna

The material that served as the basis for the present article was collected by Prof. A. Stuckenberg and by me during two brief trips in Dagestan from the following localities.

I. Between Dzhungutai and Lavashi, along the road from Temir-Khan-Shura to Khodzhal-Makhi.

No. 1. At the 27th verst of the road there is an exposure of nearly vertical gray and reddish chalky marls, in places with gray concretions. Here Upper Cretaceous fossils were collected.

No. 2. At the 28th verst of the same road there is exposed a rather loose yellowish, strongly sandy marl with numerous Lower Cretaceous fossils.

No. 3. At the same verst, somewhat farther on, there is an outcrop of oolitic limestone, filled with bryozoans, crinoid ossicles, echinoid spines, etc. Here Neocomian forms were collected.

II. Beyond Kizil-Yar, along the same road:

At the 34th verst, an outcrop of white limestone, similar in the character of its fossils to No. 3 between Dzhungutai and Lavashi.

III. Near the aul of Lavashi, along the stream flowing here:

No. 1. Above the aul the stream exposes a strongly sandy gray marl with a mass of Aptian fossils. The beds of marl are inclined rather steeply to the E.S.E.

No. 2. The summit of the mountain above the stream is composed of calcareous tuff-like conglomerate. In it only a fragment of Ostrea was found.

No. 3. Beneath No. 2 lies a weak yellow clayey sandstone, separated above from No. 2 by a bed of elongated concretions.

Beds Nos. 2 and 3 lie almost horizontally, unconformably upon No. 1.

No. 4. One verst above the aul, on the bank of the same stream, there is exposed a yellowish sandy-marly rock, passing into a coarse greenish sandstone with numerous fossils.

No. 5. Fragments and pebbles of No. 1, scattered along the banks of the stream.

No. 6. From beneath No. 1, conformably, there is exposed a loose sandy dark-gray clay with rare fossils.

No. 7. Upon No. 1, conformably, lies a black slaty clay, still higher interbedded with lighter marly layers.

IV. In the vicinity of the aul Khodzhal-Makha.

No. 1. To the southwest of the aul rises a mountain, near the summit of which white chalky limestone is developed; its beds extend WSW and contain a few Upper Cretaceous fossils.

No. 2. Directly beneath No. 1 lies gray platy marl without fossils.

No. 3. Beneath No. 2 lies thinly shaly dark clay without fossils.

No. 4. Beneath No. 3 there again lies white limestone with siliceous nodules, without fossils.

No. 5. Still lower lie light-colored marls interbedded with thin-bedded clays. Fossils are rare.

No. 6. Along the very channel of the r. Kazikumukh Koisu, near the aul, almost black clays are exposed, interbedded with gray sandy marl, with a mass of Aptian fossils.

No. 7. Below rocks Nos. 1–5 there is exposed black or dark-gray marl with completely crushed fossils of the Albian stage.

1. A fragment of a concretion, picked up on the bank of the Koisu and derived, probably, from beds No. 6.

No. 9. Exposure of sandy marl along the Koisu, 2 versts above the aul.

No. 10. Concretions from clays No. 6, collected along the bank of the Koisu.

No. 11. Exposure of sandy marl along the r. Koisu near the aul.

V. In the vicinity of the aul Gergebil.

No. 1. At the aul itself there is exposed white chalky limestone interbedded with thin-bedded clay.

No. 2. At a distance of 1½ versts from the aul, upstream along the stream flowing near the aul, there is exposed dense black shaly marl with completely crushed Albian and Lower Cenomanian fossils.

No. 3. Still higher up the stream, white chalky marls are again interbedded with dark-gray clays. Shells of Inoceramus have been found here.

No. 4. Below the aul, along the same stream, with a dip opposite to that of Nos. 1–3, gray clay is exposed, interbedded with sandy marl.

No. 5. On the road between Gergebil and Khodzhal-Makha, on the bank of the r. Kazikumukh Koisu, gray sandy marl with abundant Lower Cretaceous fossils is exposed.

VI. In the vicinity of the aul Tsudokhar.

No. 1. Immediately above the aul, along the bank of the valley of the Kazikumukh ...

Along the Koisu and the ravine flowing into it there are outcrops of dark clays with concretions, often containing very large ammonites.

No. 2. Upon these clays lie alternating beds of dark clays and white chalky marls.

No. 3. Upon No. 2 lie white and light greenish chalky marls with a poor upper-chalk fauna.

No. 4. Above No. 1, along the banks of the Koisu valley, gray sandy marls are exposed, passing into sandstones with a lower-chalk fauna.

No. 4b. Nearer to No. 1 these marls and sandstones contained Aptian forms (Hopl. Deshayesii).

On my second visit to the aul of Tsudokhar I established that the series of outcrops extending along the river Koisu represents here the northern limb of a large anticline. Having passed through a series of outcrops, I was able to record a general section which, from N. to S., i.e. stratigraphically from top to bottom, has the following form:

Kb. White marly limestone with an upper-chalk fauna—No. 3.

Ka. The same limestone with interbeds of siliceous nodules.

J. Interbedding of dark clays with light marls, possibly the Albian stage (?)—No. 2.

H. Black dense marl with compressed fossils.

G. Clay with concretions containing large ammonites—No. 1.

Fk. Strongly sandy gray marl with Hoplites Deshayesi and other Aptian forms.

Fi. A similar, but denser marl, poor in organic remains.

Fh. A similar marl with a mass of Serpula sp.

Fg. A similar marl with small shells.

Ff. A similar marl with a mass of Exogyra aquila Goldf. (united with Couloni d’Orb). Beneath it is a thin clayey interbed.

Fe. A similar marl with the same fauna; beneath it again gray clay.

Fd. A similar marl with the same fauna; beneath it again gray clay.

Fc. A similar marl with the same fauna; beneath it again gray clay.

Fb. Again the same marl and beneath it again gray clay.

Fa. The same marl with Serpula and small shells.

Eb. Reddish limestone with small brachiopods, crinoid ossicles, and bryozoans.

Ea. The same limestone, but with a sharp predominance of bryozoans.

Dc. Dark sandy marl with Neocomian (rather wholly Aptian) fauna.

VII. Environs of the Saltinskaya station.

No. 1. At 2 versts from the station, on the road to Kupu, there is exposed

white chalky marl with siliceous concretions and poor Upper Cretaceous fauna.

No. 2. Along the road from the station to the aul of Salta, at 1 verst from the station, gray sandy marl with poor fossils is exposed.

No. 3. In No. 2 there is a thin bed with rich Aptian fauna.

VIII. Environs of Gunib.

No. 1. Belongs to the Jurassic system.

No. 2. Above the Russian settlement, on the mountain, hard Neocomian limestones are exposed, with brachiopods, crinoid joints, a mass of bryozoans, and oysters.

No. 3. Similar, but more sandy rocks.

No. 4. Similar, still more sandy rocks.

No. 5. At the summit of the mountain, gray sandy marl is exposed with rich Lower Cretaceous fauna.

The material from all the above-listed localities was collected personally by me.

Prof. A. Stuckenberg supplied material from the following points.

1. Kizil-yar—pieces of limestone with bryozoans, crinoids, etc.

2. Mekete—sandy marls with Aptian fauna.

3. Lavashi—material similar to my material from Lavashi No. 1.

4. Khodjal-Makha—chiefly ammonites from concretions in Aptian clay.

5. Kupa—gray sandy marl with Aptian fauna.

6. Kaka-Makha—material similar to that from Lavashi.

7. Gunib—several fossils, fairly different in preservation.

8. Shakh-Dag—gray sandy marl, sometimes yellowish, with Aptian fauna. I do not know the locality of this point. There are many Shakh-Dags in Dagestan, and in Prof. Stuckenberg’s brief report nothing is said about Shakh-Dag.

III

Descriptive Part.

Phylum Mollusca.

Class CEPHALOPODA,

order Dibranchiata,

suborder Belemnoidea,

family Belemnitidae,

genus Belemnopsis Bayle 1878.

1. Belemnopsis minimus. Lister sp. 1678.

(Plate I, fig. 1).

1. Belemnites minimus. Blainville. Belemnites; p. 75; pl. 4, fig. 1.

2. Belemnites minimus. Sowerby. Mineral conchology. VI; p. 175; pl. 589 fig. 1.

3. Belemnites attenuatus. Sowerby. Mineral conchology. VI; p. 176; pl. 589, fig. 2.

4. Belemnites Listeri. Phillips. Yorkshire II; cited according to 2nd ed. 1835; pp. 92, 178; pl. I, fig. 18.

5. Belemnites minimus. D’Orbigny. Terr. Crét. I; p. 55; pl. 5′ fig. 3—9.

6. Belemnites minimus. Quenstedt. Cephalopoden; S. 463; Taf. 30, Fig. 21—25.

7. Belemnites minimus. D’Orbigny. Prodrome II; p. 122; ét. 19. Albien: No. 1.

8. Belemnites minimus. Pictet et Campiche. Sainte Croix. I; p. 103; pl. XIII, fig. 1—6.

9. Belemnites minimus. Kilian. Montagne de Lure: p. 53.

10. Belemnites minimus. Parona e Bonarelli; Fossili Albiani; p. 107.

11. Belemnites Listeri. Parona e Bonarelli: Fossili Albiani; p. 107.

12. Belemnites minimus. Karakash. Cretaceous deposits of the Caucasus; p. 8; pl. VII, fig. 5.

13. Belemnites minimus. Anthula. Kreidefossilien v. Kaukasus. S. 93.

14. Belemnites (Hibolites) minimus. Jacob et Tobler. Engelberger Aa; p. 20.

15. Hibolites minimus. Karakash. Lower Cretaceous deposits of Crimea; p. 22, pl. I, fig. 17—20.

Several, chiefly very small, specimens, showing similarity especially with Fig. 22 of Quenstedt’s cited plate. One of my specimens is covered with small oblong pits, evidently representing the result of the activity of some parasite. The structure of the alveolar margin is visible to some extent only on one of my specimens.

Similarities and differences. All authors who have written about this species point to the difficulty of distinguishing it from young Bel. semicanaliculatus Blainv. sp. In practice the two species differ more stratigraphically than morphologically. My material is insufficient to say anything new on this question. The question of separating or combining Bel. minimus List. sp. and Bel. Listeri Mant. sp. is disputed. Parona and Bonarelli (l. c.) accept both species as distinct, on the basis of the different form and different relative dimensions of the rostra. N. I. Karakaš again takes both forms as one species. My specimens approach the true Bel. minimus in the sense of Parona and Bonarelli, but are not absolutely identical with it. In view of this small difference in the general form of the rostrum and of the variations of this form in my specimens, I prefer to adhere to a broader understanding of this species.

Locality. Black shaly marl No. 2 in the vicinity of the aul Gergebil (5 rostra and 3 pieces of rock with fragments of rostra).

Distribution. Bel. minimus is generally regarded as a form characteristic of the Albian stage.

Its geographical distribution is broad. In Europe this species has been found almost everywhere where deposits of the Albian stage are known, and it is known in England, France, Germany, Switzerland, and Serbia; it is known in the Crimea and in the Caucasus, in the Transcaspian region, in Algeria, Tunis, and Mozambique.

2. Belemnopsis semicanaliculatus Blainville sp. 1827.

1. Belemnites semicanaliculatus. Blainville. Bélemnites; p. 67,
     pl. I, fig. 13.

2. Belemnites semicanaliculatus. D’Orbigny. Terr. Crét. I; p. 58
     pl. 5, fig. 10—15.

3. Belemnites semicanaliculatus (synon. pars). Pictet et Campiche.
     Sainte Croix I; p. 101.

4. Belemnites semicanaliculatus. Kilian. Montagne de Lure II; p. 30.

? 1897. Belemnites semicanaliculatus (pars). Karakaš. Cretaceous deposits of the Caucasus; p. 7; pl. IV, fig. 1.

? 1899. Belemnites semicanaliculatus (pars). Anthula. Kreidefossilien v. Kaukasus; S. 93.

1. Belemnites (Hibolites) semicanaliculatus. Jacob. Engelberger Aa; p. 7.

2. Belemnites (Hipolites) semicanaliculatus. Kilian. Lethaea geognostica; S. 280.

This species is represented in my material by rather numerous specimens, unfortunately in general very fragmentary. This comparatively large form has a cylindrical rostrum up to 80–90 mm long, usually somewhat compressed laterally. The specimen figured in Fig. 1 of Plate IV by N. I. Karakash (l. c.) differs from mine in having a longer ventral groove, which, however, in its lower part is not always clearly visible. Therefore I am not entirely certain of the identity of the form figured by N. I. Karakash with Bel. semicanaliculatus. Small specimens of Bel. semicanaliculatus are very difficult to distinguish from the following species. A somewhat spindle-shaped form of the rostrum is also characteristic of them, and, it seems, the most stable character is the transverse section, which in Bel. semicanaliculatus at a young age is almost round or somewhat compressed laterally.

Similarities and differences. The species is very close to Bel. aptiensis Stolley, but attains a considerably larger size and has, also at a young age, a rounder or somewhat laterally compressed transverse section.

Occurrence. Saltinskaya st., in gray sandy marl No. 3 (numerous, mostly fragmentary specimens); Kupa (up to 50 fragments collected in a washed-out state); Kaka-Makha (10 fragments from gray sandy marl); Khodzhal’-Makha, No. 11 (4 pieces of gray marl with fragments probably belonging to this same species; in this case the preservation is insufficient for categorical identification).

Distribution. Kilian considers this form characteristic of the upper Aptian and of the Albian stage. Jacob (l. c.) regards it as specifically upper Aptian. It probably also occurs lower, although here there is a difficulty in distinguishing it from the following species.

Its geographical distribution cannot be precisely characterized, since the following form has often been cited under the name Bel. semicanaliculatus.

Only the presence of Bel. semicanaliculatus in southern France and Switzerland is certain.

3. Belemnopsis aptiensis Stolley 1906.

(Pl. I, figs. 2–3).

1. Belemnites semicanaliculatus, D’Orbigny. Terr. Crét. suppl., p. 23; pl. 9, figs. 7–9.
2. Belemnites semicanaliculatus (pars?). D’Orbigny. Prodrome II; p. 112: ét. 18 Aptien: No. 3.
3. Belemnites semicanaliculatus. Pictet et Benevier. Perte du Rhône; p. 19; pl. III, fig. 1.
4. Belemnites semicanaliculatus. Pictet et Campiche. Sainte Croix I; p. 101.
   ? 1861. Belemnites stilus. Blanford. Southern India; p. 4; pl. I, fig. 1–12; pl. II, fig. 1–4.
5. Belemnites semicanaliculatus. Stoliczka. Southern India; p. 201.
   ? 1888. Belemnites semicanaliculatus. Kilian. Montagne de Lure II. pp. 9 and 30 (pars).
6. Belemnites semicanaliculatus (pars?). Karakash. Lower Cretaceous deposits of the Caucasus; p. 7; pl. IV, fig. 2.
   ? 1899. Belemnites semicanaliculatus (pars). Anthula. Kreidefossilien v. Kaukasus; S. 93.
7. Hibolites semicanaliculatus. Karakash. Lower Cretaceous deposits of Crimea, p. 22; pl. I, figs. 6, 11, 16.
8. Belemnites (Hibolites) aptiensis. Kilian. Lethaea geognostica p. 280.

Numerical data.

Measurement	Value
Length of the rostrum	47 mm, or in longitudinal diameters 43.5
Length from the end of the rostrum to the bottom of the alveolus	37 mm
Dorsoventral diameter at the anterior end	9 mm
Transverse diameter at the anterior end	9 mm
Dorsoventral diameter at the end of the alveolus	8.5 mm, or in longitudinal diameters 1.00
Transverse diameter at the end of the alveolus	9.5 mm, or in longitudinal diameters 1.12
Greatest dorsoventral diameter	9 mm, or in longitudinal diameters 1.06
Greatest transverse diameter	9.5 mm, or in longitudinal diameters 1.12
Dorsoventral angle of the alveolus	23°

The rostrum is almost cylindrical in the anterior part and somewhat compressed in the dorsoventral direction farther backward. The posterior end is comparatively shortly pointed. In the preserved part of the rostrum the alveolus occupies only slightly more than \(1/5\) of the length and was hardly longer than \(1/4\) of the rostrum. The ventral groove in the alveolar part reaches almost to the end of the alveolus. Two paired, very weak lateral grooves are visible. The axis is subcentral.

Similarities and differences. A form very close to Bel. semicanaliculatus Blainv. sp., but distinguished by its smaller size and by the flattening, in the dorsoventral direction, of the subalveolar part of the rostrum. From Bel. minimus List. sp. young specimens are rather difficult to distinguish; adults, however, are much larger and less spindle-shaped. From Bel. stilus Blanf. sp. it differs, apparently, in having a shorter alveolus; but since Blanford’s species is known to me only from figures, and in these figures the length of the alveolus is visible only in young specimens, I am not certain as to the essential nature of this difference. Stoliczka categorically insisted on the identity of Bel. stilus and Bel. semicanaliculatus. In any case, the much higher stratigraphic position of the Indian form makes identity rather unlikely.

Locality. Lavashi: gray sandy marl No. 1 (16 specimens); Lavashi: without precise indication of locality (14 specimens); Lavashi: gray sandy marl No. 5 (15 specimens).

Distribution. This species is regarded as characteristic of Aptian deposits.

Its geographical distribution is probably very extensive, but is difficult to characterize precisely in view of the widespread confusion of this form with Bel. semicanaliculatus Blainv. sp. With this reservation, southern France, Switzerland, the Crimea, and the Caucasus may be cited as undoubted areas of distribution of the species under consideration, and Spain, Morocco, Algeria, and Tunisia as very probable areas.

4. Belemnopsis jaculum. Phillips sp. 1829.

1. Belemnites minimus. Blainville: Bélemnites; p. 75; pl. 5, fig. 5—7.

2. Belemnites jaculum. Phillips. Yorkshire II (2 ed. 1835); p. p. 95 and 179; pl. 3, fig. 1.

3. Belemnites subfusiformis. D’Orbigny. Terr. Crét. I; p. 50; pl. 4, fig. 9—16.

4. Belemnites subfusiformis. Quenstedt. Cephalopoden; S. 444; Taf. 29, fig. 42—43.

5. Belemnites pistilliformis (pars.). Pictet et Loriol. Voirons; p. 5; pl. I, fig. 1—4.

6. Belemnites pistilliformis (pars). Pictet et Campiche. Sainte Croix I; p. 100.

7. Belemnites jaculum. Pavlov et Lamplugh. Les argiles de Speeton; p. 257; pl. VII, fig. 2—4.

8. Belemnites aff. pistilliformis. Karakash. Cretaceous deposits of the Caucasus; p. 9.

1. Belemnites subfusiformis. Noetling. Belemnites-Beds of Baluchistan; p. 4; pl. I, fig. 4—14.
2. Hibolites subfusiformis. Karakash. Lower Cretaceous deposits of Crimea; p. 21; pl. I, fig. 9, 10 and 15.

To this species I assign 3 specimens. A careful comparison of the larger of them (which preserves part of the phragmocone) with the figures and descriptions of Bel. jaculum (subfusiformis), chiefly with those given for this species by Prof. A. P. Pavlov, made it impossible to detect any difference. The same may be said of the two smaller specimens, although in their case the comparison could only be less complete and concerned almost exclusively the external characters of the rostrum.

Similarities and differences. I cannot decide which of the two names of the present species, Bel. jaculum or Bel. subfusiformis, has priority, and I adopt the former for the same reasons as Prof. Pavlov, i.e., as the name giving less occasion for confusion. Prof. Pavlov clearly showed the difference between Bel. jaculum (subfusiformis) and pistilliformis Blainv. sp., but, in my opinion without sufficient grounds, he replaces the name pistilliformis with the new name pistillirostris. The distinction of young specimens from Bel. aptiensis presents serious difficulties and essentially comes down only to a slightly more evident spindle-shaped form of the rostrum and a more distinct development of the lateral grooves.

Locality. Tsudakhar No. 4 F. (3 specimens).

Distribution. A form essentially Neocomian, known both in the Valanginian and Hauterivian, and also in the Barremian, although its citations must be treated with caution in view of confusion with Bel. pistilliformis Blainv. sp.

Its geographical distribution is broad and includes England, northern Germany, France, Switzerland, Spain, North Africa, Crimea, the Caucasus, Baluchistan, India, Madagascar, and even the polar regions (King Charles Land).

5. Belemnopsis sp. 1.

A fragment of a belemnite phragmocone, showing a distance between septa of 2 mm, with the diameter of the upper end 13 mm, of the lower end 6 mm, and a total length of 25 mm. The alveolar angle is about 30°.

Similarities and differences. It might belong to Bel. jaculum or semicanaliculatus.

Locality. Lavashi.

6. Belemnopsis sp. 2.

A fragment of a fairly large phragmocone. The distance between the septa is 3 mm.

Locality. Khodzhal-Makha.

7. Belemnopsis sp. 3.

A fragment of the alveolar part of a large rostrum with a ventral groove. The fragment is deformed, and a more precise determination is impossible.

Locality. Kaka-Makha.

8. Belemnopsis sp. 4.

An indeterminable fragment of a small rostrum in light-colored marly limestone. The two-layered structure is clearly visible (belemnite within belemnite).

Locality. Gergebil No. 1.

Order Ammonoidea,

family Prionotropidae,

genus Schloenbachia Neumayr 1875.

9. Schloenbachia symmetrica Fitton sp. 1836.

1. Schloenbachia symmetrica. Karakash. Cretaceous deposits of the Caucasus; p. 17; pl. VI, fig. 2.

See also the synonymy there.

Strongly compressed small specimens are identical with the specimens of similar preservation figured by Prof. N. I. Karakash. The state of preservation does not allow anything new to be said about this species.

Similarities and differences. Pictet and Campiche (Sainte Croix I; p. 310) are inclined to unite this species with Schl. Colladoni Pictet et Roux sp. (Grès verts; p. 89; pl. 8). N. I. Karakash also agrees with their opinion. Owing to the poor preservation of my material, I can say nothing definite on this matter. Perhaps it is better to refer this species to the genus Mortoniceras Meev.

Locality: Gergebil No. 2 in black shaly marl (3 specimens); Khodzhal-Makha in similar, but gray marl No. 7 (1 specimen).

Distribution. This species is known from the Albian stage.

Its geographical distribution is little known; it is recorded from the Gault of England (Kent), Switzerland, and the Caucasus.

Genus Mortoniceras Meev. 1876.

10. Mortoniceras inflatum Sowerby sp. 1817.

1. Ammonites inflatus. Sowerby. Mineral conchology II; p. 170, pl. 178.

1. Ammonites inflatus. Brongniart. Environs de Paris (in Cuvier: Recherches sur les ossements fossiles, vol. IV). 4 ed. 1834; p. 150; pl. N, fig. 1.

2. Ammonites inflatus, D’Orbigny. Terr. Crét. I; p. 304; pl. 90 (excluding from the synonymy Am. symmetricus Fitton.).

3. Ammonites varicosus inflatus. Quenstedt, Cephalopoden; S. 211; Taf. 17, fig. 2.

4. Ammonites inflatus. D’Orbigny. Prodrome II; p. 124 ét. 19 Albien No. 46; p. 146 ét. 20 Cénomanien No. 15.

5. Ammonites inflatus (pars). Pictet et Campiche; Sainte Croix I; p. 178; pl. XXI, Fig. 5; pl. XXII Fig. 3—4.

6. Ammonites inflatus. Stoliczka. Southern India; p. 48; pl. XXVII, XXVIII, XXIX, XXX, fig. 1—3.

7. Schloenbachia inflata. Kossmat. Südindische Kreideform. I; S. 185; Taf. XXIII, Fig. 1—2; Taf. XXIV, Fig. 1.

8. Schloenbachia inflata. Karakash. Cretaceous deposits of the Caucasus; p. 16, pl. VI, fig. 1—3.

9. Schloenbachia (Mortoniceras) inflata. Boule, Lemoine, Thevenen. Diego-Suarez.; p. 40; pl. IX, fig. 7—10; pl. XI, fig. 1.

Strongly flattened fragments. In sculpture they are close to Mortoniceras inflatum, being identical with specimens of similar preservation figured by N. I. Karakash.

Locality: Gergebil in black slaty marl No. 2 (2 fragments).

Distribution. A guide form for the uppermost beds of the Albian and the lowermost Cenomanian stages. Its geographical distribution may be considered universal, since this species is cited from all parts of the world.

Family Cosmoceratidae.

Genus Scaphites Parkinson 1811.

The genus Scaphites is placed by Zittel (Grundzüge der Palaeontologie. 3 Aufl.; S. 499) in the family Cosmoceratidae. Hyatt (in Zittel. Textbook of Palaeontology; p. 572) places this genus in the group Leptocampyli alongside the family Lytoceratidae. The principal cause of the disagreement is the difference in views on the systematic position of such forms as Desmoceras, Haploceras, Pachydiscus etc., with some representatives of which, according to Hyatt, certain representatives of the genus Scaphites are connected. I prefer Zittel’s point of view, as the more generally accepted one, although I must note that Hyatt’s views, for all their originality, in my opinion have many chances of subsequently proving to correspond closely to reality.

11. Scaphites (?) Sp.

(Plate I, fig. 4).

A completely flattened specimen. The general form recalls Scaphites, but with the present degree of deformation one cannot be certain that we are not dealing with a distorted representative of the genus Crioceras, or even with a normal ammonite. The sculpture consists of numerous fine ribs, multiplying toward the siphonal side by intercalation. In places there is noticeable swelling of the ribs, which, however, may also be an apparent phenomenon caused by deformation.

Similarities and differences. Some resemblance is found to Scaph. plicatellus Roemer (Nordd. Kreidegeb.; S. 91; Taf. XIII, fig. 7) from the Lower Cretaceous marl near Lemförde, but, given the state of preservation of my specimen, there can be no question of identification.

Locality: Gergebil, in black shaly marl No. 2—1 specimen.

Genus Bochianites Lory 1898.

12. Bochianites (?) Sp. 1.

(Plate I, fig. 5).

A fragment of the body chamber, 19 mm long; the height of the cross-section near the anterior end is about 9 mm, the thickness about 10 mm; near the posterior end the height is 8 mm, the thickness 9 mm. The cross-section is elliptical. The fragment is not perfectly straight, but slightly curved, the convex side being the one which, on the basis of the sculpture, I take to be the antisiphonal side.

The sculpture consists of ribs which, beginning near the boundary of the antisiphonal side, run, bending in an arc, across the siphonal side. On the antisiphonal side only very faint flat folds are visible, likewise arcuately bent forward and meeting the ribs at an acute angle near the boundary of the antisiphonal side with the flanks.

Similarities and differences. The form is rather problematic. There is nothing improbable in its representing a fragment of the straight part of Ptychoceras or Hamites.

Locality: Lavashi, gray sandy marl No. 1.

13. Bochianites (?) Sp. 2.

(Plate I, fig. 6).

Fragments of rather large, straight molds, very coarsely preserved in coarse sandstone. Of the sculpture there have survived—

traces of narrow ribs, separated by wide intervals and obliquely encircling the shell.

Locality: Tsulakhar, sandstone Fi (15 specimens); Lavashi, sandstone No. 4a (6 specimens).

Genus Crioceras d’Orbigny 1840.

(Crioceratites Léveillé 1835,)

In 1835 Léveillé established the genus Crioceratites for uncoiled ammonites of the Lower Chalk: Crioc. Duvali and Crioc. Emerici. D’Orbigny, in 1840 (Terr. Crét. I; p. 457), renamed this genus Crioceras and characterized it by a definite mode of coiling of the shell, consisting of a flat spiral with whorls not in contact. At the same time, for uncoiled ammonites with another character of coiling he established other generic names, partly new (Toxoceras, Ancyloceras), partly old ones that had also been used earlier (Scaphites Park., Hamites Park. etc.). In the course of time various investigators observed that an identical mode of coiling is often characteristic of shells with very different other morphological features. On the other hand, a whole series of forms had been described from fragments on which the mode of coiling could not be seen, and the generic determination of such forms remained highly uncertain. Pictet et Campiche, in 1861 (Sainte Croix II; pp. 25 ff.), greatly narrowed the concept of the genus Crioceras, leaving in it only an insignificant number of species distinguished, besides the mode of coiling, also by symmetrical lobes; all the remaining species of the genus were referred by these investigators to Ancyloceras, in view of their resemblance to unquestionable Ancyloceras and the possibility of subsequently finding a hook-shaped living chamber, characteristic of Ancyloceras, also in such species for which at the present moment only the young spiral part of the shell is known.

In 1875 Neumayr (Kreide—Ammoniten; p. 935) came to the conclusion that the greater part of the species assigned to Crioceras and Ancyloceras have a common origin, namely that they descend from Acanthoceras. Therefore he united these species into a single genus—Crioceras, making the generic concept independent of the character of coiling. However, in 1881 the same Neumayr and Uhlig (Hilsammonitiden; pp. 181–184) again arrived at a different conclusion, namely that the species of Crioceras and Ancyloceras descend from different genera of normal ammonites, partly from Hoplites, partly from Acanthoceras; moreover, the origin of part of the species remained unknown. The indicated authors

authors have by now retained the former broad sense of the concept Crioceras Neumayr, pointing only to its provisional character. Crioceras Pictet, which comprised forms with lobes, was soon separated by Uhlig as a distinct genus, Pictetia. Later Haug (Puezalpe; p. 211) attempted to restore the genus Ancyloceras on new grounds. Giving only secondary importance to the character of coiling, he regards as the characteristic feature of Ancyloceras the presence of six rows of tubercles on the adult whorls and a finer sculpture with indistinct tubercles on the young whorls. Hyatt arrives at approximately the same view (in Zittel’s Textbook of Palaeontology, pp. 587–588), according to whom Crioceras has four rows of tubercles, and Ancyloceras six rows of tubercles, which, however, may be present only on part of the shell. On the other hand, species of Crioceras adjoining Douvilleiceras Grossouvre were twice separated into a distinct genus: once by Dumas under the name Ammonitoceras in 1876, and another time by Parona et Bonarelli under the name Astiericeras in 1897. In practice, the majority of authors adhere to a broad understanding of the genus Crioceras in the sense of Neumayr (Zittel, Anthula, partly N. I. Karakash, Sarasin, etc.); v. Koenen attempted to return to the former division according to the character of coiling. Kilian, in “Lethaea geognostica” (pp. 223–225 and 269–274), comes to the conclusion that the genera Crioceras and Ancyloceras sensu Haug are heterogeneous, at the same time showing an inclination to recognize the genus Ammonitoceras Dumas as adequately substantiated. My fairly large material, unfortunately, is on the whole very fragmentary in preservation. Many species, moreover, permit comparison only with species likewise described only from fragments. Therefore there is no possibility of consistently maintaining a subdivision into three genera—Crioceras, Ancyloceras, and Ammonitoceras—which would seem most appropriate in essence. To separate out the forms adjoining Ancyloceras and Ammonitoceras, and to leave the concept Crioceras for the remaining species, which do not lend themselves to genetic classification, appears inadvisable owing to the inconsistency of such a classification and the inequality of the genera thus obtained. Therefore I prefer provisionally to adhere to the broad understanding of the genus Crioceras in the sense of Neumayr.

14. Crioceras (Ancyloceras) Waageni Anthula 1899.

1. Crioceras Waageni. Anthula. Kreidefossilien v. Kaukasus; p. 126;
   Taf. XIII, Fig. 1.

In my material there are several fragments of this species, entirely corresponding to Anthula’s figure and description. Two of

these fragments represent parts of the anterior hook-shaped portion of the shell; one derives from the spiral part.

Similarities and differences. In specific terms, the most important question is the relation of the species under consideration to Crioceras Matheronianum d’Orbigny sp. (Terr. Crét. I; p. 497; pl. 122). The differences cited by Anthula—partly the denser spiral, the shorter straight part of the shell in Crioc. Waageni—are visible only in complete specimens, and, because of the rarity of such specimens, the degree of constancy of these differences cannot be assessed. The difference in the number of intermediate ribs (always 3 in Crioc. Matheronianum, inconstant in Crioc. Waageni according to Anthula) is also poorly maintained, since in Crioceras Matheronianum, according to d’Orbigny, the number of intermediate ribs may fall to two. Kilian (Montagne de Lure; pp. 13, 33–34) holds the view that a whole series of previously distinguished species (Ancyl. Royeri d’Orb., Ancyl. varians d’Orb., Toxoceras Honorati d’Orb.) are varieties or fragments of different parts of Crioc. Matheronianum. With such a view of this latter species, the independence of Crioc. Waageni becomes still more doubtful. Nevertheless, the lesser evolution of Crioc. Waageni is undoubtedly a feature indicating the great primitiveness of this form. Therefore I prefer, at least provisionally, to retain for it a separate specific name.

Distribution. Crioceras Waageni is known from the Aptian deposits of the Caucasus (vicinity of Kutais and an unknown locality, perhaps the valley of the Akusha according to Anthula).

Generic determination. Closely adjoining Crioc. Matheronianum, Crioc. Waageni belongs to the genus Ancyloceras sens. Haug, being a close relative of the typical form of this genus.

15. Crioceras (Ancyloceras) cf. Bowerbanki. Sowerby sp. 1837.

1. Crioceras Bowerbanki v. Koenen. Neocomammonitiden; S. 247;
   Taf. XXXVII, Fig. 4; Taf. XLII, Fig. 2.

See the synonymy there.

A fragment of an enormous specimen; length of the fragment about 55 mm, greatest diameter of the cross-section 130 mm; the entire fragment consists of air chambers. The ribs reach 12 mm in height, and their middles are separated from one another by 60 mm; on the antisiphonal side the ribs are sharply weakened, and to each rib of the lateral sides there correspond here 2–3 flat folds, arcuately bent forward; on the siphonal side the ribs are likewise considerably weakened.

Similarities and differences. The similarity to Crioceras Bowerbanki is almost complete; in the English form, however, the ribs on the siphonal side appear to be somewhat more strongly developed.

Locality: Lavashi, in gray sandy marl no. 5 (1 specimen).

Distribution: Aptian deposits of southern England and northern Germany.

Generic determination: Haug (Puezalpe; p. 215) assigns the species under consideration to Ancyloceras, uniting Crioc. Bowerbanki and Crioc. Hillsii Sow. into a single species. Kilian (Lethaea geognostica; p. 273) regards it as a member of the group Ancyloceras Benauxianum d’Orb. This latter group he connects with Crioc. Baleare Nol., which in turn is a member of the group Crioceras Duvali Léo. sp., linked by the same author with the genus Neocomites Uhlig. Thus, according to this author, the systematic position of the species rather indicates its belonging to Crioceras (although Kilian himself still calls this form Ancyloceras). My fragment provides nothing for judging the position of this species in the system.

16. Crioceras (Ancyloceras) cf. Hillsi Sowerby sp. 1836.

1. Ancyloceras Hillsi. v. Koenen. Neocomammonitiden; p. 361;
   Taf. XXIII, Fig. 4.

See the synonymy there.

Two fragments, covered with rather fine ribs, weakened and sometimes (on the nucleus) almost interrupted on the siphonal side, and strongly weakened on the antisiphonal side. In its complexity, with an unpaired structure of the lobes, the sutural line approaches Crioc. Hillsi. The small dimensions of the fragments (the height of the cross-section in the larger of them reaches only 30 mm) make exact comparison difficult.

Similarities and differences. I cannot indicate distinctive characters from young whorls of Crioc. Hillsi. Pictet et Campiche—Sainte Croix II; p. 46—and then Haug (Puezalpe; p. 215) unite Crioc. Hillsii and Bowerbanki into one species. V. Koenen again makes them separate species and assigns them (though provisionally) even to different genera. Judging from his figures, Crioc. Bowerbanki has somewhat coarser ribs and lower whorls than Cr. Hillsi; my fragments in this respect adjoin Crioc. Hillsi.

Locality. Lavashi, gray sandy marl no. 1 (1 specimen) and no. 5 (1 specimen).

Distribution. Aptian deposits of southern England and northern Germany. V. Koenen (l. c. p. 424) places the species under consideration

in the list of the fauna of the Lower Aptian—the zone with Hopl. Deshayesi.

Generic determination. To Crioceras Hillsi applies everything that was said above concerning Crioceras Bowerbanki.

17. Crioceras aegoceras. V. Koenen. 1902.

1. Crioceras aegoceras. V. Koenen. Neocomammonitiden; S. 328, Taf. XXXVI, Fig. 1—3.

Three fragments, indistinguishable from v. Koenen’s figures. They are exclusively internal casts, covered with sparse and strong ribs, sharply thinning out on the antisiphonal side. The number of ribs on the antisiphonal side is greater than on the lateral sides (a circumstance not mentioned by v. Koenen). In other respects, both in ribbing and in the form of the cross-section, no differences from v. Koenen’s figures are observed. The suture line has been preserved too coarsely for it to be possible to say anything substantial about it.

Locality. Between Dzhungutai and Lavashi in yellow-brown sandy marl No. 2 (2 fragments); Lavashi in gray sandy marl No. 1 (1 fragment).

Distribution. This species was described from Moorberg near Sarstedt and from Behrenbostel in northern Germany, from beds assigned by v. Koenen, provisionally, to the upper part of the Barremian or to the lower part of the Aptian stage.

Generic determination. This species approaches Crioc. Capricorni Roemer sp. (Nordd. Kreidegeb.; S. 92—Ham. capricornu). The position of the latter species in the system is rather isolated. Neumayr and Uhlig (Hilsammonitiden; S. 184) regard Crioc. capricornu as a species of unknown origin. Therefore it seems probable that for Crioc. capricorni, aegoceras, and certain other related, in part still doubtful, species, it will be appropriate to establish a new generic name.

18. Crioceras n. f. ind.

(Table I, fig. 7).

A fragment about 260 mm long; at the anterior end the height of the cross-section is 83 mm, the thickness 81 mm; at the posterior end the height cannot be measured, the thickness is 71 mm. The form of the cross-section is almost round, but the antisiphonal side is somewhat flattened. The sculpture consists of broadly rounded, wide ribs, which on the antisiphonal side nearly converge to nothing, near its margins are swollen tubercle-like, then are weakened and again swollen

near the siphonal side; here the ribs dichotomize and pass across the siphonal side without interruption, but with some weakening in the middle. On the antisiphonal side the ribs are replaced by flat folds, more numerous than the ribs, which proceed forward in an arcuate curve. The lobe line cannot be figured owing to its insufficient preservation; it is rather complex and somewhat recalls that of Crioc. Hillsi.

Similarities and differences. I know of no species of Crioceras in which, at such dimensions, dichotomy of the ribs has been observed. Something similar is figured by Prof. Sinzov (Douvilleiceras-Arten, p. 192, pl. V, fig. 3) on the adult whorls of his Crioc. Lahuseni, but that form has the intervals between the ribs much broader in comparison with the width of the ribs themselves.

Locality. Khodzhal-Makha; judging from its preservation, it probably comes from concretions of the Aptian stage.

Generic determination. A generic determination does not appear possible, apart from the most general assignment to Crioceras. Most probably one may think that the form described should stand apart (perhaps together with Crioc. Lahuseni Sinz; in that case it is Ammonitoceras Dumas?).

19. Crioceras (?) Caucasicum n. sp.

(Plate I, figs. 8–9).

A hook-like curved fragment and several smaller fragments. The length of the first, measured along the siphonal side, is 90 mm.; the height of the cross-section at the anterior end is 21 mm., the thickness 24 mm.; at the posterior end the height is 14 mm., the thickness 17 mm. The form of the cross-section in front is semi-elliptical, behind rounded-suboctagonal.

The sculpture on the posterior young part of the shell consists of strong ribs, the middle parts of which are spaced from one another by 6–9 mm. These ribs bear siphonal, lateral, and umbilical tubercles, of which the siphonal are relatively strong and distinctly individualized, while the umbilical are relatively weak; the lateral stand between them in degree of development. Between the siphonal tubercles the ribs are almost imperceptible; on the flanks they are strong and directed obliquely forward and toward the siphonal side; on the antisiphonal side all the ribs are replaced by flat folds curved forward in an arcuate manner. Between the main ribs there are inserted much weaker intermediate ribs, entirely devoid of tubercles, numbering 1–2 per interval.

The anterior part of the shell (partly the living chamber) bears an entirely different sculpture. On the antisiphonal side the ribs here are weak; somewhat above its boundary, near the bend of the shell, these ribs swell into tubercles, and from each of the latter 2–3 ribs depart in the form of sharp crests, extending radially across the entire shell; in the middle of the siphonal side these ribs are slightly weakened. Still farther forward the tubercles all disappear, the branching of the ribs disappears, and they pass simply in the form of rings around the shell. Here the distance between the centers of the ribs reaches only 3½ mm.

The lobate line, owing to the conditions of preservation, cannot be depicted completely. It is in general simple, has broad lobes and saddles, and in type approaches Douvilleiceras.

Similarities and differences. The sculpture presents some analogy with Crioc. ramososeptatum Anthula (Kreidefossilien v. Kaukasus, S. 127; Taf. XIV, Fig. 4), but Anthula’s species, by the character of its coiling, is a true Crioceras, whereas my form has thus far yielded only hook-shaped parts and almost straight fragments, which completely exclude the possibility of assuming in it a regular spiral at any progressively advanced age. The coiling of my form more nearly recalls Hamites, and only in the extreme case can one suppose in it a small Ancyloceras. Moreover, the sculpture of the adult whorls in Anthula’s species is different: these whorls are higher, and the ribs on them are arranged more closely and are less sharp. The sculpture of the young whorls of Anthula’s species consists of ribs and tubercles arranged more closely and running not obliquely, but radially on the flanks of the shell. Crioc. Lahuseni Sinzow (Douvilleiceras-Arten, S. 192; Taf. V, Fig. 3) is still less similar to my form, showing a different character of coiling and losing the tubercles much later; its adult whorls have a completely different sculpture. The young part of the shell of my species also recalls Ancyloceras asperalum v. Koenen (Neocomammonitiden, S. 372; Taf. XXXVIII, Fig. 9), but this latter form preserves much more of the tuberculate sculpture of the young whorls and has a greater number of intermediate ribs.

Locality: Lavashi in gray sandy marl No. 1 (3 specimens); Khodzhal-Makha in similar marl (2 specimens); Khodzhal-Makha in the same marl No. 11 (1 specimen).

Generic determination. In the character of coiling, my form, in all probability, approaches Hamites Park., but undoubtedly belongs to the Cosmoceratidae and therefore cannot be referred to

this genus. According to Hyatt it should be referred to Ancyloceras, since it bears 6 pairs of tubercles, although only on the young whorls. In my opinion the young whorls of the species under consideration, both in sculpture and in the suture line, most closely recall certain species of Douvilleiceras Grossouvre, and the change of sculpture with growth is likewise not without some analogies with the relatives of Douvilleiceras Martini d’Orb. sp. Therefore I am inclined to bring my form closer to the genus Ammonitoceras Dumas. The chief objection to referring my species to this genus is the mode of coiling, but this character, in my opinion, has only secondary significance.

20. Crioceras aff. ramososeptatum Anthula 1899.

(Plate I, fig. 10).

1. Crioceras ramososeptatum. Anthula, Kreidefossilien v. Kaukasus; S. 127; Taf. XIV, Fig. 4.

A fragment, already lacking tubercles, but still representing a portion of the body chamber. The character of the ribbing and the visible parts of the suture line correspond to Anthula’s data. The differences consist: 1) in the fact that on my fragment, in one particular case, branching of the ribs is observed; 2) in the fact that my fragment is plainly asymmetrical; its right side is flatter than the left and bears a longitudinal (spiral) groove; inward from this groove the ribs run obliquely outward and backward; on the outer side of the groove the ribs form an arcuate bend forward. The left side of my fragment has an entirely normal appearance. I see no data that would make it possible to decide whether in the present case there is an individual anomaly or a normal stage of growth.

Locality: Khodzhal-Makha.

Distribution: Anthula refers Crioc. ramososeptatum to the Lower Aptian.

Generic determination. The development of the sculpture shows certain analogies with the preceding species, and therefore Crioc. ramososeptatum might be brought closer to Ammonitoceras Dumas. However, a serious obstacle to such a rapprochement is presented by the suture line, which in Anthula’s species and in my fragment is very complex. Therefore a closer approach of this species to the group of Ancyl. Renauxianum d’Orbigny seems more suitable; in representatives of this group similarity is observed in the suture line, and partly also in the sculpture (Ancyl. Fallauxi Uhl.). In that case the species under consideration should be assigned to Ancyloceras d’Orb.

21. Crioceras sp. ind. 1.

(Table I, fig. 11)

A fragment of a completely flattened uncoiled ammonite. Fairly strong ribs and strong siphonal tubercles are visible. Specific determination is impossible, although a resemblance to the young whorls of Crioc. Caucasicum n. sp. cannot be denied.

Locality: Gergebil, in black shaly marl no. 2 (1 fragment).

Generic determination: Generic determination is quite inconceivable, since this form can scarcely be compared with any uncoiled ammonite with tuberculate young whorls.

22. Crioceras cf. furcatum. D’Orbigny sp. 1840.

1. Ancyloceras furcatus. D’Orbigny. Terr. Crét. I; p. 509; pl. 127 fig. 8–11.
2. Ancyloceras furcatus. D’Orbigny. Prodrome II; p. 101; ét. 17 Néocomien: B. Supérieur, no. 628.
3. Ancyloceras furcatus. Pictet et Campiche. Sainte Croix II: p. 45.
4. Crioceras (Ancyloceras) cf. furcatum. Karakash. Cretaceous deposits of the Caucasus: p. 30; pl. IV, fig. 17.

Several fragments approach this species. The most complete of them represents the anterior bend of the shell and is entirely the living chamber. It presents no essential differences from the cited illustrations, but reaches a somewhat larger size in comparison with d’Orbigny’s figure, being in this respect closer to the figure in N. I. Karakash. In view of this circumstance, and also in view of the fact that identification of the Aptian form with the Neocomian one is in itself somewhat doubtful, I determine this form as cf.

Locality. Gergebil, in gray sandy marl no. 5 (1 fragment); Lavashi, in gray sandy marl no. 4 (3 fragments).

Distribution. Crioc. furcatum is distributed chiefly in the Barremian stage of France, Switzerland, and Algeria. N. I. Karakash cites it from the Aptian deposits of the Caucasus, as cf.

Generic determination. Kilian (Lethaea geognostica; p. 272) assigns Crioc. furcatum to the group Crioceras Tabarelli Ast. = Acrioceras Hyatt 1900 (Zittel. Textbook of Palaeontology; p. 585). I have nothing to say regarding such a generic determination.

23. Crioceras aff. dissimile. D’Orbigny sp. 1840.

(Plate I, figs. 12–13)

1. Hamites dissimilis. D’Orbigny. Terr. Crét. I; p. 529; pl. 130, fig. 4–7.
2. Hamites Emericianus. D’Orbigny. Terr. Crét. I; p. 530; pl. 13, fig. 8–12.
3. Hamulina Emericiana. D’Orbigny. Prodrome II; p. 66; ét. 17 Néocomien: A. Inférieur, No. 70.
4. Hamulina dissimilis. D’Orbigny. Prodrome II: p. 102; ét. 17 Néocomien: B. Supérieur, No. 645.
5. Hamulina dissimilis. Pictet et Campiche. Sainte Croix II; p. 103.
6. Crioceras dissimile. Kilian. Montagne de Lure I; p. 232.
7. Crioceras dissimile. Haug. Puezalpe; S. 209.

I assign here several fragments. One of them is 13 mm long, with the height of the cross-section at the anterior end 6 mm and the thickness 8 mm, and at the posterior end, respectively, 5 mm and 6 mm. It has ribs of two kinds. The principal, thicker ribs bear on each side two well-marked tubercles, the siphonal tubercles being stronger than the lateral ones. This closely recalls Ham. Emericianus d’Orb., except for the circumstance that the number of intermediate ribs on my specimens is smaller, namely, in one interval there is only one rib.

Toward the end of the fragment the ribs begin to join in pairs in the lower third of the height of the whorl, the tubercles disappear, and new tubercles appear at the point where the ribs unite. This latter sculpture predominates throughout another fragment, 21 mm long (measured along the siphonal side), with the height of the cross-section at the anterior end 12 mm and at the posterior end 9 mm, and the thickness at the anterior end 15 mm and at the posterior end 10 mm; here, rarely, instead of bifurcation, intercalation of ribs is also observed.

Similarities and differences. The sculpture presents a very close analogy to Crioc. dissimile d’Orb. sp. The differences are reduced to the smaller number of intermediate ribs on the young whorls, to the smaller size, and to the higher whorls of the Caucasian form. The latter probably represents an Aptian mutation of Crioc. dissimile. The form described by N. I. Karakasch from the lower chalk of the Crimea under the name Hamulina cf. Emerici apparently has nothing in common with Crioc. dissimile, since it preserves tubercles to a much more considerable size.

Locality. Tsudakhar, in gray sandy marl No. 46 (3 fragments); Khadzhal-Makhi, in a similar marl (2 fragments).

Distribution. Crioc. dissimile is cited from the Barremian deposits of southern France, Tyrol, and the Carpathians; more rarely from the Lower Aptian.

Generic determination. Kilian (Lethaea geognostica; p. 272) assigns this form to the same group, Crioc. Tabarelli, as the preceding species, and consequently to Acrioceras Hyatt.

24. Crioceras elatum. V. Koenen sp. 1902.

1. Ancyloceras elatum. V. Koenen. Neocomammonitiden; p. 375; Pl. XXXVIII, Fig. 8; Pl. XLV, Fig. 9; Pl. LIII, Figs. 6–7; Pl. XL, Fig. 2.

Under this specific name v. Koenen describes several fragments which, judging from the figures and description, differ considerably from one another. My fragments differ only in their smaller size and represent still younger parts of the shell. The sculpture, consisting of ribs passing without interruption across the siphonal side and bearing rather weakly developed lateral and siphonal tubercles, as well as the rounded transverse section of the whorls, fully corresponds to v. Koenen’s figures. The character of the ribbing comes closest to Fig. 7, Pl. LIII, of that author.

Occurrence. Lavashi, in gray sandy marl No. 1 (3 specimens).

Distribution. Described from the Lower Aptian (zone with Hopl. Weissi) of northern Germany.

Generic determination. V. Koenen points out the similarity of the species under consideration with Crioc. Silesiacum Uhlig, from which Uhlig made the type of his genus Leptoceras Uhlig, 1883. Correct opinions regarding the independence and scope of this genus were expressed by Sarasin (Chatel–Saint.–Denis II; pp. 103 and 146). Nevertheless, the relationship of Crioceras elatum with the species adjoining Leptoceras seems to me very probable.

25. Crioceras aequicingulatum V. Koenen sp. 1902.

1. Hamites aequicingulatus V. Koenen. Neocomammonitiden; p. 394; Pl. XXXVII, Figs. 5–6.

To this species I refer several fragments that show no differences from the various parts of the shell figured by v. Koenen.

Occurrence. Khodzhal-Makha, in gray sandy marl No. 8 (1 specimen); Khodzhal-Makha, in gray sandy marl No. 11 (1 specimen); Lavashi, in gray sandy marl No. 1 (1 specimen).

Distribution. Described from the Lower Aptian (zone with Hopl. Deshayesi) of northern Germany.

Generic determination. This species cannot be regarded as Hamites in the sense in which that name is used, for example, in the latest edition of Zittel’s textbook (Grundzüge der Palaeontologie, 3rd ed., p. 481), since its lobate line corresponds to the type Cosmoceratidae, and not Lytoceratidae. Hyatt’s conception of the genus Hamites (Zittel, Textbook of Palaeontology, p. 586) is quite different, and the assignment of the species under consideration to the genus Hamites in Hyatt’s sense encounters only the obstacle that in Crioc. aequicingulatum there are nevertheless some indications of siphonal tubercles. It seems that the most justified course would be to bring this species closer to the preceding one, i.e. ultimately to Leptoceras Uhlig.

26. Crioceras sp. ind. 2.

(Pl. I, fig. 14)

Fragment of a body chamber; almost straight; length about 13 mm, height of the cross-section at the posterior end about 9 mm, thickness about 8 mm. The shape of the cross-section is elliptical. The siphonal and antisiphonal sides are more convex than the lateral sides. The surface is covered with high rounded ribs, the crests of which on the siphonal side are separated from one another by 3 mm. On the antisiphonal side these ribs turn into flat folds and are slightly bent forward. In the middle of the siphonal side they are slightly weakened.

Similarities and differences. It is somewhat similar to Crioc. aequicingulatum v. Koen. sp. (see above), but differs in its higher and narrower ribs, more strongly weakened on the antisiphonal side; moreover, the ribbing of the Caucasian form is not so regular.

Locality: Lavashi, in gray sandy marl No. 1 (1 specimen).

Generic determination. The closest generic determination is impossible. I can only refer to what was said for the preceding species and to the similarity of the form under consideration to this latter.

27. Crioceras cf. unclosum. v. Koenen sp. 1902.

(Pl. I, fig. 15).

1. Hamites(?) unclosus v. Koenen. Neocomammonitiden; p. 393; Pl. XXXV, Fig. 13.

Fragment 15 mm long, 6 mm in diameter at the anterior end, 4 mm at the posterior end; consists of air chambers; there is also a matching fragment of a body chamber. The sculpture is the same as

Hamites undosus v. Koen, but larger in size, and the suture line is correspondingly somewhat more complex; in particular, the siphonal saddle has a quadrangular, not triangular, form. Whether these differences are age-related or specific is difficult to say.

Locality. Lavashi, in gray sandy marl No. 1 (2 specimens).

Distribution. Lower Aptian of northern Germany (zone with Hopl. Deshayesi).

Generic determination. I find no data sufficient for the generic determination of this form either in my material or in v. Koenen’s description and figures.

28. Crioceras cf. Blancheti Pictet et Campiche sp. 1861.

(Table I, fig. 16).

1. Ancyloceras Blancheti. Pictet et Campiche. Sainte Croix II; p. 33; pl. XLVII.

2. Ancyloceras (?) cf. Blancheti. Karakash. Cretaceous deposits of the Caucasus; p. 32; pl. IV, fig. 16.

3. Ancyloceras Blancheti. Sommermeier. Aptien und Albien v. nördl. Peru; S 377.

A fragment of the body chamber. Sharp, unbranched ribs, weakened on the antisiphonal side and scarcely lowered on the siphonal side, separated by relatively broad intervals, recall Cric. Blancheti. The ribs are nevertheless placed somewhat more closely than in the Swiss form and bear no traces whatever of tubercles. The fragment is completely straight. It is not impossible that in the present case a new form is involved.

Locality. Khodzhal-Makha, in gray sandy marl.

Distribution. Crioc. Blancheti has been described from the lower and partly the middle part of the Albian stage of Switzerland, partly of southern France and Peru. N. I. Karakash cites it, as cf., from the Aptian stage of the Caucasus.

Generic determination. The generic determination presents considerable difficulties. A certain analogy in sculpture is observed with Taxoceras Cornuelianum d’Orb. (Terr. Crét. I; p. 484; pl. 119, fig. 5—9). Kilian assigns this latter species to Leptoceras Uhlig (Lethala geognostica; S. 272).

29. Crioceras sp. ind. 3.

(Table I, fig. 17)

A fragment about 25 mm long, measured along the siphonal side, belonging partly to the body chamber and partly to the air chambers.

frame; at the posterior end the height of the cross-section is 8 mm, the thickness 7 mm; at the anterior end the height is 10 mm, the thickness cannot be measured. The form of the cross-section is elliptical, with the siphonal and antisiphonal sides somewhat flattened.

The sculpture consists of fine ribs, the distance between whose middles on the siphonal side is somewhat less than 1 mm. On the antisiphonal side the ribs are weakened and bend somewhat forward; in the upper third of the lateral sides their number increases somewhat owing to individual cases of branching and intercalation; on the siphonal side the ribs are weakly bent forward and are slightly weakened in the middle. One constriction is observed.

Similarities and differences. The form described closely recalls Ancyloceras tenuiplicatum v. Koen. (Neocomammonitiden, p. 377; Taf. XLV, Fig. 11; Taf. LIII, Fig. 4–5). The difference comes down to the absence of distinct tubercles and to the greater density of ribbing in the Caucasian form. In Ancyloceras biplicatum v. Koen. (ibidem; Taf. XLI, fig. 2, 8) the ribs dichotomize more regularly, at least on parts of the shell. Crioceras furcatum d’Orbigny has thicker ribs. It is not impossible that the form described belongs to one of the first two species, but the conditions of preservation and the insufficient study of both species by v. Koenen do not permit a definite identification.

Locality. Tsudakhar, in gray marly sandstone.

Distribution. Ancyl. tenuiplicatum v. Koen. and Ancyl. biplicatum v. Koen. Both are known from the Lower Aptian (zone with Hopl. Weissi) of northern Germany.

Generic determination. It probably should be brought together with Leptoceras Uhlig.

30. Crioceras sp. ind. 4.

(Plate I, fig. 18.)

A small fragment about 13 mm long (measured on the siphonal side); the height and thickness of the cross-section are about 5 mm. The cross-section is rounded, but the antisiphonal side is somewhat flattened.

The sculpture consists of rather regularly dichotomizing fine ribs, almost imperceptible on the antisiphonal side and barely weakened in the middle of the siphonal side. The fragment is evidently asymmetrical: on the right side the ribs dichotomize near the siphonal side, on the left side at mid-height of the whorl.

Near the mouth and near the boundary of the siphonal side with the left lateral side they form small angles, directed with their apices backward. The distance between the centers of the ribs on the siphonal side is about 0.5 mm.

Similarities and differences. The sculpture shows some resemblance to Ancul. biplicatum v. Koen. Neocomammonitiden; S. 379; Taf. XII, fig. 2,8), but differs in its asymmetry and in the absence of noticeable tubercles.

Locality. Lavashi in a gray sandy marl.

Generic determination. There is nothing impossible in this form being close to Heteroceras d’Orbigny 1847 emend Kilian.

31. Crioceras sp. ind. 5.

(Table I, fig. 19).

A fragment about 35 mm long (measured along the siphonal side). At the anterior end the height of the cross-section is 11 mm, thickness 10 mm; at the posterior end the height is 8 mm, thickness 6.5 mm. The cross-section is elliptical. The sculpture consists of flat, broad ribs, the centers of which on the siphonal side are almost 3 mm apart. On the antisiphonal side these ribs are very weak and slightly arcuately bent forward. Near the boundary of the antisiphonal side with the lateral side, on the latter, the ribs bear umbilical tubercles; then, on the flanks, the ribs are greatly widened and sometimes bear, noticeable also on the nucleus, a weak longitudinal furrow, as if indicating a doubling of the ribs; on the upper third of the flanks the ribs bear lateral tubercles; owing to the abrasion of the siphonal side, the siphonal tubercles and the interruption of the ribs on the siphonal side cannot be ascertained with certainty.

Similarities and differences. The sculpture presents certain analogies with Crioc. Orbignyanum Mather, sp. (see Haug. Puezalpe; S. 215: Taf. XI, Fig. 5; Anthula Kreidefossilien v. Kaukasus; S. 125; Taf. XII, Fig. 2). The form described, however, has a coarser sculpture.

Locality. Gergebil in a gray sandy marl No. 5.

Generic determination. It is probably close to Ancyloceras d’Orb. emend. Haug.

32. Crioceras (?) sp. ind. 6.

(Table II, fig. 20).

A fragment of a large form, wholly insufficient for determination. The sculpture consists of very fine and numerous ribs. The traces of the lobate line visible in places do not make it possible to establish its type, and therefore the possibility is not excluded that the form under consideration belongs to Pictetia Uhlig.

Locality. Khodjal-Makha.

Genus Acanthoceras Neumayr 1875.

If one excludes the forms which may quite properly be referred to Douvilléiceras Grossouvre, then in my material there remain only two forms adjoining Acanthoceras. What is to be understood at the present time under this generic name is rather difficult to establish, since different authors take very different views on this matter. Not having sufficient factual data to enter into a detailed discussion of the question of the limits of the genus Acanthoceras, I adopt for it rather broad limits and regard Mantelliceras Hyatt and Metacanthoplites Hyatt as subgenera of Acanthoceras.

Subgenus Metacanthoplites Hyatt 1900.

33. Acanthoceras (Metacanthoplites) cf. Rhotomagense

Brongniart sp. 1822.

1. Ammonites Rhotomagensis. Brongniart in Cuvier, Recherches sur les ossements fossiles; 4. ed. (1834 vol IV; p. 150; pl. N, fig. 2.

2. Ammonites Rhotomagensis. Sowerby, Mineral Conchology. VI, p. 25; pl. 515.

3. Ammonites Rhotomagensis. D’Orbigny. Terr. Crét. I; p. 346. pl. 105, 106.

4. Ammonites Rhotomagensis. Roemer. Norddeutsches Kreidegebirge. II, S. 87.

5. Ammonites Rhotomagensis. Forbes, Santa fe de Bogota; p. 175;

6. Ammonites Rhotomagensis. Quenstedt. Cephalopoden; S. 213. Taf. 17, Fig. 5

7. Ammonites Rhotomagensis. D’Orbigny. Prodrome II; p. 146; ét. 20. Cénomonien № 22.

8. Ammonites Rhotomagensis. Abich. Daghestanfossilien, S. 25.

9. Ammonites Rhotomagensis. Sharpe. Mollusca of the Chalk, p. 33; pl. XVI, fig. 1—4.

10. Ammonites Rhotomagensis. Pictet et Campiche. Sainte Croix I, p. 190; pl. XXV, fig. 1—3.

11. Ammonites Rhotomagensis. Boemer. Geologie von Oberschlesien; S S. 293, 339, Taf. 27, Fig. 1; Taf. 29, Fig. 15.

12. Acanthoceras Rhotomagense. Kilian. Montagne de Lure II; p.p. 61,62.

13. Metacanthoplites Rhotomagenseis. Hyatt in Zittel: “Textbook of Palaeontology”; p. 589; fig. 1232.

Compressed fragments in gray-white chalky marl could belong to this species, since their sculpture appears identical with that of its Western European representatives.

Locality. Khodzhal-Makha, in gray-white chalky marl No. 1 (fragments of 1 specimen).

Distribution. The species is now usually regarded as an index form for the upper zone of the Cenomanian stage.

Its geographic distribution is extremely wide.

In Europe this species is known from England, northern Germany, France, Spain, Switzerland, Italy, Bohemia, the Carpathian countries, the Balkan Peninsula, European Russia, and the Caucasus. In Asia it is reported from Mangyshlak, Syria, Persia, the Tibetan countries, and Japan; related forms are known in southern India. In Africa Acanth. rhotomagense is recorded from Algeria, Tunisia, Angola, and related forms from Madagascar. In North America California and Texas may be cited. In South America, Bogotá.

Subgenus Mantelliceras Hyatt. 1903.

34. Acanthoceras (Mantelliceras) Mantelli Sowerby sp. 1814.

1. Ammonites Mantelli. Sowerby Mineral. Conchology I, 119; pl. 55.

2. Ammonites Mantelli (pars). D’Orbigny Terr. Crét. I; p. 343; pl. 104.

3. Ammonites Mantelli (pars). Roemer. Norddeutsche Kreidegeb. S. 88.

4. Ammonites Mantelli (pars). Reuss. Boehmische Kreide I, S. 22.

5. Ammonites Mantelli. Quenstedt. Cephalopoden; S. 214; Taf. 17, Fig. 8.

6. Ammonites Mantelli (pars). D’Orbigny Prodrome II; p. 146; ét. 20 Cénomanien No. 21.

7. Ammonites Couloni. D’Orbigny. Prodrome II; p. 147; ét. 20 Cenomanien No. 31.

8. Ammonites Mantelli. Sharpe. Mollusca of the Chalk; p. 40; pl. XVIII, fig. 4, 6, 7.

9. Ammonites Mantelli. Pictet et Campiche. Sainte Croix I; p. 200, pl. XXVI.

10. Ammonites Mantelli (pars). Stoliczka. The Cretac. of South. India; p. 81; pl. XLI. fig. 2—3.

11. Acanthoceras Mantelli. Kilian. Montagne de Lure II; p. 61;

12. Acanthoceras Mantelli. Kossmat. Südindische Kreide II; S 23. Taf IV, Fig. 4.

13. Acanthoceras Mantelli. Boule, Lemoine, Thévenin. Diégo Suarez; p. 29. pl VIII, fig. 3.

More or less compressed specimens in light-gray marl differ in no way from Acanth. Mantelli under the relatively broad, usual understanding of this species. Despite the deformed character of the specimens at my disposal, after careful comparison I became fully convinced of their identity with Acanth. Mantelli.

Similarities and differences. Some doubts exist regarding the generic determination of Acanth. Mantelli. My material gives no grounds for entering into a detailed consideration of the question. I therefore adhere to the term most widespread in the literature, Acanthoceras. However, there are certain grounds for regarding Mantelliceras Hyatt as a subgenus of Douvilleiceras Grossouvre, and this point of view apparently has greater chances of success.

Occurrence. Khodzhal-Makha in gray-white marl No. 5 (7 specimens); Tsudakhar in gray-white marl, river (2 specimens); completely flattened fragments from Gergebil in dark-gray shaly marl No. 2 could also belong to this same species.

Distribution. The species is generally regarded as a guide form for the lower part of the Cenomanian stage.

Its geographic distribution is very wide. Acanthoceras Mantelli is recorded from England, northern Germany, France, Bohemia, Bavaria, Switzerland, the Carpathians, the Balkans, western Russia, Italy, northern Africa, the Sahara, Madagascar, Syria, the Turkoman Mountains, India, Texas, and on both sides of the Caucasus Range.

35. Acanthoceras sp.

(plate II, fig. 21).

A fragment of a whorl, covered with rather thick ribs bearing 3 pairs of tubercles on each side, of which the 2nd pair is most strongly developed. Specific determination is impossible.

Similarities and differences. It has some resemblance to Ac. pseudo-Lyelli Parona et Bonarelli (Fossili Albani; p. 99; tav. XIV, fig. 1—2) from the Albian stage of Escragnolles, but an exact comparison is impossible because of the mutilated condition of my fragment.

Occurrence. Gergebil in yellowish-gray sandy marl No. 5.

genus Douvilleiceras Grossouvre 1893.

I somewhat narrow the scope of this genus in comparison with its usual present understanding, which was established by Jacob. Jacob assigns to Douvilleiceras the whole group Parahoplites Aschiltaensis Anthula (Jacob. Clausages; p. 407). Typical Douvilleiceras of the group

Martini d’Orb., sp. are abundantly represented in my material and, in their entirety, differ sharply from the equally typical and equally abundantly represented Parahoplites of the Aschiltaensis Anthula group. The differences concern both the sculpture, which in Douvilleiceras constantly tends to weaken in the middle of the siphonal side, and the general form of the shell, which in Douvilleiceras is in general much more inflated, and the lobate line, which in Douvilleiceras shows a characteristically reduced first lateral saddle. It is, of course, impossible to deny the possibility of transitions between both generic groups, but in the Caucasian Aptian they are distinctly different. On the generic determination of Parahoplites Aschiltaensis Anth. see below.

36. Douvilleiceras Martini d’Orbigny sp. 1840.

(plate II, figs. 22–25).

1. Ammonites Martini. D’ Orbigny. Terr. Crét. I; p. 194; pl. 58, fig. 7, 8, 10. (non 9).

2. Ammonites Martini. Forbes. Lower greensand fossils; p. 354 pl. V, fig. 3.

3. Ammonites Martini. Quenstedt. Cephalopoden; S. 136.

4. Ammonites Martini. D’Orbigny. Prodrome II; p. 113; 18 ét Aptien № 12

5. Ammonites Martini. Abich. Daghestanfossilien.; S. 23.

6. Ammonites Martini. Pictet et Rénevier. Perte du Rhône; p 22.

7. Ammonites Martini. Pictet et Campiche. Sainte Croix. I; p. 253.

8. Ammonites Martini. Pictet et Loriol. Voirons; p. 26.

9. Ammonites Martini. Waagen. Kutch-Cephalopoda; p. 245; pl. LX, fig. 3.

10. Ammonites Martini. Neumayr und Uhlig. Hilsammonitiden; S. 180. Taf XXXV, fig. 5

11. Acanthoceras Martini. Kilian. Montagne de Lure II; p. 10.

12. Acanthoceras Martini. Karakash. Cretaceous deposits of the Caucasus; p. 26; pl. IV, figs. 4, 5, and 8.

13. Acanthoceras (Douvilleiceras) Martini. var. Caucasica Anthula; Kreidefossil. v Kaukasus: S. 122; Taf. XIV, fig. 1—3.

14. Acanthoceras Martini. V. Koenen, Hilsammonitiden; S. 403.

15. Douvilleiceras Martini. Sinzow. Douvilleiceras-Arten; S. 171; Taf. II, fig. 13—17.

16. Douvilleiceras Martini var. Gottschei. Krenkel. Delagoa Bai; S. 144; Taf. XVII, Fig. 4—9.

Numerical data

Specimens	I (mm)	II (mm)	III (mm)	IV (mm)	I (ratio to shell diameter)	II (ratio to shell diameter)	III (ratio to shell diameter)	IV (ratio to shell diameter)	I (ratio to thickness of corresponding whorl)	II (ratio to thickness of corresponding whorl)	III (ratio to thickness of corresponding whorl)	IV (ratio to thickness of corresponding whorl)
Diameter of shell	18	22	27	31	1.00	1.00	1.00	1.00	—	—	—	—
Diameter of umbilicus	5	7	8	9	0.28	0.32	0.30	0.29	—	—	—	—
Posterior whorl: height above the suture	7	9	11	12	0.39	0.41	0.41	0.39	0.58	0.60	0.69	0.63
Posterior whorl: width	6	7	9	10	0.33	0.32	0.33	0.32	0.50	0.47	0.56	0.53
Posterior whorl: thickness	12	15	16	19	0.67	0.68	0.59	0.61	1.00	1.00	1.00	1.00
Preceding whorl: height above the suture	4	5	6	7	0.22	0.23	0.22	0.23	0.67	0.63	0.67	0.64
Preceding whorl: thickness	7	8	9	11	0.39	0.36	0.33	0.35	1.00	1.00	1.00	1.00

A large part of the synonymy cited must be cited ex parte. Douvilleiceras Martini belongs among the polymorphic forms, which must be divided into several species, perhaps connected by transitions, but nevertheless essentially distinct. Prof. Sinzov (l. c.) made such an attempt at subdividing the collective type under consideration, and, in my opinion, the typical form chosen by him is comparatively successful. He also quite correctly indicated the distinguishing characters of this species from Douv. Cornuelianum d’Orb. sp. To what extent the form figured by Forbes (l. c.) can be referred to Douv. Martini sensu stricto is rather difficult to say. In my opinion it differs in its comparatively numerous and strong intermediate ribs, but only very slightly. As regards its large dimensions and its subsequent change with age, these characters are hardly significant: since Forbes did not distinguish all those species which Prof. Sinzov establishes in place of Douv. Martini, it is very difficult to say with which small whorls his unfigured large specimens are connected. Therefore I consider it possible to cite in the synonymy ex parte also Forbes’s indication. One further small reservation concerns the umbilical tubercles. Their presence or absence, in my opinion, can be only a secondary diagnostic ...

feature. As Pictet quite rightly observed, the degree of development of these tubercles is extremely variable, and often on one and the same specimen these tubercles are clear on some ribs and entirely imperceptible on adjacent ones.

With all these reservations, the diagnosis of Douv. Martini s. str. will have the following form.

An inflated form with a broad and deep umbilical funnel and rather thick whorls, involute to approximately \(1/3\); the transverse section of the whorls is broadly elliptical, somewhat suboctagonal. The height of the whorls above the suture is generally less than \(2/3\) of their thickness. The umbilical margin is rounded and lies almost halfway between the lateral tubercles and the suture.

The sculpture consists of main and intermediate ribs. The main ribs are faintly visible on the umbilical side, become distinct near the umbilical margin, and then gradually broaden. On the lateral sides—where these latter begin to converge toward the siphonal side—these ribs bear rather strong conical tubercles. Here the main rib often gives off a weak anterior branch; the principal continuation of the rib passes across the siphonal side, forming on both sides of its middle elongated tubercles. In the middle of the siphonal side the main ribs are considerably weakened. The intermediate ribs are, in general, developed rather irregularly. Those of them which are the result of the branching of the main ribs, mentioned above, generally remain weak and do not bear tubercles; in addition, intercalated ribs also appear. These latter are developed very variably: sometimes they are as thin as the above-mentioned branches of the main ribs, while at other times they scarcely differ from the main ribs and bear distinct siphonal (but not lateral) tubercles. The number of intermediate ribs is variable and may range from 1 to 3 in an interval. The sculpture changes rather considerably with age. It has the character described on shells 25–30 mm in diameter. The young whorls bear rarer main ribs with weakly developed siphonal and well-developed lateral tubercles; the number of intermediate ribs on the young whorls is generally greater, but these ribs are very thin and sometimes barely noticeable. On the living chamber of adult specimens the main ribs are more closely spaced; the intermediate ribs disappear, either becoming similar to the main ones or vanishing; the lateral tubercles become scarcely noticeable, and later become scarcely notice—

and siphonal tubercles. This change in sculpture is found at somewhat different ages, beginning generally at a diameter of 30–40 mm, and sometimes later.

The length of the body chamber reaches \(3/4\) of a whorl, but it may also be greater, since perfectly complete specimens are unknown to me.

The suture line is characterized by an almost equal depth of the siphonal and first lateral lobes and by a characteristically reduced first lateral saddle.

Similarities and differences. From Douvill. Cornuelianum d’Orbigny sp. it differs, as has been partly indicated by Prof. Sinzov (l. c. s.s. 158 et 171), in higher whorls, less uniform development of both branches of the main ribs—whereby the middle branch is always weaker—less weak intermediate ribs, and more developed tubercles. As a result, Douv. Martini and Douv. Cornuelianum have an entirely different habitus. It is more difficult to distinguish it from Douv. subnodosocostatum Sinz., Douv. Tschernyschewi Sinz., and others. On these distinctions see below, under the corresponding forms.

Locality. Khodzhal-Makhi (10 specimens); Gunib (1 specimen). Judging by their preservation, all of them come from concretions in Aptian dark-gray clays. Doubtful small specimens from Shakh-Dag (3 specimens).

Distribution. It is regarded in general as an Aptian, and predominantly as a Lower Aptian, form. At the same time it is necessary to note the possibility, and even the undoubted presence, of confusions with closely related species. These confusions acquire special significance when judging the geographical distribution of Douv. Martini. According to the literature data, its distribution is extremely wide, but it is impossible in this case to verify which citations refer to Douv. Martini and which to closely related species confused with it. With this reservation, for Douv. Martini s. lat. (partly, probably, even together with Douv. Cornuelianum) the following distribution is obtained. In Europe: England, Northern Germany, France, Switzerland, Spain, the southeast of European Russia; in Asia: the Caucasus, the Transcaspian region, India; in Africa: Algeria, Delagoa Bay; in South America: Colombia.

37. Douvilleiceras Stuckenbergi n. sp.

(Plate II, figs. 26–29).

Numerical data.

Specimens	I, mm	II, mm	III, mm	IV, mm	V, mm	I, ratio to shell diameter	II, ratio to shell diameter	III, ratio to shell diameter	IV, ratio to shell diameter	V, ratio to shell diameter	I, ratio to thickness of corresponding whorl	II, ratio to thickness of corresponding whorl	III, ratio to thickness of corresponding whorl	IV, ratio to thickness of corresponding whorl	V, ratio to thickness of corresponding whorl
Shell diameter	17	22	33	34	44	1.00	1.00	1.00	1.00	1.00	—	—	—	—	—
Diameter of the umbilicus	5	6	10	10	13	0.29	0.27	0.30	0.29	0.30	—	—	—	—	—
Last whorl:
Height above the suture	7	10	14	15	19	0.41	0.45	0.42	0.44	0.43	0.70	0.77	0.78	0.79	0.79
Height above the preceding whorl	6	7.5	11	12	16	0.35	0.34	0.33	0.35	0.36	0.60	0.58	0.61	0.63	0.67
Thickness	10	13	18	19	24	0.59	0.59	0.55	0.56	0.55	1.00	1.00	1.00	1.00	1.00
Penultimate whorl:
Height above the suture	5	5	7	8	10	0.29	0.23	0.21	0.24	0.23	0.71	0.63	0.70	0.67	0.71
Thickness	7	8	10	12	14	0.41	0.36	0.30	0.35	0.32	1.00	1.00	1.00	1.00	1.00

A rather inflated form, with a broad and deep umbilical funnel and fairly thick whorls, involute to approximately \(1/3\). The transverse section of the whorls is broad, elliptical, somewhat suboctagonal. The height of the whorls above the suture is in general somewhat more than \(2/3\) of their thickness. The umbilical edge is rounded and lies approximately halfway between the lateral tubercles and the suture.

The sculpture consists of main and intermediate ribs. The main ribs are faintly visible on the umbilical side and then gradually broaden. On the lateral sides—where these latter begin to converge toward the siphonal side—these ribs bear strong conical tubercles; here the main rib gives off a rather weak anterior branch, separated from it by a deepened depression; the main continuation of the rib goes to the siphonal side, forming on both sides of its middle very strong round tubercles. Between these tubercles, at the middle of the siphonal side, the ribs are greatly weakened: often they are almost reduced to a thread. The intermediate ribs are in general weakly developed, lack tubercles, and are partly the above-mentioned anterior branches of the main ribs, while partly they are intercalary. Their number is 1–2 per interval. The sculpture is vari-

changes with age rather considerably. It has the character described at 30–35 mm in diameter. On the young whorls the main ribs are more sparsely spaced; the intermediate ribs are very fine and more numerous; the siphonal tubercles are almost absent at 15 mm in diameter, while the lateral ones remain distinct down to 10 mm in shell diameter; umbilical tubercles are absent. On the body chamber of adult individuals, in the posterior part, the sculpture is distinguished by a greater frequency and weakness of the main ribs, which are almost equal, but in general by a very weak development of the umbilical and lateral tubercles and by an elongate character of the siphonal tubercles. On the anterior part of the body chamber the ribs are much thinner, have an irregular character, are uneven, and the tubercles are almost absent.

The lobate line is like that in Douv. Martini.

Similarities and differences. The species is very close to Douv. Martini, with which it is probably confused in the literature. The differences are reduced to the following: 1. in Douv. Stuckenbergii the whorls are less thick and their height above the suture almost always exceeds \(2/3\) of the thickness; 2. the siphonal tubercles in Douv. Stuckenbergii have a conical, not an elongate, appearance on the whorls of medium size; 3. in Douv. Stuckenbergii there are, on whorls of medium size, rather distinct, though small, umbilical tubercles. The young whorls of both species are difficult to distinguish, but in Douv. Stuckenbergii even on the young whorls the lateral tubercles are considerably stronger than in Douv. Martini.

My form is still more difficult to distinguish from Douv. subnodosocostatum Sinzow (Douvilleiceras Arten, p. 175; Taf. II, fig. 1–8). Prof. Sinzow’s species shows greater variation in the form of the cross-section, and the variety with higher whorls is rather similar to Douv. Stuckenbergii, but nevertheless shows more elongate siphonal tubercles and better-developed umbilical ones. The difference, however, becomes much sharper when larger specimens are compared. In Douv. subnodosocostatum (Taf. II, Fig. 1 in Prof. Sinzow), on the body chamber of a specimen 60 mm in diameter, strong ribs are visible, differing from the ribs of the younger part of the shell chiefly in having weaker tubercles. In Douv. Stuckenbergii, at 44 mm in diameter, on the body chamber the ribs are very weakened, irregular, and the sculpture recalls Douv. Martini in fig. 13 of the same plate of Prof. Sinzow. In view of these differences I regard Douv. Stuckenbergii as a new species. Douv. Tschernyschewi Sintz. (l. c. p. 182; Taf. II, fig. 11–12; Taf III, fig. 2–7) has much better-developed intermediate ribs.

Locality: Khodzhal-Makhi (9 specimens).

38. Douvilleiceras Tschernyschewi Sinzow. 1906.

1. Douvilleiceras Tschernyschewi Sinzow. Douvilleiceras—Arten; p. 182, Pl. II, figs. 11–12, Pl. III, figs. 2–7.

Numerical data.

Character	In millimeters I	In millimeters II	Ratio to shell diameter I	Ratio to shell diameter II	Ratio to thickness of corresponding whorl I	Ratio to thickness of corresponding whorl II
Shell diameter	17	17	1.00	1.00	—	—
Diameter of umbilicus	6	5	0.30	0.29	—	—
Last whorl: height above the suture	8	6	0.40	0.35	0.62	0.56
Last whorl: height above the preceding whorl	7	5	0.35	0.29	0.54	0.45
Last whorl: thickness	13	11	0.65	0.65	1.00	1.00
Previous whorl: height above the suture	5	3	0.25	0.18	0.33	0.50
Previous whorl: thickness	8	6	0.40	0.35	1.00	1.00

To this species I refer small specimens that differ from Douv. Martini and subnodosocostatum by lower whorls, a steeper part of the lateral sides adjoining the umbilical wall, more sparse and broader main ribs, and more strongly developed intermediate ribs, and that show the closest similarity to the cited figures of Prof. Sinzow.

Locality. Khodzhal-Makha (4 specimens), judging by preservation, from Aptian concretions.

Distribution. The species was first described from Mangyshlak and the Caucasus. It is also cited in the Lower Aptian of southeastern France.

39. Douvilleiceras pusillum n. sp.

(Pl. II, figs. 30–32)

1. Douvilleiceras subnodosocostatum var. pusilla-Sinzow. Douvilleiceras—Arten; p. 180; Pl. II, figs. 9–10.

2. Douvilleiceras subnodosocostatum var. pusilla. Jacob. Engelbrg. Aa; p. 15, pl. I, figs. 12–14.

The young whorls, very close to those figured by Prof. Sinzow, proved to be connected with larger specimens sharply differing from Douv. subnodosocostatum. Therefore the form thus obtained must be described as a new species.

Numerical Data.

Specimens	I, in millimeters	II, in millimeters	III, in millimeters	IV, in millimeters	I, ratio to shell diameter	II, ratio to shell diameter	III, ratio to shell diameter	IV, ratio to shell diameter	I, ratio to thickness of corresponding whorl	II, ratio to thickness of corresponding whorl	III, ratio to thickness of corresponding whorl	IV, ratio to thickness of corresponding whorl
Diameter of the shell	17	23	25	29	1.00	1.00	1.00	1.00	—	—	—	—
Diameter of the umbilicus	4	6	6	7	0.24	0.26	0.24	0.24	—	—	—	—
Last whorl: height above the suture	8	10	11	12	0.47	0.43	0.44	0.41	0.80	0.77	0.79	0.80
Last whorl: height above the preceding whorl	6	7	—	10	0.35	0.30	—	0.34	0.60	0.54	—	0.67
Last whorl: thickness	10	13	14	15	0.59	0.57	0.56	0.52	1.00	1.00	1.00	1.00
Preceding whorl: height above the suture	4	5	6	7	0.24	0.22	0.24	0.24	0.67	0.63	0.67	0.78
Preceding whorl: thickness	6	8	9	9	0.35	0.35	0.36	0.31	1.00	1.00	1.00	1.00

A moderately inflated form with a moderately broad but rather deep umbilical depression and with whorls, more than one-third involute, that are rather thick; the transverse section of the whorls is transversely elliptical. The height of the whorls above the suture amounts to about \(4/5\) of their thickness. The umbilical margin is almost imperceptible, and the lateral sides, rounding off sharply, pass into an almost vertical umbilical wall.

The sculpture consists of rather fine ribs, not always clearly divided into principal and intermediate ones. The principal ribs are generally stronger and bear weakly expressed lateral and siphonal tubercles, the latter having an elongated form. The intermediate ribs, being intercalated, are rarely produced as a result of the branching of the principal ribs at the lateral tubercles. Their number, like their strength, is variable. In an interval there are from 1 to 5 of them. On the living chamber of adults the number of intermediate ribs is generally smaller, and the tubercles are often entirely inconspicuous. The young whorls have comparatively frequent principal ribs and very weak intermediate ones. The tubercles are clearest at a diameter of 15–25 mm.

The suture line does not differ essentially from that of Douv. Martini.

Similarities and differences. The weaker development of the sculpture, especially of the tubercles, sharply distinguishes this form from Douv. Martini and the other forms related to it. Douv. Waageni Anthula sp. (Kreidefoss. v. Kaukasus; p. 106; Taf. IX, Fig. 1) loses the tubercles much later.

Locality: Khodzhal-Makhi (7 specimens), judging by their preservation, probably from Aptian concretions; Lavashi in gray sandy marl no. 1 (3 specimens).

Distribution. Prof. Sinzov cites his Douv. subnodosocostatum var. pusilla from the environs of Kislovodsk. Jacob cites it from the upper Aptian of Switzerland.

40. Douvilleiceras intermedium n. sp.

(Plate II, figs. 33—36).

A form combining mixed characters of Douv. Martini, pusillum, and Stuckenbergi.

Numerical data.

Specimens	I	II	III	IV	I	II	III	IV	I	II	III	IV
	\multicolumn{4}{c}{In millimeters}	\multicolumn{4}{c}{Ratio to the shell diameter}	\multicolumn{4}{c}{Ratio to the thickness of the corresponding whorl}
Diameter of shell	13	22	30	35	1.00	1.00	1.00	1.00	—	—	—	—
Diameter of umbilicus	4	6	9	10	0.31	0.27	0.30	0.29	—	—	—	—
Last whorl: height above the suture	6	10	13	17	0.46	0.45	0.43	0.49	0.75	0.71	0.76	0.85
Last whorl: height above the preceding whorl	5	7	11	12	0.38	0.32	0.37	0.34	0.63	0.50	0.65	0.60
Last whorl: thickness	8	14	17	20	0.62	0.64	0.65	0.57	1.00	1.00	1.00	1.00
Penultimate whorl: height above the suture	3	6	7	9	0.23	0.27	0.23	0.26	0.67	0.75	0.70	0.75
Penultimate whorl: thickness	4.5	8	10	12	0.35	0.36	0.33	0.34	1.00	1.10	1.00	1.00

A rather inflated form with a moderately broad but rather deep umbilical depression and fairly thick whorls, involute by more than \(1/3\); the transverse section of the whorls is transversely elliptical. The height of the whorls above the suture is generally more than \(2/3\) of their thickness. The umbilical margin is rounded and lies near the middle of the distance between the lateral tubercles and the suture.

The sculpture consists of principal and intermediate ribs. The principal ribs are faintly visible on the umbilical side, swell slightly, forming barely distinguishable umbilical tubercles near the umbilical margin, and then gradually broaden on the flanks; there, where these latter begin to converge toward the siphonal side, these ribs bear distinct, though small, lateral tubercles. Here, sometimes, a very weak anterior branch departs from the principal rib; the rib itself—

the main rib passes across the siphonal side, forming on both sides of its middle very sharp, elongated umbonal tubercles. The intermediate ribs are generally weak and irregular. Usually they are intercalated, and their number is 1, more rarely 2, in an interval. Such sculpture predominates on shells 25–30 mm in diameter. On the young whorls the tubercles are developed more distinctly, branching of the ribs is observed more often, and the number of intermediate ribs is greater. The youngest whorls, in the relative frequency of the main ribs, recall Douv. pusillum. The adult living chamber is characterized in its posterior half by the absence of intermediate ribs, and in its anterior half by a general weakening and irregularity of ribbing.

The lobate line is typically similar to that of Douv. Martini.

Similarities and differences. The species is close on the one hand to Douv. Martini, and on the other to Douv. Stuckenbergі and pusillum. From the first it differs in less thick whorls, less strongly developed tubercles, and, correspondingly, a different form of the cross-section of the whorls and of the umbilicus. From Douv. Stuckenbergі it differs in a weaker sculpture and, correspondingly, a more rounded cross-section of the whorls. From Douv. pusillum it differs in much more strongly developed tubercles and thicker and sharper ribs. Douv. subnodosocostatum Sinzow (Douvilleiceras Arten; S. 175; Taf. II, Fig. 1–8) is much larger than my form, has thicker whorls and stronger tubercles and ribs.

Locality. Khodjal-Makhi (14 specimens); judging by preservation, probably from Aptian concretions.

42. Douvilleiceras subnodosocostatum Sinzow. 1906.

1. Douvilleiceras subnodosocostatum. Sinzow. Douvilleiceras—Arten; S. 175; Taf. II. Fig. 1–8.

2. Douvilleiceras subnodosocostatum. Jacob. Engelberger Aa. p. 14; pl. I, fig. 4–6.

To this species I assign only one small specimen with fairly strong main ribs, noticeable intermediate ribs, noticeable umbonal and siphonal tubercles, and well-developed lateral tubercles.

Similarities and differences. According to Prof. Sinzow, this species differs from Douv. Martini in thicker main ribs and in the presence of a third pair of tubercles. With regard to the latter character I must say that this third pair of tubercles (umbonal—

tubercles) is also observed in Douv. Martini on some ribs. The most difficult distinction is between Douv. subnodosocostatum and Stuckenbergii. Their differences have already been given by me under the latter form; here I shall note only that in Douv. subnodosocostatum the intermediate ribs are nevertheless somewhat more distinctly developed than in Douv. Stuckenbergii.

Locality. Lavashi: gray sandy marl No. 1 (1 specimen).

Distribution. The species was described by Prof. Sinzov from Mangyshlak and from the environs of Kislovodsk.

Jacob cites it from the upper Aptian of Switzerland.

43. Douvilleiceras Waageni Anthula sp. 1899.

1. Pachydiscus (?) Waageni. Anthula. Kreidefossilien v. Kaukasus: S. 106; Taf. IX, Fig. 1.

2. Douvilleiceras Meyendorffi var. Waageni. Sinzow, Douvilleiceras Arten; S. 164; Taf. I, Fig. 10.

Numerical data.

Specimens	I	II	I	II	I	II
	in millimeters	in millimeters	ratio to shell diameter	ratio to shell diameter	ratio to thickness of corresponding whorl	ratio to thickness of corresponding whorl
Shell diameter	113	160	1.00	1.00	—	—
“ umbilicus	30	—	0.27	—	—	—
Last whorl: height above suture	50	73	0.44	0.46	0.85	0.97
Last whorl: “ “ preceding whorl	43	58	0.38	0.36	0.73	0.77
Last whorl: thickness	59	75	0.52	0.47	1.00	1.00

Although the form under consideration departs somewhat from the type of Anthula, showing in part somewhat higher whorls, I do not consider it necessary to separate it as a new species, since the sculpture is entirely identical with Anthula’s type. I have nothing essential to add to Anthula’s description of the species.

Similarities and differences. Its belonging to the genus Douvilleiceras is undoubtedly proved by the sculpture of the young whorls and by the structure of the suture line, which is typically similar to the suture line of Douv. Martini. Prof. Sinzov regards Anthula’s species as a variety of Douv. Meyendorffi d’Orb. sp. I prefer to preserve the spe—

double name Anthula, because the young whorls of my specimens show a weaker development of the intermediate ribs than in Douv. Meyendorffi, and in their general appearance somewhat recall Douv. Martini. In addition, on the young whorls there are in part fairly distinct siphonal tubercles.

Locality. Khodzhal-Makha (2 specimens and 3 fragments) from concretions in Aptian clay no. 10; Tsudakhar, in clay no. 19–11 (2 fragments).

Distribution. Originally described from Dagestan itself (Ashilta); besides this, known from Mangyshlak.

44. Douvilleiceras aff. Meyendorffi D’Orbigny sp. 1844.

(plate III, fig. ?9).

1. Ammonites Meyendorffi. D’Orbigny. Paléontologie de la Russie; p. 428; pl. XXXII, fig. 4—5.
2. Ammonites Cornuelianus. Sinzow. On the Jurassic and Cretaceous petrifactions of Saratov Province; p. 30; pl. V, fig. 1.
3. Douvilleiceras Meyendorffi. Sinzow. Douvilleiceras—Arten; S. 161; Taf. I, Fig. 7—9.

A form very close to Douv. Waageni and differing from the latter only in its coarser ribbing and in the better development of the siphonal tubercles on the young whorls. The same differences are cited by Prof. Sinzow for Douv. Meyendorffi d’Orbigny sp. However, a careful comparison with d’Orbigny’s figure shows that in Amm. Meyendorffi the intermediate ribs are more strongly developed and the whorls thicker than in the form under consideration. The same differences are also noticeable when compared with the illustrations of Prof. Sinzow. These characters bring the form under consideration closer to Douv. Waageni, and I would not separate it from the latter were it not for the danger of confusion with Douv. Meyendorffi.

Numerical data.

		in millimeters	Ratio to shell diameter	Ratio to thickness of corresponding whorl
	Shell diameter	101	1.00	—
	“ umbilicus	29	0.29	—
Last whorl	Height above the suture	45	0.45	0.88
Last whorl	“ “ previous whorl	38	0.38	0.75
Last whorl	Thickness	51	0.50	1.00

Locality. Khodzhal-Makha (1 specimen), from concretions in Aptian clay No. 10.

Distribution. Douv. Meyendorffi has been described from near Saratov.

45. Douvilleiceras Cornuelianum. D’Orbigny. 1840.

(Plate III, figs. 40–41).

1. Ammonites Cornuelianus. D’Orbigny. Terr. Crét. I; p. 364; pl. 112, figs. 1–2; pl. 58, fig. 9 (under the name Amm. Martini).

2. Ammonites Cornuelianus. Forbes. Lower Greensand Fossils; p. 354.

3. Ammonites Cornuelianus. D’Orbigny. Prodrome II; p. 113; ét. 18 Aptien No. 18.

4. Ammonites Cornuelianus. Pictet et Renevier. Perte du Rhône. p. 21.

5. Ammonites Cornuelianus. Pictet et Campiche. Sainte Croix; p. 336.

6. Acanthoceras Martini (pars). Neumayr und Uhlig. Hilsammonitiden; S. 180.

7. Acanthoceras Cornueli. Kilian. Montagne de Lure II; p. 10.

8. Acanthoceras (Douvilleiceras) Martini (pars). Anthula. Kreidefossilien v. Kaukasus; s. 122.

9. Acanthoceras Martini (pars). V. Koenen. Neocomammonitiden s. 403.

10. Douvilleiceras Cornuelianum. Sinzow. Douvilleiceras—Arten; s. 158; Taf. I, Fig. 1–2.

Since 1881 this species has usually been combined with Douv. Martini. Kilian (l. c.) as early as 1888 spoke in favor of its independence. Prof. Sinzow has recently shown the possibility of a quite clear separation of the two species, and in my understanding of this species I follow him. My material is fairly abundant, but its preservation leaves much to be desired, and therefore I do not give a new description of this species.

Similarities and differences. The distinguishing features from Douv. Martini have been indicated by Prof. Sinzow (l. c.). For my part I can only add that the siphonal tubercles of elongate form are sometimes quite clearly developed on the young whorls, and that the intermediate ribs are always developed much better than in Douv. Martini. Less clear, in my opinion, are the relations of the species under consideration to Douv. Meyendorffi. This latter form, apparently, from *Douv. Waa-

geni, with which Prof. Sinzow unites it into a single species, differs more sharply than from Douv. Cornuelianum.

Locality. Lavashi, in gray sandy marl no. 1 (25 specimens and fragments), no. 5 (1 fragment); Khodzhal-Makhi, from similar rock (1 fragment); Tsudakhar, in gray sandy marl no. 4 b (2 fragments); Shakh-Dag, in gray sandy marl (1 fragment).

Distribution. The species is regarded as Aptian, and is cited from both the Upper and the Lower Aptian.

Its geographical distribution is probably broad, but its clarification is difficult owing to the confusion, prevalent since 1881, with Douv. Martini. With the greatest certainty one may indicate its occurrence in England, northern Germany, France, Switzerland, Spain, in the Caucasus and Mangyshlak.

46. Douvilleiceras seminodosum Sinzow. 1906.

(Pl. III. Figs. 42–43)

1. Douvilleiceras seminodosum. Sinzow. Douvilleiceras—Arten; S. 165; Taf. I, Fig. 3—6.

2. Douvilleiceras seminodosum. Kilian. Lethaea geognostica; s. 283.

My fairly abundant material is predominantly fragmentary in character, and on the basis of it I do not venture to give a new description of this species, which, in my opinion, is truly important.

Similarities and differences. This species differs from Douv. Cornuelianum by a higher cross-section, weaker and irregular tubercles, and thinner ribs, often irregularly branched. Kilian (l. c.) asserts that Douv. seminodosum is identical with Douv. Stobiecki d’Orb. sp. 1850 (Prodrome II; p. 113; ét. 18 Aptien no. 15). Kilian’s older description (Acanthoceras Stobieckii. Montagne de Lure II; p. 12) speaks rather against such a view—at least if he is not referring there to considerably larger specimens. The identity of my specimens with Prof. Sinzow’s species seems undoubted.

Locality. Lavashi, in gray sandy marl (15 fragments); Khodzhal-Makhi, from similar marl (1 fragment) and from similar marl no. 11 (1 fragment); Tsudakhar, in gray sandy marl no. 4 b (4 fragments); doubtful fragments from Kuli (1 fragment) and Lavashei, from marl no. 4 (2 fragments).

Distribution. The species is generally regarded as Aptian. Douv. Stobiecki chiefly as Lower Aptian.

The geographical distribution cannot be characterized precisely, owing to confusion with Douv. Cornuelianum and the uncertainty of the meaning of the forms cited as Douv. Stobieckii. Its distribution in Mangyshlak and the Caucasus is beyond doubt; probably also in France.

47. Douvilleiceras cf. Albrechti Austriae Hohenegger sp. 1883.

1. Acanthoceras Albrechti Austriae. V. Koenen, Neocomammonitiden; S. 405; Taf. XLI, fig. 1.

2. Douvilleiceras Albrechti Austriae. Sinzow. Douvilleiceras-Arten; S. 167; Taf. IV, fig. 1—2.

3. Douvilleiceras Albrechti Austriae. Krenkel. Delagoa Bai; S. 147.

4. Douvilleiceras Albrechti Austriae. Kilian. Lethaea geognostica; Taf. 8, Fig. 2.

For the synonymy, see the cited works. The crushed specimen shows a close resemblance to this species. The ribs are somewhat more sharply defined than as figured by Prof. Sinzow in a specimen of generally corresponding dimensions. The species is in urgent need of a new description.

Locality. Lavashi; collected by A. Stuckenberg; the exact locality is unknown; rock—gray sandy marl.

Distribution. Douv. Albrechti Austriae is regarded as a Barremian and Lower Aptian form.

Geographical distribution: Carpathians, France, northern Germany, Spain, Romania, Caucasus, eastern Africa.

48. Douvilleiceras sp. ind. 1.

(Plate III, fig. 44).

A deformed fragmentary specimen. The young whorls show similarity to Douv. Cornuelianum, but on the living chamber all the ribs are equal, rather thin and sharp, separated by wide intervals, and bear only barely noticeable lateral and almost imperceptible umbilical tubercles. This stage is reached already at a diameter of about 35 mm. There is some external resemblance to Douv. Buxtorfi Jacob et Tobler (Engelberg. Aa; p. 15; pl. I, fig. 9—10).

Locality. Lavashi, in gray sandy marl No. 1.

49. Douvilleiceras sp. ind. 2.

(Plate III, fig. 45.).

A fragment resembling Douv. seminodosum, but with coarser ribbing.

Locality. Tsudakhar, in the gray sandy marl no. 4 b.

50. Douvilleiceras sp. ind. 3.

(Plate III, fig. 46).

Fragments of a form from the group of Douv. Cornuelianum, with thick lower whorls. The principal ribs differ more sharply in size from the intermediate ones than in Douv. Cornuelianum and seminodosum, and they bear rather strong lateral tubercles, less thick than in Douv. Cornuelianum and stronger than in Douv. seminodosum. The umbilical tubercles are clear only in part. Its relation to Douv. Meyendorffi is not clear to me, but the possibility of identity is not excluded.

Locality. Lavashi, in the gray sandy marl no. 1 (2 specimens).

Genus Acanthohoplites Sinzow. 1907.

The type of the genus established by Prof. Sinzow is Acanthohoplites Aschiltaensis Anthula sp. 1899 (see below).

In his genus Parahoplites, Anthula (Kreidefoss. v. Kaukasus; pp. 109–112) distinguished two groups. One group, lacking tubercles in youth, was typical of the genus, and Parahoplites Melchioris Anthula was to be chosen as its type. The other group, characterized by the presence of tubercles on the young whorls, was the group Parahoplites Aschiltaensis Anthula. At the same time, this principal distinguishing character of the two groups, as Anthula himself indicated, by no means had absolute significance. Par. Treffryanus Karsten sp., Par. Uhligi Anthula, according to Anthula himself, have tubercles in youth; to these two species one may add several more forms with similar tubercles from the group of Par. Melchioris.

Jacob in 1905 (Clausages; pp. 406–408) narrowed the concept of the genus Parahoplites, leaving this generic name only for the group Par. Melchioris, while this author assigned the group Par. Aschiltaensis to the old genus Douvilleiceras. Jacob maintained the same point of view also in 1907 (Ammonites du Crétacé moyen; p. 46). Prof. Sinzow, in the same year 1907, proposed for the group Par. Aschiltaensis the new generic name Acanthohoplites, and he transferred into this new genus also some species from the group Par. Melchioris. In my opinion, the separation of the group Par. Aschiltaensis from the genus Douvilleiceras has its grounds. In general appearance the representatives of the two genera are rather sharply different. Siphonal tubercles and weakening of the sculpture in the middle of the siphonal side—phenomena usual in Douv-

villeiceras and almost entirely absent in Acanthohoplites. The lobate line is also different, since representatives of Acanthohoplites have a much higher first lateral saddle. Even in cases of convergence of characters in large forms (Douv. Waageni Anthula), species of Douvilleiceras retain thicker whorls and a characteristically small first lateral saddle. The separation of Acanthohoplites from Parahoplites is somewhat less well justified. Parahoplites Melchioris is, in general, a rather aberrant form among the species assigned by Anthula to Parahoplites. The simple and broad lobes and saddles, the tongue-shaped bend of the ribs on the siphonal side, and the weakness of the sculpture on the young whorls sharply distinguish Parah. Melchioris from the other species assigned by Anthula to the same group. Consequently, if in understanding the genus Parahoplites one proceeds from the single species Par. Melchioris, accepted by the author of the genus as the type, then the species referred by Prof. Sinzow to Acanthohoplites will, in general, differ rather sharply from Par. Melchioris and may constitute a quite natural, at least at first glance, new genus. If, however, the entire group of Par. Melchioris in Anthula is taken as the basis for understanding the genus Parahoplites, then Acanthohoplites Sinzow merges completely with the genus Parahoplites. The distinguishing characters indicated by Prof. Sinzow (Ammonites v. Mangyschlak, pp. 455–458) ultimately reduce to the tuberculation of the young whorls and the lesser asymmetry of the first lateral lobe in Acanthohoplites. In relation to Par. Melchioris these characters (except for the asymmetry of the first lateral lobe) are indeed significant; the first lateral lobe in Par. Melchioris is not always very asymmetrical, but it is nevertheless broader and blunter than in species of Acanthohoplites. But all, or at least almost all, the remaining species of the group cited by Anthula will then pass over to Acanthohoplites. Since the origin of Par. Melchioris has not yet essentially been clarified, and its connection with representatives of Acanthohoplites is, in my opinion, doubtful, I retain Prof. Sinzow’s generic name in the author’s sense.

51. Acanthohoplites Aschiltaensis Anthula sp. 1899.
(Pl. III, fig. 47).

1. Acanthoceras Aschiltaense. Anthula. Kreidefossilien v. Kaukasus; S. 117; Taf. X, fig. 2—3 (4?); (non Taf. XI, Fig. 1).

2. Acanthohoplites Aschiltaensis. Sinzow. Ammonitiden v. Mangyschlak; S. 479; Taf. V, fig. 1—8; Taf. VI Fig. 19—21.

3. Parahoplites cf. Aschiltaensis. Sommermeier. Aptien und Albien v. Peru; S. 379.

The description of the species in Anthula contains certain contradictions. Anthula says that, with a shell diameter of about 70 mm, the last whorl bears 45 sharp falcate ribs, of which 20 principal ones have tubercles; the remaining ribs are intermediate and are inserted, 3, more rarely 2, between the principal ribs; in that case the total number of ribs should be at least \(19 \times 3 + 1\), i.e. 58, and not 45, as stated by Anthula. In fact, in Taf. X, Fig. 2 in Anthula, the specimen of about 70 mm in diameter bears only 1, more rarely 2, intermediate ribs in each interval between the principal ribs, and some intervals bear no intermediate ribs at all. Taf. X, Fig. 3 in Anthula depicts a smaller specimen, which indeed has 2–3 intermediate ribs between the principal ones. But here the number of principal ribs is only 11. Taf. XI, Fig. 1 in Anthula apparently depicts already another form, having, at 60 mm diameter, only one intermediate rib between the principal ones and weaker tubercles. Taf. X, Fig. 4 does not allow one to decide to which of the two mentioned forms it belongs. Among the figures of Prof. Sinzow, pl. V, figs. 1, 4, and 5 show too weak a development of the principal ribs on the young whorls for Acanth. Aschiltaensis, and their assignment to this species seems to me somewhat doubtful. My two specimens correspond fairly exactly to Taf. X, Figs. 2–3 in Anthula and to Taf. VI, Figs. 19–21 in Prof. Sinzow.

Occurrence. Khodzhal-Makha (2 specimens), judging by preservation, from concretions in Aptian clay.

Distribution. I regard this species as Aptian. It has hitherto been recorded from the Caucasus, Mangyshlak, Tunisia, Peru, and Mexico. Kilian (Lethaea geognostica, p. 283) also records it from the Lower Aptian of southeastern France.

52. Acanthohoplites laticostatus. Sinzow. 1907.

1. Acanthohopolites laticostatus. Sinzow. Ammonitiden v. Mangyschlak; p. 482; Taf. V, Fig. 9–13.

One specimen, differing from Acanth. Aschiltaensis by ribs widened on the siphonal side, a flatter siphonal side, and a broader umbilicus. A new description of the species is highly desirable, but I have at my disposal only a single specimen, and that one too fragmentary for such a description.

Occurrence. Tsudakhar in gray sandy marl No. 4 b. (1 specimen).

Distribution. The species is so far known only from the Caucasus and Mangyshlak.

53. Acanthohoplites aplanatus (Sinzow 1907) n. sp.

(Pl. III, fig. 48).

1. Acanthohoplites Aschiltaensis var. aplanata. Sinzow. Ammonitiden v. Mangyschlak; p. 481; Taf. V, Fig. 4—7.

Numerical data

Specimens	I	II	I	II	I	II
Specimens	In millimetres	In millimetres	Ratio to shell diameter	Ratio to shell diameter	Ratio to thickness of corresponding whorl	Ratio to thickness of corresponding whorl
Shell diameter	38	48	1.00	1.00	—	—
Umbilicus	11	12	0.29	0.25	—	—
Last whorl: height above the suture	16	22	0.42	0.46	1.14	1.29
Last whorl: height above the preceding whorl	—	15	—	0.31	—	0.88
Last whorl: thickness	14	17	0.37	0.35	1.00	1.00
Penultimate whorl: height above the suture	9	10	0.24	0.21	0.90	1.00
Penultimate whorl: thickness	10	10	0.26	0.21	1.00	1.00

A discoidal shell with a rather narrow umbilicus and fairly high, rather involute whorls. The transverse section of the whorls is high, with a slightly flattened and narrowed siphonal side and weakly convex flanks. The umbilical side descends rather gently. The sculpture consists of 14 main ribs and about 30 intermediate ribs. On young whorls (up to 30 mm in diameter) the main ribs are considerably stronger than the intermediate ones and bear, in the middle of the whorls, lateral tubercles of a spinose character. Umbilical tubercles are sometimes noticeable, but are always indistinct. Later, the main and intermediate ribs become almost equal in strength, and the intermediate ribs differ only in that they do not reach the umbilical side. The intermediate ribs are for the most part intercalated, but in part arise from the branching of the main ribs at the lateral tubercles. Branching of the main ribs on the more adult, non-tuberculate part of the shell is observed only as an exception. The number of intermediate ribs is 2, more rarely 3 per interval; on more adult whorls there are 3—4 and even more per

interval on the young whorls. There are constrictions. The lobe line is similar to that of Acanth. Aschiltaensis.

Similarities and differences. The closest similarity is shown with Acanth. Aschiltaensis, but it differs in a somewhat greater number of intermediate ribs, higher whorls, and a flatter siphonal side. From Acanth. laticostatus it differs in finer ribs and a narrower umbilicus, and also in higher whorls. I prefer to regard this form as a distinct species, and not as a variety, because, while in general approaching more closely Acanth. Aschiltaensis, by the flattening of the siphonal side it recalls Acanth. laticostatus; and, if the latter two forms are separated, then consistency requires the separation also of Acanth. aplanatus.

Locality. Khodzhal’-Makha (2 specimens), probably from concretions in Aptian clay.

Distribution. Apart from this, it is known only from Mangyshlak.

54. Acanthonoplites Tobleri Jacob. sp. 1906.

(Plate III, figs. 49–50).

1. Parahoplites Tobleri. Jacob et Tobler; Engelberg. Aa; p. 11; pl. II, Fig. 4–6.

2. Acanthohoplites Tobleri Sinzow. Ammonitiden v. Mangyschlak; S. 486; Taf. V, Fig. 14–15.

The identification of my specimens with this species is based on comparison with the data of Prof. Sinzow. With his figures my specimens show a very satisfactory resemblance, but in Prof. Sinzow’s description the circumstance is insufficiently emphasized that the ribs in this form, on the siphonal side, have a flat upper surface. This feature, shared by the form under consideration with Acanth. crassicostatus d’Orb. sp., Acanth. peltoceroides Pavl. sp., Acanth. subpeltoceroides Sinz., Acanth. Treffryanus, in Anthula gives the shell a very characteristic appearance, sharply distinguishing it from Acanth. Aschiltaensis, laticostatus, aplanatus, and related forms. The identity of my specimens with Acanth. Tobleri Jacob sp. is somewhat doubtful to me, since, judging from the figures, the French form has a somewhat greater number of main ribs (25–30 as against 20–24 in the Caucasian form). I nevertheless do not venture to separate the Caucasian form as a distinct species, since the number of main ribs is still variable, and the question of the form of the ribs, which is here the most important, was not made sufficiently clear by either of the cited authors. I give, in addition, numerical data relating to my specimens. All the figures are taken from two specimens, which were broken and therefore made it possible to measure the young whorls.

Numerical data.

Specimens	I	II	II	I	II	I	I	II	II	I	II	I	I	II	II	I	II	I
	In millimeters	In millimeters	In millimeters	In millimeters	In millimeters	In millimeters	Ratio to shell diameter	Ratio to shell diameter	Ratio to shell diameter	Ratio to shell diameter	Ratio to shell diameter	Ratio to shell diameter	Ratio to thickness of corresponding whorl	Ratio to thickness of corresponding whorl	Ratio to thickness of corresponding whorl	Ratio to thickness of corresponding whorl	Ratio to thickness of corresponding whorl	Ratio to thickness of corresponding whorl
Shell diameter	45	49	62	66	72	76	1·00	1·00	1·00	1·00	1·00	1·00	—	—	—	—	—	—
Diameter of the umbilicus	13·5	18	24	19	28	24	0·30	0·37	0·39	0·29	0·39	0·32	—	—	—	—	—	—
Last whorl.
Height above the suture	21	20	25	29	28	31	0·47	0·41	0·40	0·44	0·40	0·41	1·11	1·11	1·14	1·32	1·17	1·24
Height above the preceding whorl	17	17	22	24	24	26	0·38	0·35	0·35	0·36	0·35	0·34	0·89	0·94	1·00	1·09	1·00	1·04
Thickness	19	18	22	22	24	25	0·42	0·37	0·35	0·33	0·35	0·33	1·00	1·00	1·00	1·00	1·00	1·00
Penultimate whorl.
Height above the suture	8	8	10	13	14	14	0·18	0·76	0·76	0·20	0·76	0·18	0·73	0·73	0·67	0·95	0·88	1·00
Thickness	11	11	15	14	16	14	0·24	0·22	0·24	0·21	0·24	0·18	1·00	1·00	1·00	1·00	1·00	1·00

As is evident from these figures, the form shows rather sharp differences in the width of the umbilicus. This difference, at least in part, depends on preservation (slight deformation). In addition, it is evident from them that the whorls in the form under consideration are slightly higher than in Acanth. Tobleri of Jacob. Prof. Sinzov’s illustrations show rather somewhat higher whorls than do my specimens.

Locality. Khodjal-Makha (2 specimens), judging by their preservation from concretions in Aptian clay.

Distribution. Reported from the Upper Aptian deposits of southern France, Switzerland, and from the Caucasus.

55. Acanthohoplites n. f. cf. Tobleri Jacob. sp. 1906.

(Table IV, fig. 59)

Numerical data (all measured on 1 specimen).

	In millimeters	In millimeters	In millimeters	Ratio to shell diameter	Ratio to shell diameter	Ratio to shell diameter	Ratio to height of corresponding whorl	Ratio to height of corresponding whorl	Ratio to height of corresponding whorl
Shell diameter	35	79	157	1·00	1·00	1·00	—	—	—
Diameter of the umbilicus	11	25	56	0·31	0·32	0·36	—	—	—
Last whorl.
Height above the suture	18	33	58	0·51	0·42	0·37	1·20	1·27	1·41
Height above the preceding whorl	13	26	46	0·37	0·33	0·29	0·80	1·00	1·12
Thickness	15	26	41	0·43	0·33	0·26	1·00	1·00	1·00
Penultimate whorl.
Height above the suture	8	18	33	0·23	0·23	0·21	0·90	1·20	1·2[[unclear: final digit obscured]]
Thickness	9	15	26	0·26	0·19	0·17	1·00	1·00	1·00

A discoidal shell with a shallow umbilicus and high whorls, involute almost to \(1/2\). The transverse section of the whorls is high, with weakly convex flanks and a sharply rounded siphonal side. The umbilical side is rather gently sloping. The sculpture consists of thick, slightly falciform ribs. The main ribs on the adult whorls number 25–30, are slightly swollen near the umbilical margin, and are somewhat thickened on the siphonal side. The intermediate ribs are intercalated; there is almost always one of them per interval. On the young whorls the ribs on the siphonal side have a flat upper surface, as in Acanth. Tobleri. The lobate line is unknown.

Similarities and differences. The young whorls are almost identical with Asanth. Tobleri. It is therefore not impossible that the form under consideration is the hitherto unknown adult state of Acanth. Tobleri.

Locality. Khodjal-Makhi (1 specimen), judging from its preservation, from concretions in Aptian clay.

56. Acanthohoplites subpeltoceroides. Sinzow 1907.

1. Parahoplites Treffryanus. Anthula, Kreidefossilien v. Kaukasus, S. 115; Taf. VIII, fig. 6.

2. Acanthohoplites subpeltoceroides. Sinzow. Ammonitiden v. Mangyschlak, S. 484; Taf. IV, Fig. 3–4; Taf. V, Fig. 16.

Two small specimens, corresponding to the descriptions and figures in Anthula and Prof. Sinzow. As to their relation to Amm. Treffryanus Karsten, I find it difficult to say anything definite. The flat upper side of the ribs on the siphonal side is characteristic of several species of Acanthohoplites. Sommermeier (Aptien und Albien v. Peru, S. 378) notes that Parahoplites Treffryanus, figured by Anthula, has smooth, angular (glatteckige) ribs, whereas Amm. Treffryanus Karst. shows flatly convex (flachwulstige) ribs. If that of which Sommermeier speaks is indeed Amm. Treffryanus, then obviously the Caucasian form described under this name represents a distinct species.

Similarities and differences. From Acanth. Tobleri in the young stage, my specimens differ by somewhat higher whorls and greater density of ribbing, especially on the siphonal side.

Locality. Khodjal-Makhi (2 specimens), probably from concretions in Aptian clay.

Distribution. Known from the Caucasus and Mangyshlak.

57. Acanthohoplites Sinzowi, n. sp.

(Plate III, figs. 52–55).

1. Acanthohoplites Tobleri var. discoidalis. Sinzow. Ammonitiden v. Mangyschlak; p. 487; pl. V, figs. 17–20.

Specimens	I	II	III	IV	V	VI	VII	VIII	I	II	III	IV	V	VI	VII	VIII	I	II	III	IV	V	VI	VII	VIII	I	II	III	IV	V	VI	VII	VIII
	In millimeters	In millimeters	In millimeters	In millimeters	In millimeters	In millimeters	In millimeters	In millimeters	Numerical data: ratio to shell diameter	Numerical data: ratio to shell diameter	Numerical data: ratio to shell diameter	Numerical data: ratio to shell diameter	Numerical data: ratio to shell diameter	Numerical data: ratio to shell diameter	Numerical data: ratio to shell diameter	Numerical data: ratio to shell diameter	Ratio to umbilical diameter	Ratio to umbilical diameter	Ratio to umbilical diameter	Ratio to umbilical diameter	Ratio to umbilical diameter	Ratio to umbilical diameter	Ratio to umbilical diameter	Ratio to umbilical diameter	Ratio of thickness to thickness of preceding whorl	Ratio of thickness to thickness of preceding whorl	Ratio of thickness to thickness of preceding whorl	Ratio of thickness to thickness of preceding whorl	Ratio of thickness to thickness of preceding whorl	Ratio of thickness to thickness of preceding whorl	Ratio of thickness to thickness of preceding whorl	Ratio of thickness to thickness of preceding whorl
Diameter of shell	17	21	22	22	22	23	30	32	1.00	1.00	1.00	1.00	1.00	1.00	1.00	1.00	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—
Diameter of umbilicus	6	6	7	7	7	8	11	10	0.35	0.29	0.32	0.32	0.35	0.37	0.31	0.33	1.00	1.00	1.00	1.00	1.00	1.00	1.00	1.00	—	—	—	—	—	—	—	—
Last whorl: height at suture	7	9	9	9	10	12	14	[[unclear: value]]	0.41	0.43	0.41	0.45	0.43	0.40	0.44	0.40	1.00	1.50	1.28	1.13	1.11	1.09	1.17	1.28	—	—	—	—	—	—	—	—
Last whorl: before aperture	6	8	8	8	8	—	11	[[unclear: value]]	0.35	0.38	0.36	0.36	0.39	—	0.34	0.33	1.00	1.33	1.00	1.00	1.00	—	0.91	1.06	—	—	—	—	—	—	—	—
Last whorl: thickness	7	9	8	9	9	11	12	[[unclear: value]]	0.41	0.43	0.36	0.41	0.39	0.37	0.38	0.31	1.00	1.50	1.13	1.11	1.00	1.00	1.00	1.00	—	—	—	—	—	—	—	—
Penultimate whorl: height at suture	3	4	5	5	6	7	7	[[unclear: value]]	0.18	0.19	0.23	0.27	0.22	0.23	0.22	0.21	0.43	0.23	0.70	0.70	0.22	0.23	0.22	0.21	0.75	0.80	0.83	1.00	0.83	1.00	0.88	1.09
Penultimate whorl: thickness	4	5	6	6	6	7	7	[[unclear: value]]	0.24	0.24	0.27	0.27	0.26	0.27	0.25	0.19	0.57	0.55	0.86	0.70	0.26	0.27	0.25	0.19	1.00	1.00	1.00	1.00	1.00	1.00	1.00	1.00

Discoidal shell with rather high and relatively slowly growing whorls, occupying about \(1/3\) of the diameter of the umbilicus. The cross-section of the whorls is elliptical; the umbilical side is rather flat.

The sculpture consists of rather strong falciform ribs. The main ribs, numbering about 16 at the umbilicus, are sharp and crest-like, raised so that a semblance of elongated umbilical tubercles is formed. On the siphonal side they are thickened and, on the young whorls and on the greater part of the adult ones, have a flat upper side. Toward the end of the shell the adult individuals have ribs with a convex and even crest-like upper side on the siphonal side of the shell. The intermediate ribs are intercalated; their number is 1 per interspace. On the siphonal side the intermediate ribs are similar to the main ones. The lobe line is typically similar to that of Acanth. Aschiltaensis. The young whorls are somewhat thicker than the adult ones. Up to 20 mm shell diameter they bear lateral tubercles. The main ribs branch from these tubercles; the number of main ribs falls to 9–10; the number of intermediate ribs reaches 2 and 3 per interspace.

Similarities and differences. A species extremely close to Acanth. Tobleri, but differing from the latter in its higher whorls and smaller size. In Acanth. Sinzowi the change in sculpture characteristic of the end of the adult living chamber, expressed in the appearance of sparse, sharply falciform ribs not flat above on the siphonal side, occurs already at a shell diameter of 57 mm. In Acanth. Tobleri no such change is observed up to 70 mm. In addition, in Acanth. Tobleri the ribs on the siphonal side in general are already, even on the young whorls, the main ribs bearing tubercles, and the ribs are less sharply differentiated from the intermediate ones.

Locality. Khodzhal-Makha (16 specimens), judging by preservation from concretions of Aptian clay; Khodzhal-Makha, from a fragment of such a concretion No. 8 (12 fragments); Khodzhal-Makha, from concretions in Aptian clay No. 10 (3 fragments); Gunib (1 fragment).

58. Acanthohoplites sub-Tobleri n. sp.

(pl. III, figs. 51, 56–58).

Specimens	In millimeters I	In millimeters II	In millimeters III	In millimeters IV	In millimeters V	In millimeters VI	In millimeters VII	Numerical data: ratio to shell diameter I	Ratio to diameter II	Ratio to diameter III	Ratio to diameter IV	Ratio to diameter V	Ratio to diameter VI	Ratio to diameter VII	Ratio to thickness of last whorl I	Ratio to thickness II	Ratio to thickness III	Ratio to thickness IV	Ratio to thickness V	Ratio to thickness VI	Ratio to thickness VII
Shell diameter	17	25	27	33	34	35	36	1.00	1.00	1.00	1.00	1.00	1.00	1.00	—	—	—	—	1.15	—	1.00
Umbilicus	5	8	7	10	10	11	11	0.29	0.32	0.26	0.30	0.29	0.31	0.31	—	—	—	—	—	—	—
Last whorl: height at the suture	7	10	12	14	15	14	15	0.41	0.40	0.44	0.40	0.44	0.40	0.42	0.88	1.11	1.09	1.17	1.25	1.17	1.15
Last whorl: preceding whorl	—	—	10	12	11	—	—	0.35	—	—	0.30	0.35	0.31	—	0.75	—	—	0.83	1.00	1.00	—
Last whorl: thickness	8	9	11	12	12	11	13	0.47	0.36	0.41	0.36	0.35	0.31	0.36	1.00	1.00	1.00	1.00	1.00	1.00	1.00
Penultimate whorl: height at the suture	4	6	7	8	8	8	8	0.24	0.24	0.26	0.24	0.24	0.23	0.22	0.80	1.00	1.00	1.14	1.00	1.00	1.00
Penultimate whorl: thickness	5	6	7	7	8	8	8	0.29	0.24	0.26	0.21	0.24	0.23	0.22	1.00	1.00	1.00	1.00	1.00	1.00	1.00

A discoid shell with rather high whorls, with an umbilicus occupying somewhat less than \(1/3\) of the diameter. The transverse section

the whorl section is elliptical, the umbilical side rather steep. The sculpture consists of slightly falciform ribs. The main ribs, about 20–25 in number, on the contrary, begin near the umbilicus and run weakly falciformly toward the siphonal side. On the siphonal side they are somewhat thickened and have a flat upper surface. The intermediate ribs are intercalated, one in each interval. On the siphonal side they are similar to the main ribs.

The suture line is typically similar to that of Acanth. Aschiltaensis. The young whorls are thicker than the adult ones. Up to 20 mm in diameter they bear small lateral tubercles. The main ribs branch at these tubercles. The number of intermediate ribs is usually 2 per interval.

Similarities and differences. This species may be compared with Acanth. Tobleri, Sinzowi and subpeltoceroides. From Acanth. Tobleri it differs in having higher whorls and denser ribbing. From Acanth. Sinzowi it differs in denser ribbing, a somewhat narrower and steeper umbilicus, and less strong tubercles on the young whorls. From Acanth. subpeltoceroides it differs in having thinner ribs, especially thin on the siphonal side.

Locality. Khadzhal-Makha (32 specimens), probably from Aptian concretions in clay; Khodzhal-Makha, from a fragment of such a concretion No. 8 (1 specimen); Khadzhal-Makha, from gray sandy marl No. 11 (3 fragments); Kaka-Makha (1 fragment); Lavashi, in gray sandy marl (2 fragments).

59. Acanthohoplites planidorsatus n. sp.

(plate IV, figs. 60—61).

Numerical data.

	In millimeters	Ratio to shell diameter	Ratio to thickness of corresponding whorl
Diameter of shell	38	1.00	—
Diameter of umbilicus	13	0.34	—
Last whorl.
Height above suture	15	0.39	1.25
Height above preceding whorl	12	0.32	1.00
Thickness	12	0.32	1.00
Penultimate whorl.
Height above suture	8	0.21	1.00
Thickness	8	0.21	1.00

A discoidal shell with high whorls and an umbilicus occupying about \(1/3\) of the diameter. The cross-section of the whorls is somewhat angular, owing to the flattened siphonal side and the conspicuous umbilical shoulder. The umbilical wall is rather steep.

The sculpture consists of strong, very slightly sickle-shaped ribs. The main ribs begin at the umbilicus, are noticeably swollen at the umbilical shoulder, and bear well-expressed lateral tubercles above the middle of the flanks, which disappear at a diameter of about 35 mm. The number of main ribs is about 20. On the siphonal side the main ribs are broadened, but do not have a flat upper surface. The intermediate ribs are predominantly intercalated, 1 in each interval. Sometimes they are the result of branching of the main ribs at the lateral tubercles or near the umbilical shoulder. Constrictions are present.

The suture line is of the type of Acanth. Aschiltaensis. The young whorls have strong main ribs with well-developed umbilical and lateral tubercles and fine intermediate ribs, numbering about 4 in each interval.

Similarities and differences. The sculpture of the young whorls is similar to Acanth. Aschiltaensis, but the form described has higher whorls, a flat siphonal side, and, at a diameter of about 35 mm, less sharply differentiated ribs. Acanth. laticostatus has broader ribs and, at a young age, a more rounded siphonal side; moreover, it has no umbilical tubercles and differs in its somewhat thicker whorls. Acanth. aplanatus is much more densely ribbed than the form described, and its tubercles are less developed.

Locality. Khodzhal-Makha (2 specimens), judging by preservation, from concretions of Aptian clay.

60. Acanthohoplites rectangularis n. sp.

(plate IV, figs. 62–63).

	In millimeters	Ratio to shell diameter	Ratio to thickness of corresponding whorl
Diameter of shell	23	1.00	—
Diameter of umbilicus	7	0.30	—
Last whorl.
Height above the suture	10	0.43	1.11
Height above preceding whorl	7	0.30	0.78
Thickness	9	0.39	1.00
Penultimate whorl.
Height above the suture	6	0.26	1.00
Thickness	6	0.26	1.00

A discoid shell with high rectangular whorls and an umbilicus occupying somewhat less than \(1/3\) of the diameter. The cross-section of the whorls is rounded-rectangular; the umbilical wall is fairly steep.

The sculpture consists of almost straight ribs. The main ribs, about 13 in number, become stronger on the siphonal side, and some of them have, on this latter side, a flat upper face; the intermediate ribs, one per interval, are partly intercalated and partly branches of the main ribs, and on the siphonal side they are entirely like the latter.

The suture line is of the type of Acanth. Aschiltaensis.

The young whorls have a thicker and more rounded cross-section, are more densely ribbed, and bear noticeable lateral tubercles on the main ribs.

Similarities and differences. Young specimens somewhat recall Acanth. Sinevii and sub-Tobleri; adults approach more closely Acanth. Abichi. It differs sharply from both species in the rectangular cross-section of the whorls, and from the latter, in addition, in the high whorls and the early disappearance of the tubercles.

Locality. Khodzhal’-Makha (3 specimens), judging by preservation, from concretions of Aptian clay.

61. Acanthohoplites quadratus n. sp.

(Plate IV, fig. 64).

Numerical data.

	In millim.	Ratio to shell diam.	Ratio to thickness of corresponding whorl
Diameter of shell	27	1.00	—
Diameter of umbilicus	9	0.33	—

Last whorl.

	In millim.	Ratio to shell diam.	Ratio to thickness of corresponding whorl
Height above the suture	11	0.41	1.00
Height above the preceding whorl	8	0.30	0.73
Thickness	11	0.41	1.00

Penultimate whorl.

	In millim.	Ratio to shell diam.	Ratio to thickness of corresponding whorl
Height above the suture	6	0.22	0.92
Thickness	6.5	0.24	1.00

A discoidal shell with an umbilicus occupying about \(1/3\) of its diameter, and with rather slowly increasing whorls. The cross-section of the whorls is rounded-quadrate; the umbilical wall is steep.

The sculpture consists of very weakly falciform ribs. The main ribs, about 28 in number, are somewhat unevenly developed and run from the umbilicus toward the siphonal side, strengthening and widening rather gradually. On the siphonal side they acquire a flat upper surface. The intermediate ribs, 1 in number, more rarely 2 in the interval, inserted on the living chamber, on the young whorls are often branches of the main ribs. The branching of these latter on the young whorls takes place in weakly expressed lateral tubercles above the middle of the flanks. At the end of the living chamber the ribs on the siphonal side are arcuately bent forward. The suture line, owing to the conditions of preservation, cannot be shown; in character it recalls Acanth. Aschiltaensis.

Similarities and differences. In the character of its ribbing the species described is closely allied to Acanth. sub-Tobleri, from which, however, it differs in its lower, rounded-quadrate whorls and in the arcuate bending of the ribs on the siphonal side near the end of the living chamber.

Occurrence. Khodzhalt-Makha (1 specimen), judging by its preservation, from concretions of Aptian clay; Kupa (1 specimen).

62. Acanthohoplites Lorioli Sinzow. 1907.

1. Acanthohoplites Lorioli. Sinzow. Ammonitiden v. Mangyschlak; S. 497, Taf. VII, Fig. 10—11.

Numerical data.

Specimens	I (in millimeters)	II (in millimeters)	I (ratio to shell diameter)	II (ratio to shell diameter)	I (ratio to thickness of corresponding whorl)	II (ratio to thickness of corresponding whorl)
Diameter of shell	35	35	1.00	1.00	—	—
Diameter of umbilicus	12	11	0.34	0.31	—	—
Last whorl.
Height above the suture	14	14	0.40	0.40	1.17	1.17
Height above preceding whorl	11	11	0.31	0.31	0.92	0.92
Thickness	12	12	0.34	0.34	1.00	1.00
Penultimate whorl.
Height above the suture	8	7	0.23	0.20	1.00	1.00
Thickness	8	7	0.23	0.20	1.00	1.00

Two specimens, by their size, occupy an intermediate position between the cited figures of Prof. Sinzov. The siphonal side appears somewhat flatter than is seen in the cited figures. In other respects the similarity is quite complete.

Similarities and differences. As Prof. Sinzov partly indicates, this species is close to Acanth. multispinatus Anth. sp.; but, besides the lesser development of the tubercles, it differs from Anthula’s species also in its smaller size. Already at 40 and a few millimeters Acanth. Lorioli reaches its full age, presenting on the living chamber the coarse sculpture characteristic of an adult shell.

Locality. Khodzhal-Makha, probably from concretions in Aptian clay (2 specimens).

Distribution. The species was described from the dark clay of Mangyshlak and the glauconitic sandstone of Pyatigorsk. In my opinion, it is an Aptian form.

63. Acanthohoplites multispinatus Anthula sp. 1899.

1. Parahoplites multispinatus Anthula. Kreidefossilien v. Kaukasus; S. 119, Taf. X, Fig. 5.

2. Acanthohoplites multispinatus. Sinzow. Ammonitiden v. Mangyschlak; S. 492, Taf. VII, Fig. 1—8.

Numerical data.

	In millimeters	Ratio to shell diam.	Ratio to thickness of corresponding whorl
Diameter of shell	68	1·00	—
Diameter of umbilicus	20	0·29	—
Last whorl.
Height above the suture	32	0·47	1·28
Height above the preceding whorl	23	0·34	0·92
Thickness	25	0·37	1·00
Penultimate whorl.
Height above the suture	14	0·21	1·00
Thickness	14	0·21	1·00

Prof. Sinzov refers to this species several specimens that deviate from one another. Variations are observed both in the character of the ribbing (see, for example, the very thick ribs in var. robusta, Sinz., l. c., Fig. 7—8) and in the development of the tubercles. My specimen, by its size, permits comparison only with the data of Prof. Sinzov and undoubtedly belongs to Acanth. multispinatus in the sense of this latter author. Unfortunately, at this size it is impossible to—

one cannot observe sufficiently distinct siphonal tubercles, and for this reason it is impossible to express oneself with certainty regarding the relationship of the forms united by Prof. Sinzov under the name Acanth. multispinatus to the form originally described under this name. Apparently, Acanth. multispinatus Anthul sp. is part of Acanth. multispinatus in the sense of Prof. Sinzov. While considering a subdivision of the species desirable, I do not have at my disposal material sufficient for such an operation.

Locality. Khodzhal-Makhi (1 specimen), probably from concretions in Aptian clay.

Distribution. Known from the Caucasus and from Mangyshlak. In my opinion, the species is Aptian.

64. Acanthohoplites Abichi. Anthula. sp. 1899.

1. Parahoplites Abichi. Anthula, Kreidefossilien v Kaukasus; S. Taf. IX, Fig. 2.

2. Acanthohoplites Abichi Sinzow. Ammonitiden v. Mangyschlak, S. 490; Taf. VI, Fig. 1—3.

My rather abundant, but very fragmentary, material shows a direct resemblance to Anthula’s figure, to whose description I have nothing essential to add. Adult specimens similar to that figured and described by Prof. Sinzov are absent from my material.

Locality. Saltinskaya station in gray sandy marl No. 3 (15 fragments); Tsudakhar in gray sandy marl No. 46 (1 fragment).

Distribution. Hitherto cited from the Caucasus and Mangyshlak. The species is, in all probability, Aptian.

65. Acanthohoplites Trautscholdi Sinzowicz, Bacewicz et Sorokin sp. 1876.

1. Acanthohoplites Trautscholdi Sinzow. Ammonitiden v. Mangyschlak, S. 499; Taf. IV, Fig. 9—15.

There, see the synonymy.

The identification of my 4 specimens with this species is based on comparison with the figures in Prof. Sinzov. The indicated figures show certain variations in the transverse section of the whorls of the shell. In this respect my specimens are adjacent to figs. 9—12 in Prof. Sinzov, which show higher whorls. Concerning the identification with Acanthoceras Migneni Seunes,

proposed by Prof. Sinzov, I cannot express myself with certainty, since Seunes’s illustration is not sufficiently clear for such a fine comparison as is needed here. In any case, the similarity of the drawings is very great, and some doubt arises only in view of Seunes’s indication of the closeness of Acanth. Migneni to Ammon. nodosocostatus d’Orbigny.

Locality. Khodzhal-Makha (4 specimens), probably from concretions in Aptian clay.

Distribution. Described from the Caucasus and Mangyshlak. Under the name Ac. Migneni it may also have been described from the Clausage level in France. In view of this it should be regarded, with a broad understanding of the limits of the species, as both an Aptian and an Albian form.

66. Acanthohoplites aff. Trautscholdi Simonowicz, Bocewicz, Sorokin sp. 1876.

(plate IV, fig. 65).

Numerical data.

	In millimeters	Ratio to shell diameter	Ratio to thickness of corresponding whorl
Shell diameter	48	1.00	—
Umbilicus diameter	14	0.29	—
Last whorl.
Height above suture	20	0.42	1.11
Height above preceding whorl	17	0.35	0.94
Thickness	18	0.38	1.00
Penultimate whorl.
Height above suture	10	0.21	1.00
Thickness	10	0.21	1.00

A discoidal shell with a rather narrow umbilicus and high whorls. The cross-section of the whorl approaches a trapezoidal shape, showing a rather flat siphonal side, slightly convex lateral sides converging toward the siphonal side, and a steep umbilical wall. The sculpture consists of 18 main ribs, swollen at the umbilical margin and slightly falciform on the flanks; the intermediate ribs, one to three in each interval, are chiefly intercalated, more rarely branches of the main ribs. On the siphonal side the ribs are rather thin, but some of them, on the younger part of the last whorl, are thickened and bear conspicuous umbilical and lateral, as well as incipient siphonal, tubercles.

The lobate line cannot be studied.

Similarities and differences. In sculpture and in the cross-section of the whorls, the described form comes close to Acanth. Trautscholdi, but on the young part of the last whorl it has sparser and stronger ribs with rudiments of siphonal tubercles and a flatter siphonal side; on the adult part of this whorl, by contrast, the ribs are thinner than in Acanth. Trautscholdi. The appearance of siphonal tubercles and the character of the cross-section also recall Acanth. multispinatus, but the umbilicus in our form is narrower and the ribs thinner. Acanth. Lorioli, at a corresponding size, has thicker ribs. To base a new form on a single specimen, with such confused diagnostics as follows from the comparisons given above, would be risky; therefore I prefer to regard it as aff.

Locality. Khodzhal-Makha (1 specimen), probably from concretions in Aptian clay.

67. Acanthohoplites subangulicostatus (Sinzow 1907) n. sp.

1. Acanthohoplites Trautscholdi var. subangulicostata. Sinzow.
     Ammonitiden v. Mangyschlak; S. 501; Taf. IV, Fig. 16—17.

Since the named form in my material is separated from Acanth. Trautscholdi quite clearly, I consider it more convenient to regard it as an independent species.

Numerical data.

Specimens	I (mm)	II (mm)	III (mm)	I, ratio to shell diameter	II, ratio to shell diameter	III, ratio to shell diameter	I, ratio to thickness of corresponding whorl	II, ratio to thickness of corresponding whorl	III, ratio to thickness of corresponding whorl
Shell diameter	35	45	70	1.00	1.00	1.00	—	—	—
Umbilicus diameter	13	15	26	0.37	0.33	0.37	—	—	—
Last whorl.
Height above the suture	13	17	23	0.37	0.38	0.33	1.18	1.21	1.25
Same, preceding whorl	—	14	21	—	0.31	0.30	—	1.00	1.05
Thickness	11	14	20	0.31	0.31	0.29	1.00	1.00	1.00
Penultimate whorl.
Height above the suture	8	10	15	0.23	0.22	0.21	1.14	1.18	1.25
Thickness	7	8.5	12	0.20	0.19	0.17	1.00	1.00	1.00

A discoidal shell with a flat, broad umbilicus and high, slowly increasing whorls. The cross-section of the whorls is high, approaching elliptical; the siphonal side is somewhat flattened; the umbilical side is very gently sloping and almost merges with the lateral sides. The sculpture consists of weakly falciform ribs; the principal ribs, about 20 in number, begin near the umbilicus and extend almost evenly along the lateral sides; the intermediate ribs, numbering 1–2 in each interval, are intercalated, and on the siphonal side become completely similar to the principal ones. The ribs in general are narrow in comparison with the intervals separating them.

The suture line is of the type of Acanth. Aschiltaensis.

The young whorls are somewhat thicker, more rounded, and densely ribbed. The lateral tubercles on them are weakly developed.

Similarities and differences. From Acanth. Trautscholdi it differs in its sparser ribs and higher whorls, especially sharply at a diameter of about 40 mm. From Ammonites angulicostatus d’Orb. (Terr. Crét. I; p. 146; pl. 46; fig. 3–4) it differs sharply in its higher whorls, narrower siphonal side, and smaller number of intermediate ribs.

Locality. Khodzhal-Makha (3 specimens), probably from concretions of Aptian clay.

Distribution. Known only from the Caucasus and Mangyshlak. Probably from Aptian deposits.

68. Acanthohoplites stephanoides n. sp.

(plate IV, fig. 68; plate V, fig. 69).

Numerical data.

	In millimeters	Ratio to shell diameter	Ratio to thickness of corresponding whorl
Diameter of shell	51	1.00	—
Diameter of umbilicus	16	0.31	—
Last whorl.
Height above suture	21	0.41	1.05
Height above preceding whorl	16	0.31	0.80
Thickness	20	0.39	1.00
Penultimate whorl.
Height above suture	12	0.24	1.00
Thickness	12	0.24	1.00

An inwardly swollen shell with a deep, stepped umbilicus and fairly high whorls, showing rounded flanks and a somewhat flattened siphonal side up to 40 mm, and rather weakly convex flanks converging toward the flattened siphonal side later.

The sculpture consists of weakly falciform, sharp ribs. The main ribs, 20–25 in number, bear elongate umbilical tubercles near the umbilicus and are somewhat thickened on the siphonal side. The intermediate ribs, inserted 1–2 per interval, on the siphonal side become similar to the main ribs.

The suture line is preserved only roughly and recalls Acanth. Aschiltaensis.

The young whorls are thinner and rounder, and the main ribs on them bear strong lateral tubercles. Very large whorls (140 mm in diameter) have less sharp and thicker ribs and flat flanks and siphonal side.

Similarities and differences. The form described closely recalls some of the figures of Acanth. Trautscholdi (see above). The difference consists in the sharper ribbing, the early appearance of the flattened siphonal side, and the absence of a sharp change from dense ribbing to sparser and stronger ribbing with the growth of the shell.

Locality. Khodzhal’-Makha (2 specimens), probably from Aptian concretions.

69. Acanthohoplites Anthulai n. sp.

(plate V, fig. 70).

Numerical data.

	In millimeters	Ratio to shell diameter	Ratio to thickness of corresponding whorl
Diameter of shell	37	1.00	—
Diameter of umbilicus	11	0.30	—
Last whorl.
Height above the suture	16	0.43	1.23
Height above the preceding whorl	12	0.32	0.92
Thickness	13	0.35	1.00
Penultimate whorl.
Height above the suture	8	0.22	1.00
Thickness	8	0.22	1.00

A flat discoidal shell with a shallow umbilicus and high whorls, whose transverse section, owing to the flattening

on the siphonal side and, owing to the slight convexity of the flanks, approaches the form of a trapezium; the umbilical wall is steep.

The sculpture consists of not sharply expressed, weakly falciform ribs. The main ribs, numbering about 15, are swollen near the umbilical margin, weakened near the middle of the flanks, and again somewhat strengthened on the siphonal side. The intermediate ribs, 3–5 in number (most often 3), are inserted for the most part in the interval, have varying lengths, and sometimes are branches of one another or of the main ribs.

The suture line approaches that of Acanthohoplites Aschiltaensis.

The young whorls have a more rounded and thick cross-section, a smaller number of main ribs, and a larger number of intermediate ribs.

Similarities and differences. I am inclined to think that this very form was described by Anthula under the name Parahoplites angulicostatus d’Orb. (Kreidefoss. v. Kaukasus, p. 114) from the Aptian geodes of Akusha and Khodzhal-Makhi. From the true Ammonites angulicostatus d’Orb. (Terr. Crét. I; p. 146, pl. 46, fig. 3–4), the form described differs in having a narrower umbilicus, higher whorls, and a narrower siphonal side. The illustrations of Acanthohoplites Nolani Seunes sp. in Prof. Sinzow (Ammonitiden v. Mangyschlak; p. 503; Taf. VIII, Fig. 1–13), especially his var. pygmaea and subrectangulata (ibid., Fig. 4, 6, 7), are very reminiscent of Acanth. Anthulae. But the latter is distinguished by the absence of an interruption of the ribbing on the siphonal side and by a smaller number of main ribs.

Locality. Khodzhal-Makhi (2 specimens), probably from concretions in the Aptian clay.

70. Acanthohoplites Uhligi. Anthula sp. 1899.

(Pl. V, figs. 71–72).

1. Parahoplites Uhligi Anthula. Kreidefossilien v. Kaukasus, p. 114; Taf. X, Fig. 1.

2. Acanthohoplites Uhligi. Sinzow. Ammonitiden v. Mangyschlak; p. 498; Taf. VII, Fig. 9.

3. Parahoplites cf. Uhligi Sommermeier. Aptien und Albien v. Peru: p. 379.

My fairly numerous specimens differ in no essential respect from Anthula’s illustration. The number of main ribs on some of them is smaller than that given by Anthula and may fall to 27 (instead of 34).

Locality. Khodzhal-Makhi (3 specimens), probably from concretions in the Aptian clay; Khodzhal-Makhi from the same kind of concretion

No. 8 (1 specimen); Tsudakhar from similar concretions Nos. 1–11 (5 specimens); 67th verst of the Gunib road from a similar concretion (1 specimen and 2 fragments).

Distribution. Known from the Caucasus, Mangyshlak, and undoubtedly from Peru. In all probability an Aptian form.

71. Acanthohoplites compressus n. sp.

(Plate V, figs. 73–75).

Numerical data.

Specimens.	I	II	III	IV	I	II	III	IV	I	II	III	IV
Specimens.	In millimeters.	In millimeters.	In millimeters.	In millimeters.	Ratio to shell diameter.	Ratio to shell diameter.	Ratio to shell diameter.	Ratio to shell diameter.	Ratio to thickness of the corresponding whorl.	Ratio to thickness of the corresponding whorl.	Ratio to thickness of the corresponding whorl.	Ratio to thickness of the corresponding whorl.
Diameter of shell . . . . . .	37	44	58	75	1.00	1.00	1.00	1.00	—	—	—	—
Diameter of umbilicus . . . . . .	11	11	15	21	0.30	0.25	0.28	0.28	—	—	—	—
Last whorl.
Height above suture . . . . . .	15	19	22	32	0.41	0.43	0.40	0.43	1.25	1.36	1.15	1.23
Height of preceding whorl . . .	11	15	18	26	0.30	0.34	0.32	0.35	0.92	1.07	0.90	1.08
Thickness . . . . . .	12	14	20	24	0.32	0.32	0.35	0.32	1.00	1.00	1.00	1.00
Penultimate whorl.
Height above suture . . . . . .	6	9	10	16	0.16	0.20	0.18	0.21	0.80	1.00	0.91	1.23
Thickness . . . . . .	7.5	9	11	13	0.20	0.20	0.19	0.17	1.00	1.00	1.00	1.00

A flat, rather involute discoidal shell with a not deep umbilicus and high whorls, having a flat siphonal side, weakly convex flanks somewhat converging upward, and an inclined umbilical side.

The sculpture consists of several sickle-shaped, broad, rounded ribs. The main ribs, numbering about 17–20, are somewhat swollen near the umbilicus, weakened on the flanks, and again strengthened on the siphonal side. The intermediate ribs, 1–2 in each interval, are intercalated and on the siphonal side become similar to the main ribs. The suture line is of the type of Acanth. Aschiltaensis.

The young whorls are more rounded, have fewer main ribs and more threadlike intermediate ribs (up to 3–4 in an interval). Very large specimens, having 100–200 mm in diameter, bear up to 26 main ribs; the number of intermediate ribs in them reaches only 1 per interval.

Similarities and differences. From Acanth Ubligi it differs in less dense and sharp ribs, and in higher whorls in the young

age and by the more weakly developed, often almost entirely absent tubercles on the young whorls. It also resembles Acanth. subangulicostatus, n. sp., but differs in having broader and more rounded ribs.

Locality. Khodjal-Makha. (6 specimens), probably from concretions in Aptian clay; Khodjal-Makha in a similar concretion no. 11 (1 specimen).

72. Acanthohoplites evolutus. Sinzow. 1207.

1. Acanthohoplites evolutus. Sinzow. Ammonitiden v. Mangyschlak;
   S. 492; Taf. 10, Fig. 21—22.

A small specimen, already having, however, a living chamber, entirely similar to the figures of Prof. Sinzow. I am somewhat doubtful as to the assignment of this species to Acanthohoplites, from the typical representatives of which it differs sharply in general appearance. Perhaps this species should rather be referred to Douvilleiceras.

Locality. Khodjal-Makha (1 specimen), probably from Aptian concretions.

Distribution. Described by Prof. Sinzow from Mangyshlak.

73. Acanthohoplites. sp. 1.

Numerical data.

	In millim.	Ratio to shell diameter	Ratio to thickness of corresponding whorl
Diameter of the shell	21	1.00	—
Diameter of the umbilicus	7	0.33	—
Last whorl
Height above the suture	9	0.43	1.13
Height above the preceding whorl	8	0.38	1.00
Thickness	8	0.38	1.00
Penultimate whorl
Height above the suture	5	0.24	0.83
Thickness	6	0.29	1.00

The shell is small, with high, slightly involute whorls of rounded quadrangular cross-section. The sculpture consists of thin, weakly sickle-shaped ribs. The main ribs are slightly swollen at the umbilicus, numbering about 12; on the young part of the whorl they bear distinct lateral tubercles. Intermediate ribs on the living chamber are inserted, one or more rarely two to an interval. On the young part of the whorl their number is 2—4 per interval, and they differ from the main ribs only in the absence of tubercles. In the tubercles the main ribs

branch. The lobate line is not observed with sufficient clarity.

Similarities and differences. The fine-ribbed character distinguishes the described form from the one similar to it in transverse section of the whorls, Acanth. rectangularis n. sp. On the other hand, some resemblance is found with the form assigned by Prof. Sinzov (Ammonitiden v. Mangyschlak, p. 502, Pl. IV, Figs. 18–20) to Acanth. Bigoti Seunes sp. However, both the author of the species and Prof. Sinzov depict, in general, specimens too large for precise comparison with my small specimens. Fig. 18 of Prof. Sinzov’s cited plate depicts a specimen suitable in size, but, having the possibility of comparing only the lateral view of both specimens, I cannot state anything beyond a certain general resemblance.

Locality. Khodzhal-Makha (2 specimens), probably from concretions in the Aptian clay.

74. Acanthohoplites? sp. 2.

A fragment of an enormous ammonite with high whorls, a flat siphonal side, and very slightly convex flanks converging toward the siphonal side. The sculpture consists of dense, weakly sickle-shaped ribs, of which, so far as can be made out, half are principal ribs and half are inserted intermediate ribs.

Similarities and differences. Without showing clear identity with any species of Acanthohoplites known to me, this form may be the adult stage of many of them. The possibility of assigning it to Parahoplites Anthula is also not excluded.

Locality. Khodzhal-Makha (1 fragment).

Genus. Parahoplites Anthula 1899.

After the separation of Acanthohoplites and the separation, justified below, which I make from Parahoplites of the group Hoplites Deshayesii, the genus Anthula is reduced almost to a single Par. Melchioris, with closely adjoining, partly doubtful species. Other forms which I assign here to this genus are doubtful in the sense of their generic determination, since their resemblance to Par. Melchioris proves too general and superficial. A number of species referred here by Jacob also require revision, in view of the fact that this latter author took only slight account of the fact that the type of the genus is Par. Melchioris, and therefore, in generic determinations, relied on the relations of his species with forms which may not even belong to Parahoplites.

75. Parahoplites Melchioris Anthula 1899.

(Pl. V, figs. 76–78; pl. VI, fig. 79).

1. Parahoplites Melchioris. Anthula. Kreidefossilien v. Kaukasus; S. 112; Taf. VIII, Fig. 4–5.
2. Parahoplites Melchioris. Sinzow. Ammonitiden v. Mangyschlak; S. 458; Taf. II, Fig. 1–4.

Numerical data.

Specimens	I, in mm	II, in mm	III, in mm	IV, in mm	V, in mm	VI, in mm	I, ratio to shell diameter	II, ratio to shell diameter	III, ratio to shell diameter	IV, ratio to shell diameter	V, ratio to shell diameter	VI, ratio to shell diameter	I, ratio to height of corresponding whorl	II, ratio to height of corresponding whorl	III, ratio to height of corresponding whorl	IV, ratio to height of corresponding whorl	V, ratio to height of corresponding whorl	VI, ratio to height of corresponding whorl
Shell diameter	16	28	53	55	62	76	1.00	1.00	1.00	1.00	1.00	1.00	—	—	—	—	—	—
Umbilicus	5	8	13	14	17	20	0.31	0.29	0.25	0.25	0.27	0.26	—	—	—	—	—	—
Last whorl
Height above the suture	6	12	23	24	26	33	0.38	0.43	0.43	0.44	0.42	0.43	0.75	1.00	1.05	1.14	1.13	1.10
Height of preceding whorl	5	9	20	20	22	25	0.31	0.32	0.38	0.36	0.35	0.33	0.63	0.75	0.91	0.95	0.96	0.83
Thickness	8	12	22	21	23	30	0.50	0.43	0.42	0.38	0.37	0.39	1.00	1.00	1.00	1.00	1.00	1.00
Penultimate whorl
Height above the suture	4	6	12	13	14	18	0.25	0.21	0.23	0.24	0.23	0.24	0.80	0.86	1.00	1.00	1.08	1.20
Thickness	5	7	12	13	13	15	0.31	0.25	0.23	0.24	0.21	0.20	1.00	1.00	1.00	1.00	1.00	1.00

This very common Dagestan form has been described and figured in detail by Anthula and Prof. Sinzow. The somewhat unsatisfactory figure of the lobate line in the former author shows that in reality it is nevertheless somewhat more complicated. Characteristic of the lobate line is usually considered to be the rather broad body and the irregular, asymmetrical end of the first lateral lobe. This latter generally has the outer branch larger than the inner one. This distinction is not very constant, and cases occur of almost complete symmetry of both branches. It is not possible to separate specimens with such an almost symmetrical first lateral lobe, since differences in this respect are sometimes observed on one and the same specimen. A second characteristic feature of the lobate line described is the great breadth of the saddles and the weak development and irregularity of the second lateral and auxiliary lobes. In my material there are very small specimens of Par. Melchioris. These specimens are distinguished by almost round whorls and are almost smooth. The typical sculpture of the species appears, however, already at 6–10 mm diameter, in the form of curved and low, but distinctly falciform ribs breaking up into

the main and intermediate ribs, never interrupted on the siphonal side. Tubercles are also not observed on these young specimens.

Similarities and differences. Anthula includes in the synonymy of this species Acanthoceras n. f. Neumayr und Uhlig (Hilsammonitiden; S. 180; Taf. XV, Fig.) and Hoplites Deshayesi of K. I. Bogdanovich (On the geology of Central Asia; p. 126; figs. 11—12). In my opinion, the illustration by Neumayr and Uhlig is insufficient for exact comparison, and the reference to K. Bogdanovich is apparently erroneous: Anthula probably had in mind not the form cited by him, but another form, described by K. Bogdanovich on p. 131 of the same work and illustrated there on pl. III, fig. 5 and in fig. 13 in the text. This latter form is very similar to Par. Melchioris, but has higher whorls. The thicker and more densely ribbed form separated by Prof. Sinzov (Ammonitiden v. Mangyschlak; S. 459; Taf. II, Fig. 5—11) under the name Par. multicostatus cannot be separated in my material, although variations in the sense of the density of the ribs and the form of the cross-section were observed by me in Par. Melchioris.

Locality. Khodzhal-Makha (29 specimens), probably from concretions in Aptian clay; Khodzhal-Makha from the same concretions No. 11 (1 specimen); Saltynskaya station in gray sandy marl No. 3 (15 fragments); Mekegi (1 fragment) in gray sandy marl; Kuna (6 fragments) in gray sandy marl; Kaka-Makha (6 specimens) in gray sandy marl.

Distribution. Described from the Caucasus, Mangyshlak, and also reported from Persia. Everywhere, in all probability, in Aptian deposits.

76. Parahoplites Campichei Sinzow 1907 (non. Pictet et Rénevier. 1854).

1. Parahoplites Campischi Sinzow. Ammonitiden v. Mangyschlak; S. 460; Taf. I, Fig. 4—7.

A specimen about 94 mm in diameter, corresponding rather exactly to the illustrations of Prof. Sinzov. The lobate line appears somewhat more complex, but this circumstance is apparently connected with the conditions of preservation. Typically it is sufficiently similar to the examples illustrated by Prof. Sinzov and shows the same asymmetrical first lateral lobe and broad saddles.

Similarities and differences. In view of the fact that Ammonites Campichei Pictet et Rénevier (Perte du Rhône; p. 25; pl. II, fig. 2) shows,

weaker ribs, well-developed umbilical tubercles, and a somewhat narrower siphonal side, I should, in my opinion, more cautiously regard the Caucasian form as a distinct species. In general appearance it more resembles some species of Acanthohoplites than Parahoplites Melchioris. Nevertheless, the asymmetry of the first lateral lobe and the broad saddles make its closest relationship to Parahoplites more probable.

Locality. Khodzhaly-Macha (1 specimen), probably from concretions in the Aptian clay.

Distribution. Described by Prof. Sinzow from Mangyshlak.

77. Parahoplites Sjögreni Anthula 1899.

1. Parahoplites Sjögreni. Anthula. Kreidefossilien v. Kaukasus; S. 116; Taf. XI, Fig. 2—3.

2. Sonneratia Sjögreni (pars.) Sinzow. Ammonitiden v. Mangyschlak; S. 466; non. Taf. II, Fig. 14—15.

Numerical data.

	In millim.	Rel. to shell diam.	Rel. to thickness of corresponding whorl
Diameter of shell	276	1.00	—
Diameter of umbilicus	62	0.22	—
Last whorl.
Height above suture	128	0.46	1.10
Height above preceding whorl	96	0.35	0.83
Thickness	116	0.42	1.00
Penultimate whorl.
Height above suture	66	0.24	1.09
Thickness	60	0.22	1.00

I have given numerical data relating to a specimen that deviates somewhat from the type by the greater narrowness of the umbilicus and the greater thickness of the whorls. Other specimens correspond more closely to Anthula’s type. It is quite probable that this species should be subdivided, but for such a subdivision it is necessary to break up a considerable number of large specimens, for which my material is insufficient. It is very possible that various species of Parahoplites in the adult state will prove similar to Par. Sjögreni.

Similarities and differences. Prof. Sinzow proposes to assign Par. Sjögreni to the genus Sjorneratia Bayle, basing his proposal on the similarity of the lobate lines. If one has in view the typical species of the genus Sonneratia: Sonneratia Dutempleana d’Orbigny sp., then this similarity proves to be rather superficial. The best-known illustrations to me of the lobate line of Sonneratia Dutempleana are given by Sarasin

(Hoplites, Sonneratia etc.; p. 781; fig. 12) and Jacob (Ammonites du Crétacée moyen; p. 57, fig. 39). Comparing them with the lobate line of Par. Sjögreni (figured, for example, by Prof. Sinzow, l. c.; p. 469; Fig. IV), one sees that the 1st lateral lobe in Par. Sjögreni is considerably more asymmetrical, the saddles are broader, and the size of the lobate elements diminishes toward the suture without anything like the gradualness seen in Sonneratia Dutempleana. The lobate line visible in Taf. II, Fig. 14–15 in Prof. Sinzow, and referred by him to Sonneratia Sjögreni, bears very little resemblance to the lobate line depicted by him in the text, and has narrow and long saddles, which indeed recall certain representatives of Sonneratia in Jacob. It should, of course, not be overlooked that the relationship of Par. Sjögreni with Par. Melchioris is likewise not very well proven. But a certain general similarity of the lobate lines (the asymmetry of the 1st lateral lobe and the broad saddles), and an analogy of sculpture with Par. Campischei Sinzow, make Anthula’s assignment of the species to the genus Parahoplites more consistent with our present average understanding of the group of forms belonging here. In my view, one cannot deny certain analogies in the sculpture and lobate line between representatives of Sonneratia and Parahoplites Melchioris and other species of this genus. It is possible that the connection between Sonneratia and Parahoplites will prove closer than has hitherto been thought; nevertheless, in the present state of affairs, it is more prudent to leave Ammonites Sjögreni in the genus Parahoplites than to transfer it to the still little-defined and very disputed genus Sonneratia.

Locality. Khodzhat-Makha (3 specimens), probably from concretions in Aptian clay; Lavashi, in gray sandy marl No. 1 (1 specimen); Saltinskaya station, in bluish-gray marl No. 2 (1 fragment); Shakh-Dag, in gray sandy marl (1 fragment).

Distribution. A species very widespread in the Caucasus in Aptian deposits; the inclusion here of the form described by Prof. Sinzow from Mangyshlak appears doubtful for the reasons set forth above.

78. Parahoplites aff. Milletianus D’Orbigny sp. 1840.

1. Ammonites Milletianus. D’Orbigny. Terr. Crét. I; p. 263; pl. 77.

2. Ammonites Milletianus D’Orbigny. Prodrome II; p. 123; et 19 Albien No. 27.

?1851. Ammonites Milletianus. Abich. Versteinerungen v. Daghestan; SS. 21 et 23.

1. Ammonites Milletianus. Pictet et Rénevier. Perte du Rhône p. 22.

1. Ammonites Milletianus. Pictet et Campiche. Sainte Croix I; p. 260: pl. XXXVII, fig. 2—5.

2. Acanthoceras Milleti. Kilian. Montagne de Lure II; p. 54.

3. Sonneratia Miletiana. Parona e Bonarelli. Fossili Albiani; p. 87; tav. XIV, fig. 17.

4. Acanthoceras cf. Milleti Karakash. Cretaceous deposits of the Caucasus; p. 27; pl. IV, fig. 7.

1905 Parahoplites Milletianus. Jiacob. Clausages; p. 411, pl. XIII, fig. 3.

Fragments differing from the type in having flatter lateral sides and more weakly developed tubercles. In part they prove to be identical with the illustrations in N. I. Karakash.

Locality. Lavashi, in gray sandy marl; No. 4 (1 specimen); Lavashi (1 specimen) in gray sandy marl; Kaka-Makha (1 specimen).

Distribution. The species is usually regarded as Lower Albian and Upper Aptian. It is known from France, Switzerland, Italy, and the Caucasus.

79. Parahoplites n. f. ind.

A fragment of a whorl, covered with rather fine, sickle-shaped, irregularly branching ribs, some of which on the more juvenile part of the fragment bear strong lateral tubercles. On the siphonal side the ribs are arched forward in an arc. The cross-section of the whorls is not high, rounded.

Similarities and differences. It has some general resemblance to the young whorls of Par. Melchioris, but the ribbing is somewhat sharper, the whorls are lower, and in Par. Melchioris there are never any lateral tubercles.

Locality. Kaka-Makha (1 specimen).

80. Parahoplites sp. 1.

A fragment of a rather high whorl with a rounded quadrangular cross-section. The sculpture consists of several strong sickle-shaped ribs, with the main ribs regularly alternating with inserted intermediate ones.

Similarities and differences. The character of the ribs recalls Parahoplites aff. Milletianus d’Orb. sp., and the possibility is not excluded that in the present case this is an adult whorl of the same form.

Locality. Lavashi, in gray sandy marl No. 1 (1 specimen).

§1. Parahoplites. sp. 2.

A crushed fragment of a rather large ammonite, somewhat resembling Par. Sjögreni, but showing a somewhat weaker ribbing than that observed at the same size in Par. Sjögreni.

Locality. Kupa (1 specimen), in gray sandy marl.

Genus. Hoplites Neumayr. 1875.

Hoplites was established by Neumayr (Kreide Ammoniten; S. S. 925–927) originally in a purely genetic sense. Under the name Hoplites were united the descendants of Perisphinctes from the groups polyplosus and involutus, which had lost the umbilical lobe and constrictions and had acquired a sickle-shaped character of the ribs and a smooth band on the siphonal side. After the separation from among the representatives of Hoplites of a series of species into the genera Acanthoceras and Stoliczkaia, established in the same year by Neumayr, the genus Hoplites contained 4 Jurassic and 45 Cretaceous species. Since the basis of the author’s understanding of the genus Hoplites was a purely genetic point of view, this genus, already at the very beginning, included forms very different morphologically, and within a short time its splitting became inevitable.

The subsequent history of the genus is reduced to the separation from it of Sonneratia Bayle; Pulchellia Uhlig and Aulacostephanus Sutner et Pomipecki, and to the addition to it of the group Ammonites Leopoldinus d’Orb. In addition, many new species were described.

As a result, in 1884 Zittel (Handbuch der Palaeontologie II; S. S. 475—477), again attaching to the genus Hoplites Sonneratia Baule and Stoliczkaia Noumayr, counted in the genus about 80 Cretaceous and 2–3 Tithonian species. All these species Zittel divided into 6 groups: 1. group Amm. radiatus Brng; 2. group Amm. cryptoceras d’Orb. 3. group Amm. interruptus Brng.; 4 group Amm. Deshayesi d’Orb.; 5 group Amm. dispar d’Orb = Stoliczkaia Neum; 6 group Amm. Dutempleanus d’Orb.; = Sonneratia Bayle.

In 1897 Sarasin (Hoplites, Sonneratia, Desmoceras et Puzosia; p. p. 762—780) undertook a new revision of the genus Hoplites. Sonneratia and Stoliczkaia are again considered here as independent genera. The remaining species are distributed into 4 groups, only partly corresponding to Zittel’s groups. 1 group Hopl. neocomiensis d’Orb sp., beginning with the Aptian, is divided into three subgroups: a Hoplites Deshayesi Leym. sp. b. Hopl. gargasensis d’Orb. sp. c. Hopl. Dufrenoyi d’Orb. sp.; this group embraces part of Zittel’s group Hoplites Deshayesi. 2 group Hoplites amblygonium Neumayr. et Uhlig embra-

comprises the group Hopl. cryptoceras and part of the group Hopl. Deshayesi Zittel. The 3rd group, Hoplites Leopoldinus, almost coincides with Zittel’s group Amm. radiatus. The 4th group, Hoplites interruptus, embraces the greater part of Zittel’s group of the same name.

In 1899 Anthula (Kreidefossilien v. Kaukasus; pp. 109–120) established the genus Parahoplites for forms that were predominantly new and transitional between Hoplites and Douvilleiceras. Of the former species, this included some representatives of the groups Hopl. neocomiensis and amblygonius, and some forms previously referred to Acanthoceras.

After that, several more genera and subgenera were published, of which I shall not speak separately, but shall pass directly to the two existing attempts to synthesize all these partial results.

One of these attempts belongs to Jacob (Ammonites du Crétacé moyen, pp. 43–61) and is dated 1907. Here the generic concept of Hoplites is again understood broadly; that is, Sonneratia Bayle and Parahoplites Anthula are included in it as subgenera.

Leaving aside the Neocomian forms and restricting himself to the treatment of Aptian and Albian forms, the author considers all these latter forms as offshoots of the subgenus Parahoplites Anthula. This genus or subgenus Parahoplites is understood by Jacob not as Anthula understood it. Jacob excludes from Parahoplites all forms leading to Par. Aschiltaensis, refers them to Douvilleiceras, and joins to Parahoplites the old group Hopl. Deshayesi. The resulting double series of forms, distinguished in part by straight ribs, develops widely in the Albian deposits, giving here a number of new subgenera. The group with straight ribs retains in Jacob the old subgeneric name Parahoplites and is represented in the Albian deposits by the group Parahoplites Milletianus. This group partly represents the genus Acanthohoplites Sinzow, already mentioned above. The group with sickle-shaped ribs gives rise to the main mass of Hoplitids of the Gault, breaking up here into 3 subgenera: 1. Leymeriella Jacob = the group Amm. tardefurcatus Léym. and regularis Brng. 2. Hoplites s. str. = the group Amm. dentatus Sow. 3. Sonneratia Bayle.

The second attempt to synthesize the results relating to the genus Hoplites Neumayr belongs to Uhlig. Uhlig’s work, originally published in 1905, appeared in its final form only in 1910 (Spiti Shales; pp. 152–183). Here Uhlig distinguishes among ...

for hoplitids a whole series of genera and subgenera, whereas, in contrast to Jacob, he deals almost exclusively with Jurassic and Neocomian forms, only glancing over the Aptian and Albian ones. As separate genera Uhlig considers: 1. Aulacostephanus Sutner et Pomęczki—the group Amm. Eudoxus d’Orb. 2. Berriasella Uhlig, embracing the more primitive forms of the former group Hopl. neocomiensis. 3. Blanfordia Uhlig, embracing certain predominantly new Indian forms. 4. Acanthodiscus Uhlig, embracing strongly tuberculate species formerly assigned to the groups Hopl. Leopoldinus and amblygonnius. The remaining Neocomian forms are left under the generic name Hoplites and are divided into the following subgenera: 1. Thurmannia Uhlig. 2. Leopoldia Baumberger. 3. Sarasinella Uhlig. 4. Neocomites Uhlig. The subgenus Hoplites s. str. is to unite the principal mass of Albian forms connected with Hopl. interruptus. Barremian, Aptian, and part of the Albian forms were left by Uhlig in an indeterminate position; he noted only, without precisely defining their scope, the genus or subgenus Parahoplites Anthula and the groups Hopl. Deshayesi Leym. sp., furcatus Spw. sp., regularis Brng. sp. Kilian, in 1910 (Lethaea geognostica; S.S. 180–187; 216–223; 268–269; 279, 280 etc.), gave a somewhat scattered summary of data on the hoplitids of the Neocomian and partly of the Aptian. With respect to most Neocomian hoplitids Kilian closely follows Uhlig, differing from him here and there only in assigning individual forms to one place or another. Parahoplites Anthula Kilian accepts almost in Jacob’s sense, separating from it only the group Hopl. angulicostatus d’Orb. sp. and referring this group to Neocomites Uhlig; Hoplites furcatus Phill. sp. (= Dufrenoyi d’Orb. sp.) Kilian refers to Neocomites. I do not consider it possible to adhere wholly to any one of the classifications cited. Leaving aside the Neocomian hoplitids absent from my material, I shall speak chiefly of the Aptian forms, with respect to which my material is fairly abundant. First of all, I cannot agree with the conception of the genus Parahoplites Anthula established by Jacob and Kilian. If one proceeds from their conception, then the central form of the genus is Hopl. Deshayesi Leym. sp., but as the type of Anthula’s genus one should take not Hopl. Deshayesi but Parahoplites Melchioris Anthula. This latter form, however, shows no resemblance to Hopl. Deshayesi either in the lobe line or in individual development. The thick young whorls of Par. Melchioris, which never show an interruption of ribbing on the siphonal side, have decidedly nothing in common with the young whorls of Hopl. Deshayesi. Lo-

the suture line in Par. Melchioris is considerably simpler and shows a characteristically weak development of the second lateral lobe, which in Hopl. Deshayesi has the normal size for hoplites. On the other hand, Hopl. Deshayesi at a young age shows a great similarity to Hopl. furcatus Phill. sp. This similarity extends both to the sculpture and to the suture line, and sometimes reaches the point where distinction becomes difficult. For this reason I consider it more natural to unite Hopl. Deshayesi and furcatus into one group. This group is apparently most closely connected with Neocomites Uhlig, in which I adhere to a certain extent to Sarasin’s old views, but it presents the peculiarity that the interruption of the ribbing on the siphonal side disappears with age, and the siphonal side itself changes from flat to rounded. On the basis of all this I consider it more rational to exclude Hopl. Deshayesi from the genus Parahoplites and to form from it, together with Hopl. furcatus, Weissi, and related forms, a new subgeneric group.

Subgenus Hoplites s. str. Jacob. 1907.

1. Hoplites. cf. dentatus Sowerby sp. 1823.

2. Ammonites dentatus. Sowerby. Mineral conchology IV; p. 3; pl. 303.

3. Hoplites dentatus. Parona et Bonarelli. Fossili Albiani; p. 91; tav. XII, fig. 2—5; tav. XIV, fig. 3.

See also the synonymy there.

Specimens deformed by pressure, whose sculpture is indistinguishable from the sculpture of Sowerby’s species. In the absence of the possibility of examining the cross-section, and with some deformation of the sculpture itself, the determination remains doubtful.

Locality. Tsudakhar in light-colored marl J (3 specimens); Gergebil in a similar marl No. 1 (1 specimen).

Distribution. Sowerby’s species is the usual guiding form of the Albian stage. Its geographic distribution is difficult to establish because of confusion with closely related species. One may indicate England, France, Switzerland, central Russia, the Caucasus, and the Transcaspian region as localities where the presence of Hopl. dentatus has been established with comparative certainty.

1. Hoplites. sp.

(Plate VI, fig. 80)

A fragment of a hoplite deformed by pressure, with numerous fine ribs, running irregularly from the umbilical tubercles. Much more finely ribbed than Hoplites dentatus,

Locality. Kaka-Makha (1 specimen) in light-gray marl.

Subgenus Deshayesites nov. subg.

To this new subgenus I assign hoplitids allied to Hopl. Deshayesi, Weissi, and furcatus. Morphologically it may be characterized as follows. The shell is flat, discoidal, with high whorls, having in youth a flattened, later rounded siphonal side. The sculpture consists of more or less falciform ribs; about half of the ribs are primary and begin near the umbilical margin; the remaining ribs are intermediate, begin near the middle of the flanks, and toward the siphonal side rapidly become equal in strength to the primary ribs. On young whorls all the ribs end near the boundary of the flattened siphonal side, sometimes extending somewhat onto the latter, and in this way a smooth band is formed along the middle of the siphonal side. Later the siphonal side becomes rounded. The ribs begin to pass across it without interruption, at first weakening somewhat in its middle, then without such weakening. Finally, on the siphonal side the ribs attain their greatest strength. The lobate line is comparatively simple. The siphonal lobe is shorter than the first lateral, sometimes considerably shorter. The external saddle is broad, bifid, with a higher, usually antisiphonal branch. The first lateral lobe is rather broad and usually noticeably asymmetrical. The first lateral saddle is high and narrow. The second lateral lobe is about half the size of the first. There usually follows a bifid second lateral saddle and a small auxiliary lobe and saddle. As a rule there is no sutural lobe.

Similarities and differences. Among Neocomian hoplitids my new subgenus approaches most closely the subgenus Neocomites Uhlg. The sculpture of the young whorls of Hoplites furcatus Sow. sp. is very close to the sculpture of the young whorls of Hoplites (Neocomites) neocomiensis d’Orb. sp.; one may say that it is almost identical with it. The expansions of the ribs toward the siphonal side, which distinguish Hopl. furcatus, appear only when the shell has a diameter of 10–15 mm. Young Hopl. Deshayesi, in their turn, are very similar to somewhat more adult Hoplites furcatus. The difference between Deshayesites and Neocomites comes down to the fact that in the former subgenus, with age, rounding of the siphonal side takes place and the smooth band along the middle of the latter disappears. In Hopl. furcatus the smooth band disappears comparatively late, and the siphonal side, up to the largest sizes known to me, remains—

is rather flat, and in this respect it comes closer to the true Neocomites.

The resemblance to Parahoplites Anthula is noticeable in Hoplites Deshayesi, but it always remains superficial. The typical species of the genus Parahoplites—Par. Melchioris Anth.—has a sharply different character in the young whorls, which always show a low, rounded transverse section and a complete absence of interruption of the ribs on the siphonal side. The resemblance of the suture lines is likewise not great and amounts only to a certain asymmetry of the first lateral lobe and to a broad saddle in both groups. On the other hand, the suture line of Deshayesites shows a shorter siphonal lobe, a narrow first lateral saddle, and a normal second lateral lobe, which in Par. Melchioris is comparatively very small.

As a result, Deshayesites differs from Neocomites by a somewhat simpler suture line without a sutural lobe and by the disappearance of the smooth band on the siphonal side at mature age. From Parahoplites, Deshayesites differs in the hoplitid sculpture of the young whorls and in the stronger development of the second lateral lobe, with an altogether somewhat more complex suture line.

Kilian (Lethaea geognostica S.S. 222—223) derives Hopl. (in his usage Parahoplites) Deshayesi from Thurmannia Uhlig through Hopl. Cruasensis Torc. In the absence of any reasoning in Kilian, it is difficult to dispute this opinion. However, the suture line of Thurmannia Thurmanni Pict. et Camp. sp. (see Kilian, l. c. Taf. 3.) shows greater differences from the suture line of Hopl. Deshayesi (see Sarasin: Hoplites, Sonneratia etc.; p. 768), having a narrow, relatively external saddle, long branches of an almost symmetrical first lateral lobe, and an enormous, comparatively, second lateral lobe. Therefore the rapprochement of Hopl. Deshayesi with Thurmannia seems to me, in general, little substantiated. In view of the striking analogies of the suture lines of Hopl. Deshayesi and furcatus, the latter of which is already assigned by Kilian to Neocomites, it is also hardly reasonable to ascribe a different origin to these two species.

84. Hoplites (Deshayesites) Deshayesi Leymerie sp. 1842.
(Plate VI, figs. 81—83; Plate VII, figs. 100—101)

1. Ammonites Deshayesi. D’Orbigny. Ter. Crét. I; p. 288; pl. 85, fig. 1—4.

2. Ammonites Deshayesi. Leymerie. Aube; p. 15 et. 32; pl. 17 fig. 17.

3. Ammonites Deshayesi. Forbes. Lower greensand fossils; p. 353. pl. V. fig. 2.

1. Ammonites Deshayesi. Quenstedt. Cephalopoden; S. 344.

2. Ammonites fissicostatus (pars). D’Orbigny. Prodrome II; p. 113—ét. 18: Aptien, No. 24.

3. Ammonites Deshayesi. Abich. Fossilien v. Daghestan; S. 21.

4. Ammonites Deshayesi. Pictet et Campiche. Sainte Croix I; p. 341.

5. Ammonites Deshayesi. Lahusen. On the fossils of the Simbirsk clay; p. 37; pl. VI, fig. 5.

6. Hoplites Deshayesi. Neumayr und Uhlig. Hilsammonitiden; S. 177; Taf. XLVI, Fig. 2—3 (Taf. XLV, Fig. 1?)

7. Hoplites Deshayesi (pars.). Kilian Montagne de Lure II; p. 10.

8. Hoplites Deshayesi. Pavlow et Lamplugh. Les argiles de Speeton; p.p. 203 et 468.

9. Hoplites Deshayesi. Karakash. Cretaceous deposits of the Caucasus; p. 25; pl. II, fig. 3.

10. Hoplites Deshayesi. Sarasin. Hoplites, Sonneratia, Desmoceras et Puzosia; p.p. 767—768; fig. 4.

11. Hoplites Deshayesi. Anthula. Kreidefossilien v. Kaukasus; S. 108.

12. Hoplites Deshayesi. v. Koenen. Neocammonitiden; S. 204; Taf. XLV, Fig. 10.

13. Hoplites aff. Deshayesi. v. Koenen Neocammonitiden; S. 206.

14. Parahoplites Deshayesi. Jacob. Ammonites du Crétacé moyen.; p. 46; fig. 28.

15. Hoplites Deshayesi. Krenkel. Delagoa Bai.; S. 164.

Despite the extensive literature, of which only a part is cited in the above list, Hopl. Deshayesi still remains, in essence, a collective form. V. Koenen (l.c.), among the group of forms belonging here from the German Gault, distinguishes rather clearly three: 1. the true Hopl. Deshayesi; 2. Hopl cf. Deshayesi, figured by Neumayr and Uhlig (l.c.) on pl. XLV; 3. Hopl. aff. Deshayesi, figured by the same authors on pl. XLVI. Kilian (Lethaea geognostica; S.S. 279 ff.) distinguishes: 1. Hopl. Deshayesi Leym. sp. 2. Hopl. Rhodanicus Kil. sp. 3. Hopl. consobrinus d’Orb. sp. Of these forms, Hopl. Rhodanicus is not entirely clear. According to the author it should represent Hopl. Deshayesi of Neumayr and Uhlig, but whether it is the one figured by the named authors on pl. XIVI remains unclear.

In my rather large material I was able to distinguish three forms, differing from one another chiefly in their more or less dense ribbing. The more coarsely ribbed form corresponds well to Hopl. consobrinus; the finely ribbed one is described by me below as a new species. The form with a medium density of ribs is accepted

I regard it as the present Hopl. Deshayesi. To justify this with complete rigor is rather difficult. Usually, as the starting point in determining what should be considered Hopl. Deshayesi, the figures of d’Orbigny and Leymerie are taken. Meanwhile, these figures refer to somewhat different forms. The figure of d’Orbigny shows a form with more widely spaced ribs, a flatter siphonal side, and an interruption of the ribbing on this side even at a shell diameter of 30 mm. Leymerie depicts a more densely ribbed form, which at the same diameter has a ribbed siphonal side. The specimens accepted by me as the present Hopl. Deshayesi correspond very precisely to Leymerie’s drawing at a diameter of 30 mm. The interruption of the ribbing and the flat siphonal side are preserved in our specimens only up to 15–20 mm diameter. Such young specimens, when they occur in association with more adult whorls, are rather difficult to distinguish from young Hoplites furcatus. The thickening of the ribs toward the siphonal side, observed in the latter to a considerably more pronounced degree than in Hopl. Deshayesi, is here the most convenient distinguishing character. Specimens that would correspond perfectly to d’Orbigny’s figure are absent from my material, but deviations in the corresponding direction are observed in quite many specimens. In some of them the flat siphonal side and the interruption of the ribbing on it persist up to 30 mm in diameter, but the lateral sides are less convex and the whorls somewhat higher than in the form figured by d’Orbigny. It is very likely that this form should be regarded as a distinct species, but I do not have sufficient data for establishing it as such.

Locality. Khodzhal-Makhi (10 specimens) in gray sandy marl; Khodzhal-Makhi in concretions of Aptian clay No. 11 (12 specimens); Lavashi from gray sandy marl No. 1 (45 fragments); Tsudakhar from similar marl (23 specimens); Kupa from similar marl (2 fragments); Shakh-Dag in similar marl (1 specimen); moreover, very large comparative fragments and specimens, the identification of which is somewhat doubtful, occur from Lavashi in gray sandy marl (3 fragments), Tsudakhar in gray sandy marl No. 4 v. (2 fragments), and Saltinskaya Station in gray sandy marl No. 3 (2 specimens).

Distribution. Hopl. Deshayesi is an Aptian species; for the most part it is recorded from Lower Aptian deposits, more rarely from Upper Aptian deposits. Its geographical distribution is broad. Pri-

at a certain risk of confusion with closely related species, one may indicate England, France, northern Germany, Spain, northern Africa, Russia, the Caucasus, the Transcaspian region, India, Madagascar, and Australia.

85. Hoplites (Deshayesites) consobrinus D’Orbigny sp. 1840.

(Pl. VI, fig. 84).

1. Ammonites consobrinus. D’Orbigny. Terr. Crét.; p. 147; pl. 47.

2. Ammonites consobrinus. Quenstedt. Cephalopoden; S. 340.

3. Ammonites fissicostatus (pars). D’Orbigny. Prodrome II; p. 113; ét. 18 Aptien, No. 24.

4. Ammonites consobrinus. Pictet et Campiche. Sainte Croix I; p. 341.

5. Hoplites Deshayesi (pars). Kilian. Montagne de Lure II; p. 10.

6. Hoplites consobrinus. Krenkel. Delagoa Bai; S. 164.

Numerical data.

Specimens	I, in millimeters	II, in millimeters	III, in millimeters	I, ratio to shell diameter	II, ratio to shell diameter	III, ratio to shell diameter	I, ratio to thickness of corresponding whorl	II, ratio to thickness of corresponding whorl	III, ratio to thickness of corresponding whorl
Diameter of shell	23	28	33	1.00	1.00	1.00	—	—	—
Diameter of umbilicus	8	9	11	0.35	0.32	0.33	—	—	—
Last whorl.
Height above suture	10	11	14	0.43	0.39	0.42	1.67	1.55	1.56
Height above preceding whorl	9	9	12	0.39	0.32	0.36	1.50	1.29	1.36
Thickness	6	7	9	0.26	0.25	0.27	1.00	1.00	1.00
Penultimate whorl.
Height above suture	5	6	7	0.22	0.21	0.21	1.25	1.20	1.40
Thickness	4	5	5	0.17	0.18	0.15	1.00	1.00	1.00

To this species I assign small specimens differing from Hopl. Deshayesi by rarer and stronger ribs and usually by higher whorls. With respect to the latter character, considerable fluctuations are observed, and specimens are encountered that differ from Hopl. Deshayesi only by somewhat coarser ribbing. The siphonal side, in general, preserves a flat character longer than in Hopl. Deshayesi. The interruption of the ribbing is for the most part observed up to a diameter of 25 mm, but not infrequently it disappears earlier. The form described is especially difficult to distinguish from individuals of Hopl. Deshayesi approaching those figured by d’Orbigny (Terr. Crét. I; pl. 85, fig. 1—4). Drawing the boundary between the species here is purely conventional, and I draw it on the basis of

chiefly by the greater or lesser rarity and strength of the ribs. With a diameter of about 40 mm, over 3 cm of length measured on the siphonal side, Hopl. Deshayesi has 9 ribs, whereas Hopl. consobrinus has 7 ribs; with a diameter of about 23 mm, over the same and similarly measured length, Hopl. consobrinus has 14 ribs, while the most sparsely ribbed variety of Hopl. Deshayesi has 18 ribs.

Locality. Khodzhal-Makha (11 specimens), probably from gray sandy marl. Tsudakhar (6 specimens), probably from the same kind of marl; Lavashi from gray sandy marl No. 1 (9 specimens).

Distribution. The species is usually regarded as chiefly Lower Aptian. Its geographic distribution is probably as wide as that of Hopl. Deshayesi, but, because of confusion with the latter, only France can be indicated with certainty.

86. Hoplites (Deshayesites) cf. Weissi Neumayr und Uhlig, 1881.

1. Hoplites Weissi. Neumayr und Uhlig. Hilsammonitiden; S. 179; Taf. XLVI, Fig. I; Taf. XLVII, Fig. 1.

2. Hoplites Weissi. Kilian. Montagne de Lure. II; p. 10.

3. Hoplites cf. Weissi. Sinzow. Ammoniten des Aptien; S. 14, Fig. 10 et 10a; Taf. A. Fig. 12—13.

4. Hoplites. Weissi. V. Koenen. Neocomammonitiden; S. 207; Taf. XLIII, Fig. 3; Taf. XLV, Fig. 1.

5. Hoplites Weissi. Karakash. Lower Cretaceous deposits of Crimea; p. 92; pl. VI, fig. 2.

Fragments of small specimens, differing from Hopl. Deshayesi by weaker and denser ribbing, might be referred to Hopl. Weissi.

Locality. Lavashi in gray sandy marl No. 1 (5 fragments).

Distribution. Hopl. Weissi is regarded as a Lower Aptian form and is cited from Germany and France. N. I. Karakash describes it from the Barremian stage in Crimea.

87. Hoplites (Deshayesites) n. f. aff. Weissi Neumayr und Uhlig 1881.

(Pl. VI, fig. 85).

A fragment of an ammonite more than 200 mm in diameter. The shell is flat, discoidal, with high elliptical whorls and a rather steep umbilical wall. The ribbing of the adult whorls is very close to that observed in Hopl. Deshayesi, but the ribs are somewhat

more often. At a diameter of about 80–90 mm the number of intermediate ribs is increased, and in the middle of the lateral sides the ribs are weakened, on the nucleus to the point of being barely visible. The suture line is typically similar to the suture line of Hopl. Deshayesi.

Similarities and differences. From Hopl. Deshayesi the form under consideration differs in its more frequent, and on the young whorls also less sharply defined, ribs. From Hopl. Weissi, to which the form under consideration is very close, it differs in its less numerous and stronger ribs on the adult whorls.

Locality. Tsudakhar, from concretions in Aptian clay no. 1 (1 specimen).

88. Hoplites (Deshayesites) Lavaschensis n. sp.

(Plate VI, figs. 86–87.)

Numerical data.

Specimens	I	II	I	II	I	II
	In millimeters	In millimeters	Ratio to shell diameter	Ratio to shell diameter	Ratio to the thickness of the corresponding whorl	Ratio to the thickness of the corresponding whorl
Shell diameter	24	39	1.00	1.00	—	—
Diameter of umbilicus	6	10	0.25	0.25	—	—
Height above the suture, last whorl	11	18	0.46	0.46	1.57	1.64
Height above the preceding whorl, last whorl	—	13	—	0.33	—	1.18
Thickness, last whorl	7	11	0.29	0.28	1.00	1.00
Height above the suture, preceding whorl	6	9	0.25	0.23	1.20	1.50
Thickness, preceding whorl	5	6	0.21	0.15	1.00	1.00

A flat, discoidal shell with rather involute, high whorls, with an elongate-elliptical cross-section; the umbilical wall is gently sloping. The sculpture consists of thin, falciform ribs. The main ribs, numbering 25–30 on the adult whorls and up to 40 on the young whorls, begin at the umbilicus and partly branch in the middle of the lateral sides; the intermediate ribs, 1–2 in each interspace, are predominantly intercalated, but sometimes appear as branches of the main ribs. On the siphonal side all the ribs are equal and arcuately bent forward; up to 15–20 mm the siphonal side is flat, and on it an interruption of the ribbing is observed. Later it becomes rounded, and the ribs cross it without interruption, even becoming stronger on it. The suture line is typically similar to that in Hopl. Deshayesi.

Similarities and differences. It rather closely resembles Hoplites Deshayesi Leym. sp., but differs in its much more frequent and thinner ribs. At a diameter of about 40 mm, along 3 cm of length on the siphonal side, Hopl. Lavaschensis has 13 ribs instead of the 9 observed in Hopl. Deshayesi. The young whorls resemble Hopl. (Neocomites) Neocomiensis d’Orb. sp. Terr. Crét. I; p. 202; pl. 59, fig. 8—10), but are nevertheless distinguished by the lesser swelling of the principal ribs of the umbilical margin and by the less sharply defined smooth band on the siphonal side.

Locality. Lavashi in gray sandy marl (5 specimens); Tsudakhar in similar marl (5 specimens).

89. Hoplites (Deshayesites) aff. Lavaschensis mihi.

Small specimens close to Hopl. Lavaschensis, but distinguished by still thinner and more frequent ribs. At a diameter of 25 mm the number of ribs over 3 cm along the siphonal side reaches 28—30. Not knowing the adult whorls, I do not venture to state definitely whether this form should be regarded as a new species or as a variety of Hopl. Lavaschensis.

Locality. Lavashi in gray marl No. 1 (3 obl.).

90. Hoplites (Deshayesites) furcatus. Sowerby sp. 1836.

(Pl. VI, figs. 88—91)

1. Ammonites Dufrenoyi D’Orbigny. Terr. Crét. I; p. 200; pl. 33, fig. 4—6.

2. Ammonites furcatus. Forbes. Lower greensand fossils; p. 353.

3. Ammonites Dufrenoyi. Quenstedt. Cephalopoden; S. 158; Taf. X, Fig. 10.

4. Ammonites furcatus D’Orbigny. Prodrome II; p. 114; ét. 18 !7. Neocomien A Inférieur. No. 49.

5. Ammonites Dufrenoyi. D’Orbigny. Prodrome II; p. 114; ét. 18 Aptien, No. 32.

6. Ammonites Dufrenoyi. Pictet et Renevier. Perte du Rhône; p. 22.

7. Ammonites Dufrenoyi. Pictet et Renevier. Perte du Rhône; p. 171.

8. Ammonites furcatus. Pictet et Campiche. Sainte Croix I; p.p. 217 et 329.

9. Hoplites furcatus. Kilian. Montagne de Lure II; p.p. 10 et 32.

10. Hoplites Dufrenoyi. Sarasin. Hoplites, Sonneratia etc; p. 769; fig. 6.

11. Hoplites furcatus. V. Koenen. Neocomammonitiden; S. 202.

1. Hoplites (Neocomites) furcatus. Kilian. Lethaea geognostica; Taf. 8, Fig. 3.
2. Hoplites furcatus et Dufrenoyi. Krenkel. Delagoa Bai; p. 164.

Numerical data.

Specimens	I, in millimeters	II, in millimeters	I, ratio to shell diameter	II, ratio to shell diameter	I, ratio to thickness of corresponding whorl	II, ratio to thickness of corresponding whorl
Shell diameter	30	50	1.00	1.00	—	—
“ umbilicus	8	14	0.27	0.28	—	—
Last whorl: height above suture	13	22	0.43	0.44	1.44	1.57
Last whorl: height above preceding whorl	—	20	—	0.40	—	1.43
Last whorl: thickness	9	14	0.30	0.28	1.00	1.00
Penultimate whorl: height above suture	8	—	0.27	—	1.33	—
Penultimate whorl: thickness	6	—	0.20	—	1.00	—

A discoidal shell with a not wide umbilicus and high whorls, having a narrow and flat siphonal side, a slightly convex lateral side, and a steep umbilical wall. The sculpture consists of falciform ribs that broaden toward the siphonal side. About half of these ribs are principal and begin at the umbilicus. The others are intermediate and begin near the middle of the lateral sides, and then quickly become completely like the principal ribs. All the ribs end near the boundary of the siphonal side with the lateral sides, thus forming in the middle of the siphonal side an interruption in the ribbing. This interruption, however, exists fully only up to a diameter of 20 mm. At a larger diameter the siphonal side is crossed by broad and flat continuations of the ribs, and at a diameter of about 40–50 mm these continuations become equal in strength to the ribs themselves and form a noticeable forward bend on the remaining rather flat siphonal side. The young whorls are distinguished, besides a greater or lesser smoothness of the siphonal side, also by the fact that instead of intercalation of ribs, branching predominates on them.

The suture line, by the short siphonal lobe, the broad external saddle, and the asymmetry (more or less sharp) of the first lateral lobe, is typically similar to the suture line of Hopl. Deshayesi.

Similarities and differences. With the general similarity of the lobate lines and sculpture, the young whorls are sometimes rather difficult to distinguish from the young whorls of Hopl. Deshayesi. The distinction is reduced to the more clearly expressed expansion of the ribs toward the siphonal side in Hopl. furcatus. Already at a diameter of 20–25 mm both forms differ sharply from one another. A certain convergence of characters again occurs at a shell diameter of 40–50 mm, but here Hopl. furcatus differs sharply from Hopl. Deshayesi by its flat siphonal side and thicker ribs.

Locality. Lavashi, in gray sandy marl No. 1 (about 30 specimens and fragments); Tsudakhar, in a similar marl (fragment).

Distribution. The species is regarded as Upper Aptian. It is known from England, northern Germany, France, Spain, Switzerland, from the Caucasus, and from Texas.

91. Hoplites (Deshayesites) subfurcatus n. sp.

(Table VII, figs. 92–93).

	In millim.	Ratio to shell diam.	Ratio to thickness of corresponding whorl
Diameter of shell	24	1.00	—
Diameter of umbilicus	6	0.25	—

Last whorl.

	In millim.	Ratio to shell diam.	Ratio to thickness of corresponding whorl
Height above the suture	11	0.46	1.57
Height of preceding whorl	—	—	—
Thickness	7	0.29	1.00

A discoidal shell with a rather narrow umbilicus and high whorls, having a narrow flat siphonal side, slightly convex flanks, and a steep umbilical wall. The sculpture consists of numerous falciform ribs, expanding toward the siphonal side. About half of these ribs are principal ribs and begin at the umbilicus. The remaining ribs are intermediate; they begin near the middle of the flanks and then quickly become like the principal ribs. All the ribs end near the boundary of the siphonal side with the flanks, thus forming, in the middle of the siphonal side, an interruption in the ribbing. This interruption persists up to a diameter of about 30 mm. At a larger diameter the siphonal side is crossed at first by weak, then by increasingly stronger continuations of the ribs, which ultimately form a noticeable forward bend on the siphonal side, which remains flat throughout.

In the young whorls the intercalation of ribs is replaced by branching. The lobate line is typically similar to that of Hopl. Deshayesi.

Similarities and differences. From Hopl. furcatus it differs by its thinner and more frequent ribs. Owing to the fragmentary nature of the material it is difficult to characterize this difference by precise numerical data, and it is most convenient to show it in the figures. With ribs finer than in Hopl. furcatus, Hopl. subfurcatus approaches more closely to Hopl. Deshayesi, from which in the adult state it differs, in the end, only by the flat siphonal side.

Locality. Lavashi, in gray sandy marl no. 1 (9 specimens).

92. Hoplites (Deshayesites) sp. 1.

Fragments of moulds of a discoidal shell with high whorls, a rather narrow umbilicus, and greatly weakened ribbing. The cross-section of the whorls is oval. The ribs are broad, flat, falciform; the intermediate ribs arise by intercalation between the main ribs, one in each interval. The young whorls show more distinct ribbing, but the ribs on them are thicker and rarer than in Hopl. Deshayesi. Since the very youngest whorls, showing the presence or absence of a smooth band on the siphonal side, are unknown, even the generic determination is doubtful.

Locality. Lavashi, in gray sandy marl no. 1 (4 specimens); Lavashi, in similar marl no. 5 (1 specimen).

93. Hoplites (Deshayesites) sp. 2.

Fragments of a form very close to the preceding one, but showing lower whorls, a wider umbilicus, and clearer ribs, which are nevertheless thicker and rarer and less sharp than in Hopl. Deshayesi.

94. Hoplites (Deshayesites) sp. 3.

A fragment of a high whorl with a rather flat siphonal side and with thick and low ribs widening toward the siphonal side. The intermediate ribs arise generally by intercalation, in one particular case by branching. In my opinion it might be a fragment of a very large specimen of Hopl. furcatus.

Locality. Lavashi, in gray sandy marl no. 5 (1 specimen).

Family Desmoceratidae,
genus Desmoceras Zittel 1884.

In my understanding of this genus I follow Kilian (Lethaea geognostica; pp. 255–263), who gave a general survey of the forms belonging here, a survey which appears to correspond to a high degree with the present state of our knowledge of Desmoceras.

95. Desmoceras Saltense n. sp.

(Plate VII, figs. 94–95).

Numerical data

Specimens	I, in millimeters	II, in millimeters	I, ratio to shell diameter	II, ratio to shell diameter	I, ratio to thickness of corresponding whorl	II, ratio to thickness of corresponding whorl
Diameter of shell	33	46	1.00	1.00	—	—
Diameter of umbilicus	7	10	0.21	0.22	—	—
Last whorl.
Height above suture	15	22	0.45	0.48	1.07	1.10
Height above preceding whorl	10	14	0.30	0.30	0.71	0.70
Thickness	14	20	0.42	0.43	1.00	1.00
Penultimate whorl.
Height above suture	9	14	0.27	0.30	1.13	1.17
Thickness	8	12	0.24	0.26	1.00	1.00

A discoidal shell with a narrow, step-like umbilicus, having almost vertical walls, and with rather high involute whorls. The sculpture consists of sickle-shaped furrows, the bends of which are very sharp, almost angular. Besides these, only sickle-shaped growth marks are visible, leaving traces also on the nucleus. The sickle-shaped furrows appear only beginning with a diameter of 30–35 mm.; earlier only the growth marks are visible.

The suture line has the first lateral lobe somewhat longer than the siphonal one and somewhat asymmetrical; the asymmetry is expressed in the fact that the antisiphonal branch of the first lateral lobe is smaller than the siphonal branch and departs somewhat lower than the latter.

Similarities and differences. I am inclined to bring the form described here close to Desmoceras Melchioris Tietze sp. (Ammoniten von Swinitza; p. 135; Pl. IX, figs. 9–10), from which, however, my form …

differs by the later appearance of the furrows, their more sharply curved form, and the narrower umbilicus in large specimens. The enlargement of the umbilicus that is seen when comparing figs. 10 and 9 of Tietze’s cited plate is not observed in my form. From Desmoceras Falloti Kilian (Lethaea geognostica; p. 258. Karakash, Cretaceous deposits of the Crimea; p. 75; pl. VII, figs. 4 and 8; pl. VIII, fig. 6 under the name Desm. Melchioris) my form differs in greater involution, as well as in more sharply curved furrows appearing later.

Locality. Salty station (1 specimen); Khodzhal-Makha (3 specimens)—all probably come from concretions in Aptian clay.

Genus. Puzosia. Bayle. 1878.

I also understand the scope of this genus in the sense of Kilian. Latidorsella Jacob, given the present state of our knowledge, is more conveniently regarded as a subgenus of Puzosia, especially in view of the uncertain position of the group Puz. Emerici d’Orb. sp., which in some characters approaches Latidorsella and is regarded by Kilian as Puzosia, by Jacob as Latidorsella.

Subgenus. Puzosia s. str.

96. Puzosia planulata Sowerby sp. 1829.

1. Ammonites planulatus. Sowerby. Mineral Conchology VI; p. 136; pl. 570, fig. 5.

2. Desmoceras (Puzosia) Mayori. Karakash. Cretaceous deposits of the Caucasus; p. 21; pl. VI, figs. 8—10 and 12 (pars?).

3. Puzosia planulata Kossmat. Südindische Kreideformation II; p. 112; pl. XVI, figs. 4—5; pl. XVII, fig. 1.

For data on the synonymy and history of this species, see Kossmat (l. c.) and Jacob (Ammonites du Crétacé moyen; pp. 38—41).

Completely flattened specimens in black shaly marl, in all essentials identical with the cited figures of N. I. Karakash. Specific determination is, under the present conditions of preservation, very difficult. N. I. Karakash described this form as Puzosia Mayori, without distinguishing Amm. Mayorianus d’Orb. and Ammonites planulatus Sow. However, these species had already been clearly distinguished by Bayle, and their difference was discussed in detail by Kossmat and Jacob. The distinguishing characters are reduced almost exclusively to proportions of size and to the structure of the suture line. The latter cannot be studied on the Cauc—

specimens, and in order to ascertain the proportional dimensions one has to resort to an indirect method, since on directly compressed specimens the necessary data cannot be obtained. Having measured in the figure of Jacob’s (l. c. pl. XVI, fig. 1) the length of half the outline of Puz. Mayoriana, viewed from the front, and then half the length of the outline, viewed from the same side, of the transverse section of the last whorl, I determined the ratio of the second length to the first and obtained 0.40. The same data for Par. planulata, from the figure of Kosmat (l. c. Taf. XVIII, Fig.), gave the figure 0.48. Selecting from my material a specimen which appears flattened with preservation of symmetry, I obtained for the same magnitudes a ratio of 0.47, i.e. one approaching Par. planulata.

Locality. Gergebil, in black shaly marl No. 2 (8 specimens).

Distribution. It is regarded as a Cenomanian form, appearing already in the very uppermost part of the Albian stage. Its geographical distribution is wide, but, owing to confusion with closely related species, cannot be outlined precisely. The species is known almost everywhere where deposits of suitable age are observed, from England to India and Sakhalin, and is also cited from Brazil.

97. Puzosia Matheroni. D’Orbigny sp. 1840.

1. Ammonites Matheroni. D’Orbigny sp. Terr. Crét. I; p. 148; pl. 48, fig. 1—2.

2. Ammonites cesticulatus. Leymerie. Aube; p.p. 15 et 32; pl. 17, fig. 19.

3. Ammonites Matheroni. D’Orbigny. Prodrome II; p. 113; ét. 18 Aptien, No. 25.

4. Ammonites cesticulatus. Pictet et Campiche; Sainte Croix I; p. 361.

5. Desmoceras Matheroni. Kilian. Mantagne de Lure II; p.p. 9 et 32.

6. Puzosia Matheroni. Kilian. Lethaea geognostica; Taf. 8, Fig. 1.

To this species I assign small specimens, almost exclusively internal molds, covered with clearly visible though weak ribs and almost straight constrictions at the apertures, representing folds bordered in front and behind by furrows. The number of intermediate ribs is smaller than in the figures of d’Orbigny and Kilian, but this difference could depend on the smaller size of my specimens. Leymerie’s small Amm. cesticulatus appears not to differ from my specimens.

Similarities and differences. Following d’Orbigny and Pictet, I unite Amm. Matheroni and cesticulatus. Kilian (Mont. de Lure II; p. 32) holds the opposite opinion. As I have already said, the young whorls of my specimens are indistinguishable from Amm. cesticulatus, while the adults evidently approach Amm. Matheroni, nevertheless showing a smaller size and a smaller number of intermediate ribs. Under these conditions, and in the absence in Kilian of a statement of the reasons for his opinion, I fear confusing age differences with specific ones and therefore adhere to the older, broader understanding of this species.

Locality. Khodzhal’-Makha in gray sandy marl No. 11 (2 specimens); Lavashi in similar marl No. 1 (2 specimens); Tsudakhar in similar marl No. 4 c. (1 specimen).

Distribution. The species is usually regarded as Lower Aptian and is known from France and Switzerland.

98. Puzosia Liptoviensis Zeusсhner sp. 1856.

1. Desmoceras Liptoviense. V. Koenen, Neocomammonitiden. S. 62; Taf. XLIII, Fig. 1.

See the remaining literature there.

A form very close to Par. Matheroni, but distinguished by more sickle-shaped traces of the aperture. The latter have a less regular character than in Par. Matheroni, since the grooves bordering the folds of these traces are less distinct and sometimes are clearly visible only on one side of the fold. Kilian (Lethaea geognostica, SS. 262—263) assigns this species to the genus Puzosia, and I follow him in the present case, relying on the close similarity of Amm. Liptoviensis to Puzosia Matheroni. Sarasin and Schöndelmeyer (Châtel Saint Denis, pp. 40—42) assign the form under consideration to the genus Holcochiscus Uhlig, for which I do not see sufficient grounds.

Locality. Lavashi in gray sandy marl No. 1 (5 specimens); Tsudakhar in similar marl (1 specimen).

Distribution. The species is usually regarded as Barremian, but in northern Germany it is known also from the Lower Aptian. Its geographical distribution is as yet little studied: one may indicate southeastern France, northern Germany, and the Carpathians.

Group Puzosia Emerici d’Orbigny sp.

99. Puzosia Belus D’Orbigny sp. 1840.

1. Ammonites Belus. D’Orbigny, Terr. Crét. I; p. 166; pl. 52; fig. 4—6.

1. Ammonites Belus. D’Orbigny. Prodrome II; p. 114; ét 18 Aptien, No. 30.
2. Ammonites Belus. Pictet et Campiche. Sainte Croix I; r. 361.
3. Desmoceras Belus. Kilian. Montagne de Lure II; p.p. 10 et. 32.
4. Puzosia Belus. Sarasin. Hoplites, Sonneratia, Desmoceras Puzosia; p. 795.

Several specimens correspond very closely to d’Orbigny’s illustration. Traces of the intermediate ribs are also somewhat visible on the nucleus, and the umbilical wall is somewhat more steeply inclined toward the lateral sides than is shown by d’Orbigny. I do not venture, on the basis of these insignificant differences, to establish a new species.

Locality. Khodzhal-Makhi (8 specimens) in a gray sandy marl; 1 doubtful fragment from Lavashi in gray sandy marl No. 1.

Distribution. The species is usually regarded as Upper Aptian and is known from France and Switzerland.

100. Puzosia falcistriata Anthula sp. 1899.

1899, Desmoceras falcistriatum. Anthula. Kreidefossilien v. Kaukasus; S. 103; Taf VIII, Fig. 2.
1905. Desmoceras falcistriatum. Jacob. Clausages; p. 402.

Numerical data.

	In millim.	Ratio to shell diam.	Ratio to thickness of corresponding whorl
Diameter of shell	112	1.00	—
Diameter of umbilicus	31	0.28	—

Last whorl.

	In millim.	Ratio to shell diam.	Ratio to thickness of corresponding whorl
Height above the suture	48	0.43	1.14
Height above preceding whorl	38	0.34	0.89
Thickness	42	0.38	1.00

Penultimate whorl.

	In millim.	Ratio to shell diam.	Ratio to thickness of corresponding whorl
Height above the suture	24	0.21	1.04
Thickness	23	0.21	1.00

The specimen, consisting entirely of air chambers, has sculpture on the nucleus consisting of constrictions and faintly visible traces of intermediate ribs. Where part of the shell thickness is preserved, instead of constrictions, thick sickle-shaped folds are visible at the site of the constrictions, and the intermediate ribs are seen more clearly. With complete

when the shell is preserved, the intermediate ribs are again less distinct, and between the constrictions the growth marks come to the fore. The lobate line recedes somewhat near the umbilical margin, but a clearly expressed sutural lobe is not formed.

Similarities and differences. Sommermeier (Aptien und Albien v. Peru; p. 373) doubts that Puzosia Emerici d’Orb. sp. and Puz. falcistriata represent different species. According to his indication, the specimen from Peru which he had for study shows mixed characters of both forms. My specimen clearly shows all the distinguishing characters of Puz. falcistriata, i.e., a steeply falling umbilical wall, a broad umbilicus, ribs that are more curved on the lateral sides and straighter on the siphonal side than is observed in Puzosia Emerici. The somewhat greater height of the whorls of my specimen in comparison with Anthula’s species must be attributed to its larger size and is thus an age-related, not a species-distinguishing, character. In view of all this, I prefer to retain Puz. falcistriata as an independent species.

Locality. Khodjal-Makha (1 large and 3 small specimens), probably from concretions in Aptian clay; a doubtful fragment from the Salminskaya station from a layer of sandy marl No. 3.

Distribution. The species is accepted by Anthula as Aptian. Known from the Caucasus and from the Clausage horizon in France.

Subgenus Latidorsella Jacob. 1907.

101. Puzosia (Latidorsella) aff. latidorsata Michelin sp. 1838.

(Plate VII, fig. 96).

1. Ammonites latidorsatus. Michelin. Argile, dépendante du gavet; p. 101; pl. XII, fig. 9

2. Ammonites latidorsatus. D’Orbigny. Terr. Crét I; p. 27; pl. 80.

3. Ammonites latidorsatus. Leymerie. Aube; p. 32.

4. Ammonites latidorsatus. Quenstedt. Cephalopoden; S. 222.

5. Ammonites latidorsatus. D’Orbigny. Prodrome. II, p. 123; ét. 19. Albien No. 30; p. 146; ét 20 Cénomanien No. 14.

6. Ammonites latidorsatus. Pictet et Campiche. Sainte Croix I; p. 187.

7. Ammonites diphylloides. Stoliczka. Cretaceous of Southern India; p. 119; pl. LIX, fig. 8—11.

8. Ammonites inanis. Stoliczka. Ibidem; p. 121; pl. LIX, fig. 13—14.

9. Ammonites latidorsatus. Stoliczka. Ibidem; p. 148; pl. LXXIV, fig. 1—4.

1. Puzosia latidorsata. Sarasin. Hoplites, Sonneratia, Desmoceras, Puzosia, p. 795; fig. 19.

2. Desmoceras latidorsatum. Parona e Bonarelli. Fossili Albiani; p. 79; tav. X, fig. 8.

3. Desmoceras latidorsatum. Kossmat. Südindische Kreideform. S. 107; Taf. XIX, fig. 2—5.

4. Desmoceras inane. Kossmat. Ibidem; S. 107; Taf. XIX, Fig. 6—7.

5. Desmoceras n. sp. aff. inane. Kossmat. Ibidem; S. 108.

6. Desmoceras diphylloides. Kossmat. Ibidem; S. 108; Taf. XIX. Fig. 8—9.

7. Desmoceras phyllimorphum. Kossmat. Ibidem. S. 110.

8. Latidorsella latidorsata. Jacob. Ammonites du Crét moyen; p. 35; pl. XIV, fig. 10—14; pl. XV, fig. 1—2.

I accept for this species the broad interpretation proposed by Jacob. With such an interpretation, my single specimen, with a narrow and deep sharply delimited umbilicus, thick whorls, and a rounded siphonal side, can hardly be separated from Puz. latidorsata. The character of the umbilicus, the suture line, and the transverse section of the whorls are identical with the intermediate varieties of Puz. latidorsata, approaching Puz. inanis of Kossmat. A noticeable difference of my specimen consists in the fact that, in addition to the usual constrictions, there is also observed on it a weak intermediate undulating folding, which is somewhat visible also on the nucleus. Therefore I consider it more cautious to regard the Caucasian form as aff.

Locality. Khodzhal-Makha (1 specimen), probably from the concretions in the Aptian clay.

Distribution. The species is regarded as Albian and Cenomanian. Its geographical distribution is broad and includes France, Switzerland, North America, the Baconian Forest, and India. It has very rarely been cited from Aptian deposits.

102. Puzosia (Latidorsella) Akuschaensis. Anthula sp. 1899.

1. Desmoceras Akuschaense. Anthula. Kreidefossilien v. Kaukasus; S. 104; Taf. VIII, Fig. 3.

2. Desmoceras Akuschaense. Jacob. Clausages; p. 402; pl. XII. Fig. 1.

Several predominantly young specimens, having whorls somewhat higher than the type of Anthula. The transition of the fold, characteristic of the species, near the margin of the constriction, from the anterior side to the posterior side is observed on most of the constrictions in all specimens; but certain individual constrictions have a somewhat different character: the fold remains the whole time on one side of the constr—

...the constriction, showing only a sharp bend in the corresponding direction, leading to a narrowing of the constriction. On the basis of higher whorls it would be possible to regard the form described as a distinct species, but given the present state of our information on Puz. Akuschaensis, I consider its separation risky and in any case premature.

Locality. Lavashi (2 specimens) in gray sandy marl; 1 doubtful fragment in gray sandy marl No. 2 from the Salta station.

Distribution. Known from the Caucasus, from France, and Morocco. Jacob indicates it for the Clausayes horizon.

Family Harpoceratidae.

Genus Oppelia Waagen. 1869.

Subgenus Adolphia. Stolley. 1906.

103. Oppelia (Adolphia) Nisus. D’Orbigny sp. 1840.

1. Ammonites Nisus. D’Orbigny. Terr. Crét. I; p. 184; pl. 55, fig. 7—9.

2. Ammonites Nisus. D’Orbigny. Prodrome II; p. 112; ét. 18 Aptien, No. 10.

3. Ammonites Nisus. Pictet et Campiche. Sainte Croix I; p. 302.

4. Desmoceras Nisus. Kilian. Montagne de Lure II; p. 32.

5. Oppelia Nisus. Sarasin. Oppelia et Sonneratia; p. 152.

6. Oppelia (Adolphia) Nisus. Kilian. Lethaea geognostica; Taf. 8, Fig. 4.

7. Oppelia Nisus. Krenkel. Delagoa Bai; S. 142; Taf. XVII, Fig. 1.

Fragments which, in transverse section, the suture line, and the character of the surface, fully correspond to this species.

Locality. Lavashi in gray sandy marl No. 1 (3 fragments); Salta station in similar marl No. 3 (1 fragment).

Distribution. The species is regarded predominantly as Upper Aptian. Its geographical distribution is broad and includes Germany, England, France, northern Italy, Spain, northern Africa, and the Caucasus.

Family Lytoceratidae.

Genus Baculites Lamarck 1801.

104. Baculites? sp.

(Pl. VII, fig. 97).

A flattened fragment of the apertural part of a shell, covered with rather thin, forward-arched folds, numbering ...

about 8 per 1 cm on the only visible siphonal side. Specific determination is impossible, and even the generic determination is doubtful.

Similarities and differences. The ribs are much more frequent than in Baculites Gaudini Pictet et Campiche (Sainte Croix II; p. 112; pl. LV, fig. 5–11) and thinner than in Baculites Sanctae Crucis Pictet et Campiche (ibidem; p. 109; pl. LV, fig. 1–4). My specimen shows greater similarity to Baculites sp. of N. I. Karakash (Cretaceous deposits of the Caucasus; p. 32; pl. VI, fig. 15), but this latter baculite is compressed in another direction, and therefore an exact comparison is impossible.

Locality. Gergebil, in black shaly marl No. 2.

Genus Turrilites. Lamarck. 1801.

105. Turrilites aff. elegans D’Orbigny. 1840.

(Pl. VII, fig. 98).

1. Turrilites elegans. D’Orbigny. Terr. Crét. I; 577; pl. 140, fig. 6—7.

2. Turrilites Bergeri var. elegans. Quenstedt. Cephalopoden; S. 301.

3. Turrilites elegans. D’Orbigny. Prodrome II; p. 126; ét. 19: Albien No. 90.

4. Turrilites elegans. Pictet et Campiche. Sainte Croix II; p. 125; pl. LVI, fig. 9—10; pl. LVII, fig. 8—10.

? 1897. Turrilites sp. Karakash. Cretaceous deposits of the Caucasus; p. 33.

A fragment about 20 mm long, measured along the siphonal side; the diameter of the transverse section at the anterior end is about 11 mm, at the posterior about 7.5 mm. Fairly strong oblique ribs bear 4 rows of tubercles, the distance between the centers of which in the siphonal row is about 4 mm. The siphon is situated between the two middle rows of tubercles. If the rows of tubercles are numbered from above (from the apex of the shell) downward (toward its base), then the distance between rows 1 and 2 will be about 2.5 mm, between the 2nd and 3rd about 3 mm, and between the 3rd and 4th almost 3.5 mm. The lobate line is poorly visible owing to the poor condition of the surface of the fragment, although the latter consists entirely of air chambers.

Similarities and differences. The similarity to Turr. elegans is expressed in the presence of four rows of tubercles and the median position of the siphon. The difference is reduced to a coarser sculpture and to a greater closeness of the 2nd and 3rd rows of tubercles in comparison with the 3rd and 4th in my form. As to the relations to Turrilites sp. of N. I. Karakash (l. c.), I consider it impossible, in the absence of a figure, to express myself categorically.

Locality. Lavashi, in gray sandy marl No. 4.

Distribution. The species is regarded as Upper Albian and Lower Cenomanian, and is distributed in England, France, and Switzerland. Turrilites sp. in N. I. Karakash comes from the Aptian deposits of the Caucasus.

Genus Pictetia Uhlig. 1883.

106. Pictetia sp. ind.

A fragment of a mold, 52 mm long (measured on the siphonal side); at the anterior end the height of the transverse section is 27 mm, the thickness 24 mm; at the posterior end the height is 23 mm, the thickness 20 mm. The sculpture consists of weak ribs; on the flanks these ribs are almost imperceptible on the mold, while on the siphonal side they are clearer; their number is about 4 per 1 cm on the siphonal side. On the antisiphonal side the ribs are not visible.

The suture line is of the Lytoceratidae type, with paired, strongly branched and very finely incised lobes and saddles.

Similarities and differences. It is fairly similar to Pictetia Astieriana d’Orb. sp. (Terr. Crét. I; p. 468; pl. 115 bis, fig. 3—5), but differs in a somewhat stronger sculpture and in higher whorls. It should probably be regarded as a new species, but less fragmentary material is needed for its establishment.

Locality. Lavashi, in gray sandy marl No. 5 (1 fragment); a doubtful fragment in the same kind of marl from Kupa.

Genus Tetragonites Kossmat 1895.

107. Tetragonites Duvalianus. D’Orbigny sp. 1840.

1. Ammonites Duvalianus. D’Orbigny. Terr. Crét. I; p. 158; pl. 50, fig. 4—6.

2. Ammonites Duvalianus. D’Orbigny. Prodrome II; p. 113; ét. 18. Aptien, No. 27.

3. Ammonites Duwalianus. Abich. Daghestan-Fossilien; S. 24.

4. Ammonites Duvalianus. Pictet et Campiche. Sainte Croix I; p. 362.

5. Lytoceras Duvali. Kilian. Montagne de Lure II; p. 31.

6. Lytoceras (Tetragonites) Duvalianum. Kossmat. Südindische Kreidef.; I. S. 132.

7. Lytoceras (Tetragonites) Duvalianum. Anthula. Kreidefossilien v. Kaukasus; S. 99; Taf. VII, Fig. 3.

8. Tetragonites Duvalianus. Jacob. Clausages; p. 401.

9. Tetragonites Duvalianus. Jacob et Tobler. Engelberger Aa; p. 9.

10. Lytoceras (Tetragonites) Duvalianum. Kilian. Lethaea geognostica; Taf. 8, Fig. 5.

To this species I assign 2 specimens and 1 fragment, relying chiefly on Anthula’s illustrations. Both of my specimens are smaller than the one figured by Anthula and have weaker and rarer constrictions. Since the same weakening of the constrictions toward the inner whorls is also visible in Anthula’s figure, the grounds for uniting my specimens with the form figured by him under the name Lyt. Duvalianum are sufficient. The figure in d’Orbigny differs appreciably from what is shown by Anthula in the form of the cross-section. A fragment of a larger specimen in my material in this respect resembles d’Orbigny’s illustration. Under these circumstances I do not venture to separate my specimens and the form described by Anthula from d’Orbigny’s species.

Locality. Khodzhal-Makhi (2 specimens), probably from gray sandy marl; Saltinskaya station, in gray sandy marl No. 3 (1 fragment).

Distribution. The species is regarded as Aptian, distributed in southern France, Switzerland, and the Caucasus.

108. Tetragonites heterosulcatus Anthula sp. 1899.

1. Lytoceras (Tetragonites) heterosulcatus. Anthula. Kreidefossilien v. Kaukasus; S. 99; Taf. VII, Fig. 4—5.

To this species I assign several fragments similar to Anthula’s figures in the cross-section of the whorls and in the suture line. One larger fragment bears strong and frequent constrictions, recalling what is observed in adult Tetr. Duvalianus. Its cross-section, however, has the form of the cross-section of Tetr. heterosulcatus, and therefore I am more inclined to take this fragment as a fragment of an adult specimen of the latter species.

Locality. Khodzhal-Makhi, from concretions in Aptian clay No. 8 (fragments of 2 specimens).

Distribution. Aptian deposits of the Caucasus.

Genus Jaubertella. Jacob. 1907.

109. Jaubertella cf. Jaubertiana. D’Orbigny sp. 1850.

1. Ammonites Jaubertianus. D’Orbigny. Prodrome II; p. 113; ét. 18, Aptien, No. 20.

2. Lytoceras Jauberti. Kilian. Montagne de Lure II; p. 31.

3. Jaubertella Jaubertiana. Jacob. Ammonites du Crétacé Moyen; p. 17; pl. II, fig. 13—16.

To this species I assign, with some doubt, a fragment similar to Jacob’s figures in the suture line and possessing—

…with a transverse section not exceeding the range of variation in the form of this section shown by Jacob for Jaubertella Jaubertiana.

Similarities and differences. I am not entirely certain that the form under consideration is not a variety of Jaubertella latericarinata Anthula sp. (Kreidefossilien v. Kaukasus; p. 101; Pl. VII; Fig. 2) from the Aptian deposits of the Akusha valley, since the distinctive characters of this latter species cannot be established on the fragment.

Locality. Salta station, in gray sandy marl No. 3 (1 specimen).

Distribution. Aptian and Albian deposits of southern France.

Family Phylloceratidae

Genus Phylloceras Suess. 1865.

110. Phylloceras Rouyanum. D’Orbigny sp. 1840.

1. Ammonites Rouyanus. D’Orbigny. Terr. Crét. I; p. 362; pl. 110, fig. 3—5.

2. Ammonites Rouyanus (pars). D’Orbigny. Prodrome II; p. 98; ét Néocomien; B. Supérieur No. 579.

3. Ammonites Rouyanus (pars). Pictet et Campiche. Sainte Croix I; p. 347.

4. Ammonites Rouyanus. Tietze; Ammoniten v. Swinitza; p. 133; Pl. IX, Fig. 7—8.

5. Phylloceras Rouyanum. Kilian. Montarne de Lure II; p. 31.

6. Phylloceras Rougi. Karakasch. Cretaceous deposits of the Caucasus; p. 10; pl. IV, fig. 6.

7. Phylloceras Rouyanum. Anthula. Kreidefossilien v. Kaukasus; p. 54.

8. Phylloceras Rouyanum. Kilian. Lethaea geognostica; p. 254.

A small specimen, corresponding very perfectly to the original figure and description in d’Orbigny.

In the understanding of this species there exist numerous disagreements, and its scope is to the highest degree indefinite. Already in 1850 d’Orbigny united it with Phyll. infundibulum d’Orb. sp., and Pictet joined in this opinion. Tietze, Uhlig, N. I. Karakasch, and Kilian (at first) spoke against such a union. In more recent times Kilian came to the conviction that Phyll. Rouyanum represents the young whorls of various species of Phylloceras, chiefly Phyll. Eichwaldi Karakasch and Phylloceras Prendeli Karakasch. Having only 1 specimen, only 12 mm in diamet—

... I do not consider it possible to enter into the substance of these disagreements. Another question connected with the understanding of the species under consideration consists in what is represented by the Indian form described under the same name (Stoliczka. Cretaceous of Southern India; p. 117; pl. LIX, fig. 5–7). This form was already given by d’Orbigny (Prodrome II; p. 213; ét. 22. Sénonien, No. 45) the name Amm. Forbesianus, and under this same name it was described again by Kossmat (Südindische Kreidef. I; S. 109; Taf. XV. Fig. 1). Later Kossmat divided it into two species: Phylloceras Forbesianum and Phylloceras Whiteavesi (Südindische Kreidef. III; S. 124). On comparison with figures of suitable size I could not discover essential differences between Phyll. Rouyanum and Phylloceras Whiteavesi Kossm., but, taking into account the high stratigraphic position of the Indian form, I am inclined to think that they represent different species.

Locality. Khodzhal’-Makha, from concretions in Aptian clay No. 8 (1 specimen).

Distribution. Aptian deposits of southern France, Austria, Switzerland, and the Caucasus. It has also been cited from Albian and Neocomian deposits.

111. Phylloceras Guettardi Raspail. Sp. 1831.

1. Ammonites Guettardi. D’Orbigny. Terr. Crét I; p. 169; pl. 53, fig. 1–3.

2. Ammonites Guettardi. Quenstedt. Cephalopoden; S. 265; Taf. 20, Fig. 2.

3. Ammonites Guettardi. D’Orbigny. Prodrome II; p. 114; ét. 18, Aptien, No. 31.

4. Ammonites Guettardi. Pictet, et Campiche. Sainte Croix I; p. 347.

5. Phylloceras Guettardi. Kilian. Montagne de Lure II; p. 9.

6. Phylloceras Guettardi. Anthula. Kreidefossilien v. Kaukasus; S. 97; Taf. I, Fig. 5.

7. Phylloceras Guettardi. Jacob. Clausages; p. 401.

8. Phylloceras Guettardi. Jacob et Tobler. Engelberger Aa; p. 8.

9. Phylloceras Guettardi. Kilian. Lethaea geognostica; Taf. 8, Fig. 6.

Three specimens show the characters of this species, i.e., possessing a similar cross-section of the whorls and a narrow umbilicus, they bear characteristic constrictions and thin ribs when the shell is preserved. The lobe line is also similar to that figured by d’Orbigny. The siphonal side is somewhat less evenly rounded than it is shown by d’Orbigny, but is similar to the figures...

Quenstedt and Anthula. Anthula depicts a suture line differing both from that figured by d’Orbigny and from that observed on my specimens, in having smaller and less distinctly leaf-like saddle endings. It seems to me that this difference should be attributed to the imperfection of the illustration.

Locality. Lavashi, in a gray sandy marl, No. 1 (3 specimens).

Distribution. This species occurs in the Aptian deposits of France, North America, Tyrol, the Balkan Peninsula, and the Caucasus.

112. Phylloceras Morelianum. D’Orbigny sp. 1840.

1. Ammonites Morelianus. D’Orbigny. Terr. Crét. I; p. 176; pl. 54, fig. 1–3.

2. Ammonites Thetys (pars). Pictet et Loriol. Voirons; p. 17.

3. Ammonites Morelianus. Pictet et Campiche. Sainte. Croix I p. 348.

4. Phylloceras Thetys Kilian. Montagne de Lure II; p. 30 (non Phyll. Thethys in Montagne de Lure I).

Numerical data.

	In millim.	Rel. to diam. of shell.	Rel. to thickness of corresponding whorl.
Diameter of shell	27	1.00	—
Diameter of umbilicus	3	0.11	—
Last whorl.
Height above the suture	15	0.56	1.67
Height above preceding whorl	—	—	—
Thickness	9	0.33	1.00

A flat, discoid shell with high and thin involute whorls, having a somewhat narrowed siphonal side. The sculpture consists of very fine riblets, up to 20 per 1 cm. The suture line is finely incised, has large leaf-like saddle endings and long and narrow lobe endings.

Similarities and differences. Most authors unite Phylloceras Morelianum with Phylloceras Thetys d’Orbigny. D’Orbigny himself, who described Phyll. Morelianum in “Paléontologie Française,” no longer returns to this form in the “Prodrome.” The differences from Phyll. Thetys indicated in “Paléontologie Française” amount to a shorter siphonal lobe, a simple instead of a double terminal leaflet of the outer saddle, and a more branched first lateral lobe. All

these differences are also observed in my specimen. On this basis, and taking into account that Phyll. Thetys is a Neocomian form, whereas Phyll. Morelianum is Aptian, I prefer to regard Phyll. Morelianum as an independent species.

Locality. Khojal-Makhi (1 specimen), probably from concretions in the Aptian clay.

Distribution. Aptian deposits of southern France.

113. Phylloceras aff. Velledae Michelin sp. 1834.

(Table VII, fig. 99).

1. Ammonites Velledae. Michelin. Argile dépend. du Gault; p. 100.
2. Ammonites Velledae. D’Orbigny. Terr. Crét. I; p. 280; pl. 82.
3. Ammonites. Velledae. Leymerie. Aube; p. 33.
4. Ammonites Velledae. D’Orbigny. Prodrome II; p. 124; ét. 19; Albien, No. 34.
5. Ammonites Velledae. Pictet et Campiche. Sainte Croix I; 268; pl. XXXVI, fig. 8.
6. Ammonites Velledae. Stoliczka. Cretaceous of Southern India, p. 116; pl. LIX, fig. 1—4.
7. Ammonites Velledae. Tietze. Ammoniten v. Swinitza; S. 134.
8. Ammonites Velledae. Schmidt. Sachalin; S. 10, Taf. I, Fig. 3—4.
9. Phylloceras Velledae. Yokogama. Japanisches Kreide; S. 177 Taf. XIX, Fig. 1.
10. Phylloceras Velledae. Kossmat. Südindische Kreidef. I; S. 108. Taf. XV, fig. 3.
11. Phylloceras Velledae. Parona e Bonarelli. Fossili Albiani; p. 77.
12. Phylloceras Thetys. Karakash. Cretaceous deposits of the Caucasus; p. 12; table IV, fig. 13.
13. Phylloceras Velledae. Anthula. Kreidefossilien v. Kaukasus; S. 95; Taf. V, Fig. 1.
14. Phylloceras ex aff. Velledae. Anthula. Ibidem; S. 96, Taf. V. Fig. 2
15. Phylloceras Velledae. Jacob. Clausages, 401.
16. Phylloceras ex aff. Velledae. Jacob. Engelberger Aa, p. 8.
17. Phylloceras Velledae. Sommermeier. Aptien und Albien v. Peru. S. 370.

The specimens are fairly close to d’Orbigny’s figures. The transverse section of the whorls has the same ratio of height to thickness, but is somewhat less narrowed toward the siphonal side. The sinuousness of the striae on the shell is always observed, though to varying degrees. The sutural line, apart from age-related differences, is similar. The general impression is one of close similarity, but not complete

identity. The form described here shows a closer resemblance to Phyll. Velledae, figured by Anthula (l. c.), and to Phylloceras Thetys of N. I. Karakash, and is probably quite identical with the form that served as the basis for the descriptions of these two investigators. From Phylloceras ex aff. Velledae of Anthula most of my specimens differ in having less thick whorls; one specimen in this respect approaches Anthula’s form, but differs in the simpler form of the siphonal saddle and the larger leaf-like endings of the remaining saddles. Which of these differences should be attributed to age and to the imperfection of the drawing, and which to specific distinction, is difficult to say.

Locality. Khodzhal-Makha (5 specimens), probably from concretions in Aptian clay.

Distribution. Phyll. Velledae is a widely distributed Albian form. Ammonites from the Aptian deposits of the Banat and the Caucasus (Tietze, Anthula, Karakash, Alich, Simonovich) might be referred to the described form. It is probably not identical with Phyll. Velledae, but, given the diversity of forms described and figured under this latter name, I cannot establish definite distinguishing characters for the Aptian form.

114. Phylloceras Anthula n. sp.

1. Phyll. subalpinum. Anthula. Kreidefossilien v. Kaukasus; S. 96: Taf. V, Fig. 3—4.

Numerical data.

Specimens	I	II	I	II	I	II
	in millim.	in millim.	Ratio to shell diam.	Ratio to shell diam.	Ratio to whorl thickness	Ratio to whorl thickness
Diameter of shell	30	39	1·00	1·00	—	—
Diameter of umbilicus	2	2	0·07	0·05	—	—
Last whorl.
Height above suture	17	22	0·57	0·57	1·21	1·22
Height above preceding whorl	12	16	0·40	0·41	0·86	0·89
Thickness	14	18	0·47	0·46	1·00	1·00
Penultimate whorl.
Height above suture	8	11	0·27	0·28	1·14	1·10
Thickness	7	10	0·23	0·26	1·00	1·00

An involute form with moderately high whorls and a funnel-shaped umbilicus. The cross-section of the whorls is oval, slightly narrowed toward the siphonal side. The sculpture consists of striae spaced 0.5–1 mm apart; these striae are weak and are not at all noticeable near the umbilicus. The lobate line is rather complex and differs from Anthula’s figure in having somewhat narrower lobes. The number of auxiliary lobes is five.

Similarities and differences. From Phyll. subalpinum d’Orb. sp. (Terr. Crét; p. 283; pl. 83, fig. 1–3, under the name Ammonites Alpinus) it differs in appreciably lower whorls (the ratio of height to thickness in my specimens is 1:21 and 1:22; in Anthula 1:29 in the text; 1:24 in the figure; in d’Orbigny, des Amm. Subalpinus—140). Correspondingly, Phyll. subalpinum has more auxiliary lobes. These differences, although small, are in my view sufficient to separate the Aptian form from the Albian one.

Locality. Khodzhal-Makha (3 specimens) from concretions in the Aptian clay.

Distribution. Aptian deposits of the Caucasus.

Order Nautiloidea.

family Nautilidae.

genus Nautilus Breynius 1732 (Linnaeus 1768).

115. Nautilus Neckerianus Pictet 1847.

1. Nautilus radiatus. Forbes. Lower greensand fossils; p. 353.
2. Nautilus Neckerianus. D’Orbigny. Prodrome II; p. 122; ét. 19. Albien, No. 6.
3. Nautilus Neckerianus. Pictet et Renevier. Perte du Rhône, p. 21.
4. Nautilus Neckerianus. Pictet et Campiche. Sainte Croix I; p. 152; pl. XVI.
5. Nautilus Neckerianus. Anthula. Kreidefossilien v. Kaukasus; S. 94.
6. Nautilus Neckerianus. Jacob et Tobler. Engelberger Aa; p. 7.

Quite numerous specimens appear to be close to this species in sculpture and lobate line. The sculpture, as in Nautilus Neckerianus, consists of broad, flat ribs, while the furrows separating these ribs are alternately shorter and longer. The position of the siphon differs somewhat from the type, corresponding more closely to what is observed in Naut. neocomiensis d’Orb. But since in my specimens this position is rather variable, and the sculpture and lobate line correspond exactly to Naut. Neckerianus, I do not venture to separate the Caucasian—

form of this species, in relation to which it is a somewhat more ancient mutation.

Occurrence. Lavashi, in gray sandy marl No. 1 (20 specimens); between Dzhunsuta and Lavashi, in yellowish-gray marl No. 2 (1 specimen); Khodzhal-Makhi (2 specimens), probably from concretions in Aptian clay; Shakh-Dag, in gray sandy marl (1 specimen).

Distribution: Aptian and predominantly Upper Aptian deposits of England, France, Switzerland, northern Germany, and the Caucasus.

116. Nautilus sp.

Indeterminable fragments of smooth internal molds of a form probably belonging to the group Nautili laevigati.

Occurrence. Saltinskaya station, in gray sandy marl No. 3.

Explanation of the Plates

Explication des planches.

Plate I.

1. Belemnopsis minimus List., sp. Gergebil No. 2.

2. Belemnopsis aptiensis Stoll. sp. a from the ventral side; b from the side. Lavashi No. 5.

3. Belemnopsis aptiensis Stoll. sp., transverse section. Lavashi No. 5.

4. Scaphites sp. Gergebil No. 2.

5. Bochianites? sp. 1. a from the antisiphonal side; b from the siphonal side; c from the left side. Lavashi No. 1.

6. Bochianites? sp. 2. Tsudakhar Fi.

7. Crioceras n. f. ind. a from the side; b transverse section. Khodzhal-Makha.

8. Crioceras caucasicum n. sp. a from the side; b from the siphonal side; c transverse section. Lavashi No. 1.

9. Crioceras caucasicum n. sp. a from the side; b from the antisiphonal side; c from the siphonal side; d transverse section. Khodzhal-Makha.

10. Crioceras aff. ramososeptatum Anth. a from the right side; b from the left side; c from the siphonal side; d transverse section. Khodzhal-Makha.

11. Crioceras sp. ind. 1. Gergebil No. 2.

12. Crioceras aff. dissimile d’Orb. sp. a from the side; b from the antisiphonal side; c from the siphonal side. Tsudakhar No. 4 b.

13. Crioceras aff. dissimile d’Orb. sp. a from the side; b from the siphonal side. Tsudakhar No. 4 b.

II

1. Crioceras sp. ind. 2. a from the side; b from the antisiphonal side; c transverse section. Lavashi No. 1.

2. Crioceras cf. undosum v. Koen. sp. a from the side; b from the antisiphonal side; c transverse section. Lavashi No. 1.

3. Crioceras cf. Blancheti Pict. et Camp. sp. a from the side; b from the siphonal side; c transverse section. Khodzhal-Makha.

4. Crioceras sp. ind. 3. a from the side; b from the antisiphonal side; c from the siphonal side. Tsudakhar.

5. Crioceras sp. ind. 4. a from the antisiphonal side; b from the siphonal side. Lavashi.

6. Crioceras sp. ind. 5. a from the side; b from the antisiphonal side; c from the siphonal side. Gergebil No. 5.

Plate II

1. Crioceras sp. ind. 6. Khodzhal-Makha.

2. Acanthoceras sp. Gergebil No. 5.

22–25. Douvilleiceras Martini d’Orb. sp. a from the side; b from the siphonal side; c from the front. Khodzhal-Makha.

26–29. Douvilleiceras Stuckenbergii n. sp. a from the side; b from the siphonal side; c from the front. Khodzhal-Makha.

30–32. Douvilleiceras pusillum n. sp. a from the side; b from the siphonal side; c from the front. Khodzhal-Makha.

33–36. Douvilleiceras intermedium n. sp. a from the side; b from the siphonal side; c from the front. Khodzhal-Makha.

37–38. Douvilleiceras Waageni Anth. sp. a from the side; b from the siphonal side; c transverse section. Khodzhal-Makha.

Plate III

1. Douvilleiceras aff. Meyendorffi Sinz. a from the side; b from the siphonal side; c from the front. Khodzhal-Makha.

III

40–41. Douvilleiceras Cornuelianum d’Orb. sp. a lateral view; b from the siphonal side; c from the front. Lavashi No. 1.

42–43. Douvilleiceras seminodosum Sinzow. a lateral view; b from the siphonal side; c from the front. Lavashi No. 1.

1. Douvilleiceras sp. ind. 1. Lavashi No. 1.

2. Douvilleiceras sp. ind. 2. a lateral view; b from the siphonal side. Tsudakhar No. 4 b.

3. Douvilleiceras sp. ind. 3. a lateral view; b from the siphonal side; c transverse section. Lavashi No. 1.

4. Acanthohoplites Aschiltaensis Anth. sp. a lateral view; b from the siphonal side; c from the front. Khodzhal-Makha.

5. Acanthohoplites aplanatus n. sp. a lateral view; b from the siphonal side; c from the front. Khodzhal-Makha.

49–50. Acanthohoplites Tobleri Jacob. sp. a lateral view; b from the siphonal side; c from the front. Khodzhal-Makha.

1. Acanthohoplites sub-Tobleri n. sp. a lateral view; b from the siphonal side; c from the front. Khodzhal-Makha.

52–55. Acanthohoplites Sinzowi n. sp. a lateral view; b from the siphonal side; c from the front. Khodzhal-Makha.

56–58. Acanthohoplites sub-Tobleri n. sp. a lateral view; b from the siphonal side; c from the front.
56—Lavashi; 57–58. Khodzhal-Makha.

Plate IV

1. Acanthohoplites n. f. cf. Tobleri Jacob. sp. a lateral view; b from the siphonal side; c from the front. Khodzhal-Makha.

60–61. Acanthohoplites planidorsatus n. sp. a lateral view; b from the siphonal side; c from the front. Khodzhal-Makha.

62–63. Acanthohoplites rectangularis n. sp. a lateral view; b from the siphonal [[unclear: continuation cut off at bottom of page]].

IV

...side; from the front. Khodzhal-Makha.

1. Acanthohoplites quadratus n. sp. a from the side; b from the siphonal side; c from the front. Khodzhal-Makha.

2. Acanthohoplites aff. Trantscholdi Sim. Bac., Sor. sp. a from the side; b from the siphonal side; c from the front. Khodzhal-Makha.

66–67. Acanthohoplites subangulicostatus Sinz. a from the side; b from the siphonal side; c from the front. Khodzhal-Makha.

1. Acanthohoplites stephanoides n. sp. a from the side; b from the front. Khodzhal-Makha.

Plate V.

1. Acanthohoplites stephanoides n. sp. a from the side; b from the siphonal side; c from the front. Khodzhal-Makha.

2. Acanthohoplites Anthulai n. sp. a from the side; b from the siphonal side; c from the front. Khodzhal-Makha.

3. Acanthohoplites Uhligi Anth. sp. a from the side; b from the siphonal side; c from the front. Khodzhal-Makha.

4. Acanthohoplites Uhligi Anth. sp. a from the side; b from the front. Zudakhar No. 1.

73–75. Acanthohoplites compressus n. sp. a from the side; b from the siphonal side; c from the front. Khodzhal-Makha.

76–78. Parahoplites Melchioris Anth. a from the side; b from the siphonal side; c from the front. Khodzhal-Makha.

Plate VI.

1. Parahoplites Melchioris. Anth. a from the side; b from the siphonal side; c from the front. Khodzhal-Makha.

2. Hoplites sp. Kaka-Makha.

81–83. Hoplites (Deshayesites) Deshayesi Leym. sp. a from the side; b ...

V

from the siphonal side; c from the front. Tsudakhar.

1. Hoplites (Deshayesites) consobrinus d’Orb. sp. a from the side; b from the siphonal side; c from the front. Lavachi No. 1.

2. Hoplites (Deshayesites) n. f. aff. Weissi Neum. et Uhl. a from the side; b from the siphonal side; c from the front. Tsudakhar No. 1.

86–87. Hoplites (Deshayesites) Lavaschensis n. sp. a from the side; b from the siphonal side; c from the front. Tsudakhar.

88–91. Hoplites (Deshayesites) furcatus Sow. sp. a from the side; b from the siphonal side; c from the front. Lavachi No. 1.

Plate VII.

92–93. Hoplites (Deshayesites) subfurcatus n. sp. a from the side; b from the siphonal side; c from the front. Lavachi No. 1.

94–95. Desmoceras Saltense n. sp. a from the side; b from the siphonal side; c from the front. Khodzhal-Maka.

1. Puzosia (Latidorsella) aff. latidorsata Mich. sp. a from the side; b from the siphonal side; c from the front. Khodzhal-Maka.

2. Baculites? sp. Gergebil No. 2.

3. Turrilites aff. elegans d’Orb. a from the side; b from the siphonal side; c from the front. Lavachi No. 4.

4. Phylloceras aff. Velledae Mich. sp. a from the side; b from the siphonal side; c from the front. Khodzhal-Maka.

100–101. Hoplites (Deshayesites) Deshayesi Leym. sp. a from the side; b from the siphonal side; c from the front. Khodzhal-Maka.

Plate I.

Visible specimen plate with handwritten specimen labels (numbers and letters) throughout.

Photo by P. Ivanov.

Plate III

Phot. A. Pakhom.

Visible figure labels on the plate include: 40, 41, 44, 45, 46, 48, 49, 50, 51, 52, 53, 54, 55, 56, with sublabels such as a, b, c, and d adjacent to individual specimens.

Plate IV.

Photo by P. Pavlov.

Plate V.

Photo by P. Pavlov.

Plate VI

Handwritten specimen labels visible on the plate include: 79a, 79b, 79c; 80; 81a, 81b; 85; 86; 87; 88; 89a, 89b, 89c; 90a, 90b, 90c; 91a, 91b, 91c.

Photo by N. Pavlov.

Plate VII.

Phot. P. Pavlova.