K. B. Radugin.

COELENTERATA OF THE MIDDLE DEVONIAN IN THE VICINITY OF THE VILLAGE OF LEBEDYANSKOYE

I. INTRODUCTION.

The Anzhero-Sudzhensk district of the Kuznetsk Basin, because of its great practical and scientific interest, has been visited fairly often by geologists, who collected—among other things—paleontological material, especially Devonian, in the vicinity of the village of Lebedyanskoye. Given the striking richness of the fauna observed there, it is natural that, as a result of these collections, a rather large amount of raw material accumulated in Tomsk. The task of the present work was to process this material, namely that portion of it which pertains to stromatoporoids and corals, with the ultimate aim of studying the stratigraphy of the margins of the Kuznetsk Basin.

The execution of the task set encountered considerable difficulties. These, however, were not at all connected with the material conditions under which the work was carried out. On the contrary, the latter fully ensured the success of the work. The difficulties lay in the state in which the study of corals in general now finds itself, and in particular the study of them in the Kuznetsk Basin, where it is only beginning. Where corals have been well studied, there a sharp turning point—or rather a leap forward—is taking shape in the methods of their study¹. Siberian material, even if studied with partial application of this new methodology, naturally proves difficult to compare with previously described forms. This difficulty is intensified by the circumstance that comparisons must be made with forms from extremely remote localities (Western Europe, America), since in the Urals and in Turkestan precisely the corals have been almost entirely unstudied. Under such conditions, it is natural that corals—especially prone, because of their attached mode of life, to produce local varieties—corals from such a remote locality as the Kuznetsk Basin yield peculiar series of forms. Because of necessity, these new forms have to be distinguished, as a working hypothesis, as new species.

As for the new methods of work, given the brief time that could be devoted to this relatively narrow topic, it was not always possible to carry them out sufficiently. Nevertheless, insofar as possible, serial transverse sections were made, which Prof. M. K. Korovin widely used in preparing the material for the work, and the study of very closely spaced and numerous sections of the young stages of corals, as well as the study of their reproduction, was undertaken. In studying individual species I always tried to determine the changes in their properties with age, both of individual corallites and of the coral itself (in compound forms).

The material for the present work was a collection preserved in the cabinet of Prof. M. K. Korovin. This collection was collected chiefly by him in 1916 and 1917. To this main—

Proceedings of TII, vol. 56, issue VI, no. 4.

to parts of the collection have been added earlier collections made by Prof. M. E. Yanishevsky and T. Smirnov, as well as by Prof. M. A. Usov. Finally, quite sporadically the collection contains specimens delivered by student trainees. The collection is distinguished by excellent preservation, as was already noted in the work cited below by Prof. M. K. Korovin, who carried out the first preparatory work on the study of the Lebedyanskoye corals.^1) During the present work, which is its completion, the existing thin sections were studied, and new ones were also ordered. The latter were made by the preparator M. F. Kapranov. The specimens that in the present work were chosen as holotypes and plesiotypes have been separated from the general collection into individual trays and marked with the provisional numbers given in their proper place in the description. All photographs and drawings were made precisely from the holotypes and plesiotypes.

The result of the work is, above all, a rather extensive descriptive material, encompassing 49 forms; even this material in itself represents a certain scientific value; but the present work also has practical significance, in particular for the stratigraphy of the Kuznetsk Basin, about which it is appropriate to speak in greater detail in the conclusion.

II. REVIEW OF PREVIOUS INVESTIGATIONS

The first information on the Coelenterata from Lebedyanskoye is found in the preliminary report of Prof. A. Zaitsev, “Geological investigations of 1894 along the line of the Siberian Railway, between the Tom River and the town of Achinsk, and in the basins of the Ya and Kiya rivers” (Geological investigations and reconnaissance works along the line of the Siberian Railway, issue I, 1896). There, on p. 66, Acervularia sp. is mentioned from an outcrop along the Mazalovsky Kitat, 2.5 versts above the coal deposit, and 2 versts below the village of Lebedyanskoye Zaitsev observed Favosites sp. and Stromatopora sp.^2)

It is interesting to note that the limestones of the village of Lebedyanskoye were then considered Carboniferous. In an article by the same A. Zaitsev, printed in 1895 in vol. IV of the Vestnik Zolotopromyshlennosti (pp. 346, 368, and 392) and entitled “On the question of deposits of useful minerals in the region of the Siberian Railway,” we find, in addition to the data cited above, another indication of Favosites sp. along the Alchedat River, 1½ v. from its mouth.^3)

Then Krasnopolsky, in a preliminary report on geological investigations in 1896, cites Favosites cervicornis, Favosites sp., and Cyathophyllum coespitosum Goldf. from an outcrop along the Alchedat River within the limits of the village of Lebedyanskoye, and along the Mazalovsky Kitat River, 1 v. below the mill—Favosites sp. and Acervularia sp.; moreover, he determined there the dip of the beds as 3 under an angle of 40°.

In 1927 there appeared “An outline of the geological structure and useful minerals of the Tomsk District”—a report by Prof. M. K. Korovin on investigations carried out by him. In this, thus far the only major work on the geology of the Tomsk District, we find indications of the presence in the Devonian of the village of Lebedyanskoye of the following forms, originating specifically from the Mazalovsky Kitat River below Alchedat: Cyathophyllum

^1) In doing so, he prepared a large amount of material and made numerous serial sections and measurements, which have been used here in their entirety.

^2) In both cases a steep NW dip of the beds was noted.

^3) Here the beds dip at an azimuth of 250° at an angle of 20–25°.

hexagonum and Cyathophyllum coespitosum, as well as the components of reef limestones Favosites, Pachypora, Alveolites, and Stromatoporoidea. Reef limestones have also been noted near the Shcherbinovskaya mine.

Finally, in V. I. Yavorsky’s recently published work, “Actinostromidae from the Devonian deposits of the margins of the Kuznetsk Basin and the Urals” (Izvestiya of the Main Geological Prospecting Administration, vol. XLIX, no. 4, 1930), the species Actinostroma verrucosum Gdf. is described, among others, as having been found also along the Alchedat River.

This exhausts all the published data on the Coelenterata of the village of Lebedyanskoye.

III. COMPOSITION AND STRUCTURE OF THE DEVONIAN OF THE VILLAGE OF LEBEDYANSKOYE

During the work of the Tomsk geological party in the summers of 1929 and 1928, I obtained, in the region of the village of Lebedyanskoye, rather interesting material, although still far from sufficient for the study of this very complex area. Part of this material, concerning the Devonian of the village of Lebedyanskoye, is presented below, in particular on the appended drawing (Fig. 1).

This drawing shows how complex the geological structure is of the cover thrust over the productive series and composed of limestones, marly and clayey shales, as well as calcareous sandstones. The six faults shown on the map by no means exhaust all those observed. And how many more may be hidden beneath the deposits!

Even the folding of the Lebedyanskoye district is sufficiently complex, for—as shown in Fig. 1—in the section along the Alchedat River we have at least three anticlines; moreover, in one place (outcrop 3093) even overturned bedding of the strata was recorded. This was established from the position of coral stalks, which in the quarry are situated with their upper, younger ends downward from the surface of the beds.

The large number of faults—some bedding-plane faults, others dipping more steeply than the strata—clearly shows that the structure of the cover in the section along the Alchedat River is undoubtedly imbricate. Hence it is understandable how complex the tectonic and stratigraphic relationships are within the Lebedyanskoye Devonian. Here only the joint work of a tectonic geologist and a paleontologist, with bed-by-bed collecting and study of the fauna, can provide a clear picture and exhaustive results. Such work—incidentally—should be begun precisely with the meridional segment of the Alchedat River, where we have normal overthrusting of marly bryozoan-brachiopod beds upon massive coral limestones. Here a series of beds about 40–50 m thick is exposed. The lower horizons of this series—the coral limestones—abound in large massive stalks of Favosites. It is precisely here that Cystiphyllum senecaense (?) Bill. occurs, apparently indicating lower horizons of the Middle Devonian. Since the horizon with Cystiphyllum senecaense (?) Bill. is not repeated anywhere else either along the Alchedat or along the Mazalovsky Kitat and occurs in the closure of an anticline, it is natural to regard this horizon as the most ancient; moreover, the beds with Spir. cheechiel evidently belong precisely to the marly horizons lying above.

Such are the conclusions concerning the stratigraphic relationships within the Lebedyanskoye Devonian, and until bed-by-bed collection and study of its fauna have been carried out, we must limit ourselves to these.

IV. DESCRIPTION OF SPECIES

RUGOSA.

1. Amplexus altaicus var. minor n. var.

(Plate I, fig. 1).

In the collection studied, the number a13 designates the holotype of the given species, with traces of growth and very weakly expressed costae; its height is 5 cm, and the diameter of the calyx is 36–41 mm. The depth of the calyx, apparently, was not less than 25 mm.

The number of septa (of the 1st and 2nd orders) in the calyx is 86.

The length of the septa of the 1st order in the calyx is 5–6 mm (twice as great as that of the septa of the 2nd order).

The tabulae are curved, partly complete, partly incomplete, i.e., resting upon the tabulae lying below. The average distance between them is 3 mm. The ends of the septa are apparently entire, without spines, unlike Amplexus altaicus Dyb., to which the species described is rather close and of one of whose mutational branches it probably represents. In diameter the species described is close to the Silurian Calophyllum darcoceros Dyb., but differs from it in the smaller number of septa (86 instead of 100–124), as also from Ampl. incondita Bill.

The holotype a13 comes from the vicinity of the village of Lebedyanskoye, where it was found by Prof. M. E. Yanishevsky and Smirnov.

2. Amplexus inconditus (?) Bill.

1. Amplexus incondita. 2, p. 7, tab. 1, fig. 1, 1a, 1b.

External structure. This species is represented by a fragment of conical form, a11, selected as the plesiotype; its upper section has diameters of 47 and 51 mm, and the lower one—32.5 and 36 mm. The height of the fragment is 30–33 mm. The height of the corallum was probably not less than 75 mm. On the surface of the corallum costae are visible, as well as growth striae and wrinkles, in one place drawn downward in funnel-like fashion toward a root-like projection of the epitheca.

Internal structure—usual for the genus Amplexus. In the lower section there are 96 septa of the 1st and 2nd orders, and in the upper—110 septa; in the available transverse thin section, with diameters of 24 and 33 mm, this number is approximately 60.

A fossula is evidently associated with the above-mentioned projection of the epitheca. In the available thin section this place appears as shown in fig. 2. Thus the fossula, expressed as a depression of a tabula, apparently contains 3 septa of the 1st order and 2 septa of the 2nd order.

The length of the septa of the 1st order in the thin section is 7–8 mm, in the section with a diameter of 32.5–36 mm—4.5–6 mm, and in the section with a diameter of 47–51 mm—3–5 mm. Thus, a reduction in the length of the septa with the growth of the corallum is clearly expressed. In the two upper sections the fossula is not perceptible.

Closest to the form described stands Amplexus inconditus Bill. However, as is often the case when comparing with very long-established species, this comparison is made difficult by their insufficient study, all the more so since we do not have a longitudinal section of the Lebedyanskoye form.

The plesiotype described above comes from the vicinity of the village of Lebedyanskoye, whence it was delivered by Prof. Yanishevsky and Smirnov.

3. Aulophyllum (Duncania?) sp.

(Plate I, fig. 30; pl. II, fig. 8)

In the collection described there is, from the village of Lebedyanskoye, only one thin section—an incomplete transverse section of a coral (thin section a15), illustrating the internal structure of this species and representing its holotype. Unfortunately, the coral itself has not been preserved. The diameters of the latter were no less than the diameters of the available transverse section, equal to 8.5 and 9.5 mm. The wall is thick, about 1 mm in thickness. In addition to the outer wall there is also an inner wall with a concentric microstructure; the latter separates, in the section, a central area without septa, of irregularly elliptical shape, with diameters of 1.5 mm and 1.75 mm.

Between the walls are situated 26 septa of the first order, merging with the inner wall and also with one another, not reaching, approximately, \(1/3\) of the distance to it. These septa are very thick; along their axes a thinner central part is visible, thickened by deposits of stereoplasm, just as is shown by Roemer [16, pl. 112, fig. 10], where Aulophyllum (Nicholsonia) bohemicum (Barr.) is illustrated. Besides septa of the first order, there are also septa of the second order, visible in the structure of the exotheca and projecting from it only in the form of blunt denticles or tubercles.

The genus to which the described form belongs cannot be precisely established because of the absence of a longitudinal section. For this very reason it is not clear whether it has tabulae and dissepiments, on the basis of which the genera Aulophyllum Edw. et H. and Duncania Dekon. are distinguished. Incidentally, the genus Laccophyllum, established later by Simpson, coincides, according to the author’s diagnosis, with the genus Aulophyllum Edw. et Haime and therefore is its synonym, as is also the somewhat later established genus Nicholsonia (Alleynia) Roemer, entirely identical with the genus Laccophyllum Simp. The absence of dissepiments in our form might serve as a reason for assigning it to the genus Duncania, developed in the Carboniferous. However, as the already cited fig. 10 of Roemer shows, the section of Aulophyllum (Alleynia) may also be devoid of dissepiments when they are rare. Thus, the question will be settled definitively by additional material. For the time being I assign the described form to Aulophyllum, since in the character of its transverse section it is completely identical with the Devonian A. (Alleynia) bohemicum (Barr.), differing from the latter only in the greater number of septa (in the Bohemian species there are only 30 in all).¹

4. Acervularia davidsoni (?) Edw. et Haime.

(Plate I, fig. 29)

1. Acervularia davidsoni. 3, p. 418, pl. 9, figs. 4, 4a, 4b.

External structure. As the plesiotype of this species there was selected specimen a84—a massive stock about 9–10 cm high and 20 cm in diameter, originating from the vicinity of the village of Lebedyanskoye. The diagonal of the corallites varies from 7 mm to 15 mm (12–13 mm on average in adults), and on 1 cm² of surface there are 1–1.4 corallites. The diameter of the calice is 4–6 mm, and the depth 2–3 mm.

¹ A. bohemicum (Barr.) occurs in G and H (\(D_1^2—D_2^2\)).

The internal structure was studied from 4 successive transverse sections and one longitudinal polished section. In the transverse sections the dependence of the number \((u)\) of septa on the size of the mean diagonal \((d)\) of the corallite is clearly visible; thus at \(d = 9\text{–}10\) mm, \(u = 36\text{–}38\), and at \(d = 11\text{–}12\) mm, \(u = 40\text{–}42\), and 46 at \(d = 13.3\) mm.

The septa, on which clearly expressed carinae are present, are of two orders. The septa of the 1st order reach the center, whereas the septa of the 2nd order reach only as far as the zone of thickening of the dissepiments, sometimes passing to the inner margin of this zone. The septa of the 1st order are straight, as are the septa of the 2nd order; the former thicken sharply in the zone of thickened dissepiments, which in general is distinguished by a strong development of stereoplasm.

Between the septa the radius intersects from 6 to 16 dissepiments. The internal diameter of the zone of development of stereoplasm is equal to 3.5–6 mm, coinciding with the diameter of the calice. Dissepiments are also observed within this zone.

In the longitudinal polished section, peripheral zones of horizontal vesicles are clearly indicated. Then come zones of steeply falling vesicles. Within them the inner wall is also developed at the expense of stereoplasm deposits. The central zone is characterized by tabulae, convex upward, frequent and incomplete, intersecting with the septa. The width of this zone is 2–2.5 mm. The distance between the tabulae is about \(1/3\) mm. Their upward rise is explained by the presence of a central elevation on the bottom of the calice.

Since the author’s diagnosis and figures of A. davidsoni almost coincide with the description given above, our determination may be regarded as close to reality. True, the internal structure remained without comparison.

Simpson (21, 218), on the basis of American representatives of this species, established the genus Prismatophyllum, and considered carinae characteristic of it, while denying the presence of an inner wall in A. davidsoni. Since the originals of Edw. et Haime were not investigated in this connection, it seems to me that the diagnosis of the French authors’ species retains its force. At the same time it should be noted that the American representatives of A. davidsoni (Prismatophyllum davidsoni) differ from the Lebedyanskaya form also in the character of the tabulae.

5. Cyathophyllum (?) sp.

(Table I, figs. 12, 14, 24.)

This species is represented only by 4 transverse polished sections, which may temporarily serve as the holotype; 2 of them cut the calice, the 3rd was made near its bottom, and the 4th below the bottom. The height of the corallum is unknown.

The external diameter of the calice of this coral is 21–24 mm; in a section with such a diameter, and also at a diameter of 20–21½ mm, there are counted in all 74 septa of the 1st and 2nd orders, the latter being only slightly (by ¼–1 mm) shorter and thinner than the former, whose length is 3–4½ mm. In the same sections, between neighboring septa, there are observed 2 (rarely) to 3–6 comparatively thick dissepiments, usually concave toward the center; the latter form a peripheral zone 1.5–3 mm wide. Owing to the development of sclerenchyma along the inner margin of the dissepiments, a semblance of an inner wall is formed, not continuous around the entire circumference.

The 3rd section, with a diameter of 17–20 mm, reveals a sharp increase in the length of the septa of the 1st order, which leave in the center a free oval space 5–6 mm in diameter. At the same time, upon leaving the zone of septa of the 2nd order, whose length here has changed little (not exceeding 3–4 mm), the septa of the 1st order are sharply thickened. Their ends are bent. In connection with this, and with the development of sclerenchyma at the ends of the septa of the 2nd order, an inner wall of complex structure is formed there. The number of dissepiments between adjacent septa reaches 6–8.

It should also be noted that here the fossula is clearly expressed, owing to the sharp shortening of one of the septa, and, correspondingly, bilateral symmetry is clearly expressed.

Finally, in a section with a diameter of 14–16 mm, almost its entire field is filled with sclerenchyma: only the space between the wall and the first row of dissepiments remains unfilled, as well as, in places, narrow, slit-like, short sectors between the septa. The total number of septa of the 2nd and 1st orders is 69 or 70. The septa of the 1st order reach the center, joining there. The boundaries of the septa are outlined only thanks to their microstructure.

So far as I know, no species close to the one described has been noted in the literature. The holotype comes from the Alchedat River above the village of Lebedyanskoye.

6. Diphyphyllum (?) tetrasticum n. sp.

External structure. The holotype of this species—specimen a3—is characterized by a typical bushy stock, of which there is a fragment about 70 mm high. The density of corallites in a transverse break of the corallum is 0.7–0.9 corallites per 1 cm². Corallites, usually 10–12 mm in diameter, are subcylindrical in form, slightly curved, covered with concentrically wrinkled epitheca. Weakly expressed grooves corresponding to the septa are also visible. No calice is observed.

Internal structure. Septa are of two orders. Their number (u) is 40–46. Septa of the 1st order do not reach the center, leaving there a central space with diameter ($d_1$) from 2.2 to 4.2 mm, depending on the diameter of the corallite ($d$), while the ends of the septa of the 2nd order leave free from them a space with diameter $d_2$. Septa

$d$	9–10.5	9–9.5	12–13	9.5–12.5	11.5–13
$d_1$	2.5–3	2.2–3.3	2.4–4.2	2.5–3.2	—
$u$	40	40	44	44	46?
$d_2$	7–8	5.5–6.5	6–7	5.5–6.5	8–9.5

are arranged radially; they are straight or weakly curved. The ends of the septa of the 1st order are often bent, and the bases thickened, which is especially noticeable in the adult stage, where in places even weakly developed carinae appear in the peripheral zone of the septa under strong thickening. Septa of the 2nd order almost do not leave the zone of dissepiments, ranging in length from 0.5 to 3 mm. Dissepiments

form a series of large peripheral vesicles which, when thickened, form something like an inner wall. In addition to this series, there are smaller vesicles, sometimes incomplete; such vesicles usually number from 1 to 3 between a pair of septa, and, with septa of the 2nd order about 3 mm long, up to 3. On the dissepiments, in places, spines or projections of stereoplasm are visible—as if rudimentary septa of the 3rd order.

In longitudinal section, straight and upward-curved tabulae are visible, often incomplete in the dissepiment zone, i.e. resting on the underlying tabula. The distance between them averages ⅔ mm. Narrow dissepiment zones, 1–1.5 mm wide, consist of 1–2 rows of vesicles. The axes of the latter are inclined to the horizon at an angle of 40–80°; their length and height vary respectively from 0.5 mm to 1.5 mm and from 0.1 mm to 0.4 mm.

The mode of reproduction is intracalycular budding; in this process the maternal cell, disappearing, gives rise to 4 young corallites, rising from its calyx after it has been filled. Besides this mode of combination of corallites, there is probably, in rudimentary degree, connection by means of lateral projections, which in some other species of Diphyphyllum are very sharply expressed; the septa do not continue into such connecting projections. The described mode of reproduction contradicts the definition of the genus Diphyphyllum given by Lambe.

The holotype of this species comes from the 2nd quarry of Shcherbinovka on the Mazal. Kitatva, i.e. from the Devonian outcrops farthest to the N on the right bank of this stream.

7. Diphyphyllum strictum (Edw. et Haime).

1. Eridophyllum strictum, 8, p. 424, pl. 8, fig. 7.
2. Diphyphyllum ” Lambe, 8, p. 160.

The external structure of this coral has been established partly from a fragment of a bushy colony—a92, a plesiotype of the species; in this specimen the subcylindrical corallites have a diameter of 7–8 mm; they number about 2.5 per 1 cm² of transverse section. The surface of the epitheca of the corallites, as usual, is characterized by concentric striae and growth wrinkles. Whether the corallites are connected by lateral offshoots is unknown.

The internal structure is characterized by the presence of 38 (at a diameter of 6.5 mm)—44 (at a diameter of 7–8 mm) septa. The septa of the 1st order, not reaching the center, leave there a space free of them, the diameter of which is usually equal to ⅓ of the diameter of the corallites. The septa of the 2nd order are approximately 3 times shorter than the septa of the 1st order. The septa are almost straight, radial; their bases are slightly thickened. One to two rows of dissepiments, concave toward the center, form a peripheral zone coinciding with the zone of septa of the 2nd order. The longitudinal section reveals horizontal, weakly curved tabulae, with an average distance between them of 0.6 mm, and a two-row zone of vesicles; the vesicles of the outer row are larger and have the arrangement characteristic of Diphyphyllum, consisting as if of horizontal and vertical parts; of these vesicles over 5 mm vertically there are 10–13. Their length is 0.5–0.8 mm, and their height 0.25–0.5 mm. The vesicles of the inner row are smaller; their length is 0.5 mm, and their height 0.3 mm. Both in transverse and in longitudinal section rudimentary carinae are observed, in the form of weak riblets on the

surfaces of the septa (along their periphery), directed inward and gently upward.

The tabulae in this species are sometimes perfectly straight, sometimes weakly curved, and at the periphery are often incomplete. The distance between them varies from 0.1 mm to 1 mm; at the periphery, where incomplete tabulae are frequent, the average distance between the tabulae is somewhat smaller than along the axis of the corallite: 0.4 mm. Thus, although the present form is close to Schlüteria rugosa var. westsibirica, it is nevertheless noticeably distinguished from it by the character of its tabulae. However, upon more detailed study this character may prove to be highly variable, for, at least in places, it is indicated in indistinct form also in the coral described here.

The differences of the described form from D. strictum Edw. et Haime, it seems to me, are not great, and therefore it may be considered a plezionotype of this species. In assigning this form to the genus Diphyphyllum I follow Lambe.

Plezionotype a92 comes from the Mazalovsky Kita River above Shcherbinovka.

8. Campophyllum (Charactophyllum?) dimorphicum n. sp.

(Table I, figs. 11, 13).

External structure. The holotype of this species is a fragment of a solitary coral—a16; its full length was probably not less than 45–50 mm. The form of the coral is a curved, irregular cone. Approximately in the middle of the coral there is a sharp decrease in the transverse section (from a diameter of 25 mm to a diameter of 20 mm), which, however, is not the result of rapid development of a young corallite after intracalicinal budding. The surface of the corallite is covered with concentrically wrinkled and striated epitheca.

Internal structure can partly be observed also on the surface of the coral, where weathering has destroyed the wall. There an interesting change with the age of the coral is observed, namely: before the sharp contraction of it, mentioned above, the septa near the wall are provided with numerous carinae and are thicker than at a later stage, when the septa become thinner and entirely devoid of carinae. A polished transverse section of the lower end, with a diameter of 12–15 mm, reveals 34 septa of the first order; they reach the center and there twist counterclockwise (as viewed from above). The septa of the second order extend only a little beyond the false inner wall, formed partly by thickening of the septa and, chiefly, by deposition of stereoplasm in the peripheral zone of the dissepiments. The width of this zone, bounded inwardly by the endotheca, is 1–2 mm. Carinae, if present in this section, are very weakly developed and inconspicuous, but they appear very clearly somewhat later. The central part within the zone of the septa of the second order is probably occupied by tabulae.

In a transverse thin section made from another specimen of this species, one can see an even earlier stage of development (the diameter of this section is 10.5–11 mm). The periphery, bounded by the inner wall, has a width of 2 mm. The inner wall here is continuous and in its outlines repeats the curves of the dissepiments, concave toward the center. The latter number from 3 to 4 between the walls along the radius. The septa of the second order end at the second wall, and many do not even reach it. The septa of the first order reach or almost reach the center, twisting there. The total number of septa is 60. Carinae are not—

noticeable or very weakly developed. Dissepiments are present in small numbers also in the central zone, but there they evidently correspond to tabulae.

Two more thin sections were made from the same specimen, which show a sharp change in the properties of this species in the adult stage (absence of the second wall and shortening of the septa). One of the sections, 15–16 mm in diameter and with 57 septa, shows a complete absence of the latter in the central region (with a diameter of 7.5–8.5), where there are only tabulae. Septa of the ?th orders. Septa of the first order are 3–4 mm long; septa of the second order are only slightly shorter. The radius intersects 4–6 straight or inwardly concave dissepiments. The carinae are clearly expressed.

The last section, with a diameter of 20–21 mm, is entirely analogous to the preceding one. Only the number of septa here is 78, and the carinae are less noticeable.

Thus, this species characterizes the origin of the genus Campophyllum from forms identical with the genus Cyathophyllum, or rather with the genus Diphyphyllum.

In its character in the adult stage, our species belongs to the group for which Simpson established the genus Charactophyllum. However, the origin of Charactophyllum has not been established by him.

I know of no species at all close to the Lebedyanskoye form described. The exact provenance of holotype a16, found in the area of the village of Lebedyanskoye, is unknown.

9. Phacellophyllum (Diphyphyllum?) cosatum n. sp.

(Tab. I, fig. 23, pl. III, fig. 9).

External structure. This species is represented in the collection studied by only a few fragments, which, however, have a distinctive external appearance with a characteristically sharply ribbed surface. The corallites, forming bushy colonies of unknown size, have an external diameter of about 8 mm. On the surface they are covered with sharply projecting ribs, which correspond not to the interseptal spaces, as is usual in cyathophyllids, but to the septa; these ribs are the outer ends of the septa, projecting by 1/4–1/2 mm, and the microstructure of the septa is visible in them to the very end. Thus, the epitheca here appears to be absent.

Internal structure. In transverse section there are observed 40 radial, straight or slightly curved septa of two orders. The length of the septa of the first order, if their projections are also counted, is 2.2–3.5 mm, and that of the second order is 1–1.5 mm. The diameters of the elliptical area without septa are 1.6 mm and 2.8 mm. The thickness of the septa at their base is 0.15–0.2 (rarely 0.25) mm, and it is greater in the septa of the first order. The septa of the second order almost do not change their thickness to the end, where they break off abruptly. The thickness of the septa of the first order, on the contrary, gradually diminishes to nothing. The surface of the septa in the peripheral zone is ornamented with gentle projections, sometimes having the form of thick spines, representing carinae. Such structures are occasionally observed on the septa of the first order and within the inner wall.

Whereas the outer wall, 0.1–0.55 mm thick, is convex between the septa toward the center, the interseptal portions of the inner wall, conversely, face with their convexity in the opposite direction. The thickness of the inner wall varies from 1 mm to 0.3 mm. This wall undoubtedly represents

as a result of deposition on dissepiments of stereoplasm: in places this substance is distributed over 2–3 and even four dissepiments, and in places, within the wall, the outlines of dissepiments immersed in it are clearly visible. The very form of the wall is predetermined by the form of the dissepiments. Nevertheless, the substance of the inner wall does not differ in any way from the material of the septa, even where the boundary between them, usually absent, is faintly indicated. In this case—incidentally—it is seen that the substance of the inner wall is situated at some distance toward the center and on the septa, thickening them to 0.2–0.27 mm.

In transverse section of the corallites, between both walls, dissepiments are sometimes visible, here and there even arranged parallel to the septa, which would seem to indicate that this species has 2 or more rows of vesicles. However, this is not so, as is revealed by longitudinal section. There it is seen that the vesicular tissue is represented almost everywhere by a single row of extremely strongly convex vesicles; they sometimes represent 3/4 of a circumference and are arranged so that a horizontal section may intersect one vesicle twice. In one place a second row of vesicles, almost filled with stereoplasm, was observed; it is possible that they correspond to the outer wall.

The tabulae sometimes extend from wall to wall, their edges being bent downward, but more often they are incomplete, with the same kind of edges, and quite short in the peripheral zone, at the inner wall. In the latter case they are inclined toward the center. The distance between tabulae varies from 0.2 to 1 mm; on average it is equal to 0.5 mm. The thickness of the tabulae is 0.01–0.05 mm.

Reproduction in D. costatum n. sp. occurs by intracalicinal budding, the mother corallite, disappearing, giving rise to 4 young corallites.

As the holotype of D. costatum n. sp., specimen α88 has been selected. As is evident from the description given above, this species is rather distinctive and is obviously new. If Wedekind’s systematics are applied, then we must assign it to his subfamily Phacellophyllinae and to the genus Phacellophyllum Guerich. As for the genus Diphyphyllum, among its American forms there are undoubtedly some close to Ph. costatum n. sp., but, according to Lambe, these forms are characterized by lateral budding and have no inner wall.

Specimen α88 comes from the quarry above the Shcherbinovskaya mine, at the extreme northern outlet of the Lebedyanskoye Devonian, in which, according to the observations of Prof. M. A. Usov, there is interbedding of coral and partly marly limestones, and where he notes: bryozoans, Alveolites, branching Favositiidae, Cyathophyllidae, flat and tubular-branching Alveolites, Aulopora sp., and others.

10. Spinophyllum (?) sp.

(Pl. I, figs. 21, 22)

External structure. As the holotype of this species, specimen α1 has been selected, originating from the vicinity of the village of Lebedyanskoye. This is a conical, at the top slightly curved coral, which had a height of no less than 26 mm, as could be seen before breakage, and a diameter from 5.3 mm at the lower end to 13 mm at the margin of the calice. On the surface, in places, a very thin, almost smooth epitheca is noticeable; and in places rugae are visible.

The internal structure can be studied from four transverse sections. The change with age of certain characters is characterized by the following table, where \(N\) is the sum of septa of the 1st and 2nd orders, \(d\) is the external diameter of the section in mm, \(d_1\) is the diameter of the central zone without septa, \(d_2\) is the external diameter of the zone between the ends of septa of the 1st and 2nd orders, \(d_3\) is the external diameter of the zone of crowded dissepiments, and \(n\) is the number of dissepiments intersected by the radius.

Growth stages	\(N\)	\(d\)	\(d_1\)	\(d_2\)	\(d_3\)	\(n\)
First stage	48	11—12	2.5—3	5.5—6.5	8—9.5	4—7
Intermediate (2)	48	11.5—12.5	2.5—3	6—6.3	9—9.5	3—6
Intermediate (3)	48	11.6—14	2.8—3	5.5—6.5	9.5—10.5	4—7
Adult (4)	48	12.5—14	3.3—3	6—7.5	11—12?	7—11

In all stages, carinae are observed; they are absent only outside the zone of septa of the 2nd order, where the septa sharply thin out (especially in stage 2). However, in the 1st stage they are present there as well in an incipient state.

The dissepiments are usually concave toward the center; rarely straight, thickened in the zone of septal thickening. In the 1st—3rd stages the dissepiments do not extend beyond the zone of septa of the 1st order, but in the 4th stage this is observed, and there they have the appearance characteristic of incomplete dissepiments. Rarely, dissepiments in the form of a check mark or the letter v are visible there, as well as some that rest entirely upon a single septum.

Septa—of 2 orders. Septa of the first order are spindle-shaped in transverse section, and in the 1st stage are zigzag-shaped because of the sharp development of carinae along the periphery. Sometimes the septa of the 2nd order are also spindle-shaped in the zone of crowding of the dissepiments, but usually they gradually thin out. The septa are predominantly straight or weakly curved. Curvature is often observed at the ends of septa of the 1st order, especially in the 4th stage, which sometimes leads to the joining of the septal ends. The arrangement of the septa is generally bilateral. No fossula is indicated. In the peripheral zone, vesicles filled with sclerenchyma are often encountered.

In view of the fact that this species has been studied incompletely, only in transverse sections, its assignment to the genus Spinophyllum Wdk. is provisional.

11. Schlüteria rugosa var. westsibirica n. var.

External structure. The dimensions and form of this fasciculate coral have not been determined, for the form has been studied from individual scattered corallites originating from the area of the village of Lebedyanskoye. Some of them—a 96—have been selected as the holotype of this variety; these corallites have the form of long cylindrical bodies with a diameter of about 10 mm (9—11 mm).

Externally the corallites are covered with a concentrically wrinkled epitheca, which repeats, together with the corallites, their constrictions and swellings. Longitudinal grooves and ridges corresponding to the septal system are weakly expressed.

Internal structure of the corallites is characterized by the presence of a zone of dissepiments surrounding those located in the center

the tabulae, and rather sharply delimited from them in longitudinal section. In the latter, the vesicles are seen arranged in 1–3 (usually 2) vertical rows. In transverse section, it is sometimes possible to observe, between adjacent septa, even 4 dissepiments corresponding to the vesicles. The length of the vesicles, varying from 0.4 mm to 2¼ mm, averages approximately 1 mm, and their height is 0.1–0.6 mm. The bases of the vesicles are directed either parallel to the wall or dip toward the center at an angle of 70°–90°. Where only one row of vesicles is visible, they are so large that the vesicular zone is no narrower than in places with 2 rows.

The tabulae are very characteristic in this species: in their center a broad depression is observed, separated by a ridge-like annular elevation from the annular depression of the tabulae where they adjoin the dissepiments. The distance between the tabulae varies from hundredths of a millimeter to 2 mm, averaging 0.7 mm.

The septal apparatus is represented by septa of 2 orders. Their total number is 46. The septa of the 2nd order, not extending beyond the vesicular zone, are 1.5–2 mm long, while the septa of the 1st order are 3–4 mm long (at a diameter of 10 mm).

The bases of the septa are wedge-like thickened. Carinae are absent or are indicated as tubercles in transverse section of the septa¹. In transverse section the septa are straight or slightly curved, especially the ends of the long septa, which in one pair even proved to be connected.

Comparison of the form described with Schlüteria rugosa figured by Wedekind (23, 6, figs. 3, 4) shows a considerable similarity between these two corals. However, the lesser development of the interseptal plates and a number of other deviations allow our form to be regarded as a variety of the German one.

The holotype of the species was obtained from the vicinity of the village of Lebedyanskoye.

12. Schlüteria rugosa var. minor n. var.

External structure. The available fragment of a bushy coral—а91, selected as the holotype and coming from the vicinity of the village of Lebedyanskoye, consists of subcylindrical corallites with a diameter of about 8–10 mm; there are about 1.5 (1.1–2) of them per 1 cm². The surface of the corallites, covered with epitheca, is characterized by striae and wrinkles, and in places also by constrictions of growth, as well as by longitudinal grooves opposite the septa; the latter, in transverse section, impart a distinctly expressed waviness to the epitheca.

Internal structure. In transverse section, well-developed radial septa of 2 orders are observed. Their total number varies from 42 (at a diameter of 6 mm) to 44 (at a diameter of 7–10 mm). The septa of the 1st order, straight or slightly curved (especially at the ends), have a thickened base in the zone of the septa of the 2nd order, while in the center they generally leave a free space, the diameter of which, probably decreasing with age, is equal to 1/5 to 1/3 of the diameter of the corallite. In one corallite (the largest of all), the septa of the 1st order reach, or almost reach, the center, leaving a free space of about 1 mm.

The septa of the 2nd order make up 0.3–0.6 of the length of the first. Their bases, as in the septa of the 1st order, are sometimes (in the young stage?) strongly thickened, and even there carinae are not indicated on the septa, or else they are in a very weak stage of development.

The tabulae at the ends of the septa of the 1st order are not horizontal, giving the structure in the center of some transverse sections a strong resemblance to that in Syringopora. In longitudinal section the characteristic form of the tabulae is clearly visible, in the form of a deep trough surrounded by an annular raised ridge. The latter is usually separated from the zone of vesicles by a depression. The distance between the tabulae is on average 0.4–0.5 mm (from 0.1 to 1 mm).

The dissepiments of transverse sections, concave toward the center and arranged in 1 (in the young stage)—2 rows, correspond to the vesicles of longitudinal sections. In this zone of vesicles stereoplasm not infrequently develops. Dimensions of the vesicles: length—0.5–2 mm, and height—0.2–0.4 mm.

The form described above differs from Schlüteria rugosa var. westsibirica in the smaller diameter of the corallites and in the character of the tabulae.

13. Schlüteria rugosa var. major nov. var.

(Table I, fig. 28).

The holotype of this species is specimen a4—a bushy colony consisting of subcylindrical curved corallites, covered with a wrinkled epitheca with growth striae. In places swellings are formed on them. In 1 cm² of transverse section there are 1–1.1 corallites. The septa on the surface of the corallite correspond to longitudinal furrows; on the flat bands between them still weaker, vanishing furrows are indicated. The change of certain properties with age is given by the following table, where \(d\) is the diameter of the corallite in mm, \(u\) is the total number of septa, \(c\) is the length of the septa of the 1st order in fractions of \(d\), \(p\) is, in the same fractions, the radius of the central area without septa, and \(n\) is the number of dissepiments between 2 adjacent septa.

\(d\)	6.5–7	\(\frac{5+8}{2}\)	8–9	9–10.5	10–12	12.5	13–14
\(u\)	42	44	46	48	50	53–54	48
\(c\)	\(1/4\)—\(1/3\)	\(1/4\)—0.28	\(1/4\)—\(3/8\)	0.3—0.4	\(1/8\)—\(1/4\)	0.3	0.35
\(p\)	0.3—0.4	0.4—0.45	0.4—0.44	0.3	?	0.4	0.27—0.28
\(n\)	1	1	1–2	2 (1 and 3 rarely)	2–3	2–4	3–5

The table given shows that the not very sharply expressed tendency for the relative length of the septa of the 1st order to increase, and the increase in the number of dissepiments, indicate the derivation of this species from more primitive forms with 1–2 rows of vesicles¹. The septa at the bases

are strongly thickened at all stages. In transverse section they are straight or slightly curved. Septa of the 2nd order almost do not emerge from the dissepiment zone. The latter are usually concave toward the center, more rarely straight; in the adult stage there appear among them incomplete and obliquely seated dissepiments, which is observed chiefly outside the zone of septa of the 2nd order. Within the limits of the latter zone, where the septa are thickened, here and there carinae are indistinctly visible (weakly developed), but in general they are absent.

In longitudinal section one may observe tabulae with edges, at the zone of vesicles, bent downward. In the center they are flat or slightly convex upward. The distance between them varies from 0.2 mm to 0.8 mm (on average 0.5 mm). At the periphery incomplete tabulae are observed, and farther on there follows vesicular tissue. The length of the vesicles varies from 0.5 mm to 1.5 mm, and the height from 0.1 mm to 0.5 mm. The base of the vesicles is inclined at an angle of 40°–90° to the axis of the corallite, i.e., some of them are arranged horizontally, and such a position of the vesicles is observed in the middle of the vesicle zone, whereas nearer the wall they in places even dip not toward the center, but toward the wall.

This variety differs from the others in its large diameter and correspondingly large number of septa, as well as in the greater development of dissepiments. In the future, by means of layer-by-layer collecting, it should be determined whether the 3 varieties of Schl. rugosa do not represent a single developmental series from var. minor to var. major.

Specimen a4 comes from the 2nd quarry above the Shcherbinskaya pit.

14. Schlüteria nalivkini n. sp.

(Pl. I, fig. 25; Pl. III, fig. 5).

External structure. There is only one fragment (a93), 21–25 mm in diameter at the upper end and 18–20 mm at the lower. The height of the fragment is about 4 cm. The surface of the coral shows constrictions. This specimen a93 has been chosen as the holotype of the species described, named in honor of Prof. Dmitrii Vasil’evich Nalivkin.

Internal structure. In transverse section of the coral there is visible a thick (1–1½ mm) wall with a concentrically layered, fibrous structure and 26 septa of the 1st order, as well as sections of curved tabulae. In addition to the septa mentioned, in places between them septa of the 2nd order are also noticeable (and in the structure of the wall they are noticeable everywhere). One of the septa of the 1st order is very short (0.6 mm); evidently this is one of the principal septa. The length of the septa of the 1st order, with the exception of the latter, ranges from 4 mm to 7 mm (and to 8?).

In the section situated several mm higher, the septa are considerably shorter, not exceeding 6 mm.

In the peripheral zone between the septa, dissepiments are observed, the true nature of which is revealed by a vertical section. In the latter, behind the thick wall, there follows a vesicle zone 1.5–2.5 mm wide. The vesicles forming it, while of slight height, attain a relatively great length of 2.5 mm and are usually inclined almost vertically. In the same zone, stereoplasm develops on the vesicles in considerable quantity.

Tabulae occupy all the remaining part of the visceral chamber, with a diameter of about 15 mm; their outer ends are bent downward, and the central area is likewise slightly deflected downward; thus, the dissepiment zone is separated by an annular depression and then by a gentle

with a ridge from the central flat-concave region of the bottom. The distance between the buds varies from 0.1 mm to 3 mm, averaging 0.5 mm.

The description given, especially the presence of a thick wall, characteristic, for example, of the genus Densiphyllum Dyb., as well as the presence of a narrow zone of dissepiments and relatively short septa, makes it possible to distinguish our species as a new species of the genus Schlüteria Wdkd., moreover forming a special group of species with a solitary corallum. However, subsequent study may show that this group has independent significance and represents the type of a new genus.

Specimen α93 was found by Prof. M. A. Usov in an outcrop situated below the cattle track of the village of Lebedyanskoye along the Maz. Kitat River, beyond the log where the Kitat slightly turns to the NW, and where the beds dip along az. 260°, at an angle of 46°.

15. Grypophyllum cylindricum n. sp.

(Table I, fig. 7).

External structure. The holotype of Grypophyllum cylindricum in the collection from the village of Lebedyanskoye is one fragment—α70—11 cm long and 30–34 mm in diameter. The surface of the corallite, which has a subcylindrical form, is covered with wrinkled epitheca. On the surface of the coral there are also visible depressions as if from adjacent corallites, which compels one to regard this coral as bushy.

Internal structure, illustrated only by a transverse section, is characterized by the presence of 34–33 septa of the 1st order. Between them, in most cases, weakly developed septa of the 2nd order are visible. Altogether, 60 septa are counted in the transverse section. The septa of the 2nd order nowhere reach the wall, being separated from it, like the septa of the 1st order, by a zone of irregular vesicular tissue without septa. However, the septa of the 1st order in places cross it and reach the wall. In places this zone without septa does not adjoin the wall directly, and then at the latter are observed the bases of septa of the 1st, and here and there also of the 2nd order, isolated from their main part. The septa are not straight-line, but weakly and irregularly curved, being arranged on the whole almost radially. Their middle part is weakly but clearly thickened. Carinae are not observed on them.

The septa of the 1st order do not reach the center, leaving in the middle an oval space 4–7 mm in diameter.

The vesicular tissue has, in general appearance, the character typical of the genus Grypophyllum.

Although this species has so far been incompletely studied, nevertheless its colonial stock, as well as the details of its internal structure, are characteristic and distinguish it from other species of the genus.

16. Cyathophyllum (?) speciosum n. sp.

External structure. This solitary coral is characterized externally by a shallow calice, surrounded by a flat rim about 7 mm wide (?). Its height is unknown, but probably about 30 mm. On the surface there is epitheca. The description was made from specimen α10—the holotype of this species.

The internal structure is characterized by two transverse thin sections. One of them, made somewhat below the bottom of the calice, gives a coral diameter of 20–21 mm. The outer zone is represented by an epitheca and a ring of stereoplasm. The latter has a concentrically undulating structure; extensions of the septa are outlined in it. The width of this ring is 1?—1½—2 mm. Next comes the visceral chamber of the coral, filled with septa, dissepiments, and tabulae. The septa are of two orders. Their total number is 56. Septa of the first order reach the center, where a tendency for them to curl counterclockwise is observed, owing to the deflection of their ends to the right (if viewed from above). One of the septa (the main one?) is longer than all the others and has an end bent like a sickle. In the peripheral zone—the zone of less dense dissepiments—the septa have normal thickness, but then the septa of both orders thicken sharply and, becoming slightly thinner, remain thick as far as the central area, 7–8 mm in diameter¹. The latter is bounded externally in part by a semicircle of stereoplasm. Before reaching this, as it were, underdeveloped inner wall, the septa of the second order and even some septa of the first order terminate. However, beyond the half-ring of stereoplasm they appear again, and where this half-ring is absent all septa enter the central area². The latter, in turn, is heterogeneous; along its periphery there are still dissepiments (relatively small and frequent) and septa of the second order (there are 44 septa there in all), while in the center (3–4 mm in diameter) there are only septa of the first order. In the peripheral zone the dissepiments are usually straight or slightly curved; in the zone of thickened septa they are strongly concave toward the center, becoming straight again nearer the center; and, finally, beyond the half-ring they are concave, locally incomplete, and in general less regular. A radius intersects from 10 to 19–20 dissepiments between the septa. In the zone of thickened septa the dissepiments give them the appearance of a serrated spear or harpoon. Carinae, if these serrations are not counted as such, are absent.

The second section, with a diameter of 13.5–14 mm, is less complex. The peripheral zone of stereoplasm is also present here, and the nature of this zone is visible: in places, instead of stereoplasm, a vesicular tissue is seen, through which the septa do not pass (at least some of them). Zones of thickened septa are not observed here, and all the relatively thick septa become slightly thinner toward the center. The central area, without dissepiments, through which only septa of the first order pass, showing a tendency toward coiling, has a diameter of about 4 mm. The total number of septa is also 56. The dissepiments are usually concave toward the center. A radius intersects from 5 to 16 dissepiments. Carinae are absent.

The species described is apparently new, with an original internal structure. The latter by no means coincides with, and differs sharply from, that of Cyathophyllum. And if it is assigned to this genus, it is only because it cannot in general be included in any of the known genera. Most likely, the present species represents a new group of species, but to distinguish it under a new generic name is still premature because of the insufficient study of the material.

The holotype of this species—no. 10—comes from the banks of the Maz. Kitag above Shcherbinovka.

17. Neospongophyllum sp.

(Plate IV, fig. 3).

External structure. This species is represented by only a single fragment (a 85) of small length (about 35 mm), from which 2 sections were made. The surface of the corallite has not been preserved. The diameter of the corallite is 20–21 mm. Here and there, preserved traces of the epitheca show longitudinal striae—possible traces of rudimentary septa on the wall.

Internal structure is extremely distinctive. In transverse section, 3 zones are clearly distinguished: 1) a central zone of solid septa with a diameter of about 9–10 mm; 2) a zone of discontinuous septa, separating the first from 3) an outer zone of large, rather irregular vesicles 3–4 mm wide at a diameter of 21 mm. In the latter, a radius crosses 2–4 vesicles; their length varies from 1–1.5 mm to 5 mm and even to 7 mm, and their height—from 0.1 mm to 3 mm. The vesicular zone is filled to a considerable extent with sclerenchyma.

In the intermediate zone, besides the septa of the 1st order, discontinuous ones are also observed, though rarely, almost between every pair of septa of the 1st order, usually in the form of spines—the septa of the 2nd order. The total number of septa here is 93.

In the central zone only dissepiments and curved septa of the 1st order are visible; by their arrangement they reflect the bilateral symmetry of the coral and reach the center. The number of septa here is 49. Carinae are absent. The number of dissepiments between a pair of septa is 9–12.

The absence of a longitudinal section does not allow completion of the study of this species or comparison of it with those described earlier. The described specimen was found on the Alchedat River, where at the end of the village of Lebedyanskoye it turns sharply to the east.

18. Dialithophyllum asiaticum n. sp.

(Plate I, figs. 19, 20).

External structure. This species is represented by incomplete fragments of solitary corals of conical, curved form. One of them—a 26 a—has been chosen as the holotype. The height of the coral was more than 25 mm. The diameter of the transverse section in the upper part of the coral is 21–23 mm (18 mm in a 26—young stage).

Internal structure is extremely distinctive. In transverse section, 3 zones are clearly distinguished: 1) a central area 6–8 mm in diameter (5–9 mm in a 26 and 7–9.5 mm in a 26 a), devoid of septa and filled with comparatively large vesicles up to 3 mm long and up to 1.3 mm high; 2) it is then surrounded by a middle zone, where there are both vesicles (not more than 2 mm long) and thick (0.15–0.5 mm), curved septa, numbering 37¹), between which often incomplete dissepiments are situated (and rarely even resting entirely on one septum); 3) finally, between the 2nd zone and the wall there is situated a peripheral vesicular zone 1–2½ mm wide; this zone is not crossed by septa at all, or only by isolated ones. In places on the wall in this zone sit rudimentary

¹) At a diameter of 14–15 mm their number is 34, and at a diameter of 18–22 mm (in a 26 and in a 26 a) this number is 36.

septa, and the length of the vesicles in it reaches a maximum of 2.5–3.5 mm, while the height is 1.5 mm. In the second zone, whose outer diameter is 16–17 mm, the septa are interrupted in places (closer to the center), and then beyond the zone of vesicles they appear again in rudimentary form (as if in the form of spines). The radius crosses 5–11 dissepiments between adjacent septa (6–8 in specimen a 26 and 7–10 in a 26a), and in all along the radius there are from 16 to 22 vesicles (from 10 to 13 in a 26).

In specimen a 26 (young stage) the bilateral arrangement of the septa is perceptible, and a fossula is indicated by four short septa; to this fossula, at the second end of the diameter, corresponds another, marked by 3 short septa. Two septa among all the others (the sixth in count from the first fossula) are the longest, the distance between their ends being 1.5–2 mm.

The dissepiments are usually convex toward the center or straight; concave ones are almost absent. Incomplete vesicles are often observed (especially in a 26a), resting with one end on vesicles and not on septa.

On the sides of the septa, low tubercles are observed in places—a peculiar expression of weakly developed carinae. The latter, however, are better perceived in longitudinal section of the septa, in the structure of the substance composing them.

The longitudinal section (a 26 and a 26a), in agreement with the transverse section, also reveals three zones: the central and peripheral zones consist of gently inclined or horizontal vesicles, while the intermediate zone consists of steeply inclined and even vertical ones. The dimensions of the vesicles in mm are given in the following table.

	Length of vesicles	Length of vesicles	Length of vesicles	Height of vesicles	Height of vesicles	Height of vesicles
	Min.	Max.	Mean	Min.	Max.	Mean
Peripheral zone	0.3	3.6	1.5–1	0.1	1.1	0.3–0.5
Central zone	0.3	3.3	1.5–2	0.1	1	0.3–0.4
Intermediate zone	0.3	4.0	1–1.5	0.05	0.5	0.15–0.3

In one of the longitudinal sections it is evident that in the peripheral zone, into which the ends of the septa still enter, outside these septa on the vesicles there are occasionally visible ridges—rudimentary dentate septa or fused spines, situated in the radial plane. If these septa are directed upward by the denticles and are elongated horizontally, then analogous rudimentary narrow septa in the central region are elongated vertically, and no dentation is noticed on them.

According to the conclusions of Wedekind, who studied the genus Dialithophyllum, the latter is characteristic of the Givetian stage D₂.

The available specimens were found along the Alchedat River above the village of Lebedyanskoye.

19. Cystiphyllum senecaënse (?) Bill.

(Table I, figs. 17, 18).

1. Cystiphyllum senecaënse. 2, p. 139.

The dimensions and form of the colonies of this bushy¹ coral are unknown, since we have only fragments of corallites. But judging by the dimensions of the latter, the colonies must have been large; in diameter

¹ This was established in the summer of 1929, when corallites connected into colonies were found.

corallites, equal to 35--37 mm, this species is sharply distinguished from the other Lebedyansk forms; moreover, the length of the fragments reaches a considerable size.

Individual corallites have a subcylindrical form, with the usual growth striae and wrinkles on the epitheca.

The connection of the corallites with one another occurred, it seems, only at their bases.

The internal structure of the corallites is characterized by the complete development, inside a thin outer wall, of vesicular tissue, to which spines are also attached.

The vesicular tissue consists of vesicles of various sizes forming zones. Thus, for example, in the available transverse thin section there is observed a zone of small vesicles 15--23 mm in diameter, enclosed within larger vesicles. Whereas in this zone the maximum length of the vesicles is 2.5--3 mm, in the remaining area of the section one may find vesicles 5--6 mm long. The height of the vesicles ranges from 0--0.1 mm (in the small or flat ones) to 1 mm in the mentioned zone and up to 3 mm in the zone of large vesicles. The number of vesicles over the entire transverse section is approximately 400.

The spines are weakly developed on the wall and very conspicuous on the vesicles. In one sector of the transverse section they, being arranged radially, even created a semblance of discontinuous septa.

From the Corniferous limestone of Canada ($D_2^1$), Billings described, under the name C. Senecaënse, a species close to ours in the magnitude of the diameter of the corallites. However, this species, it seems, is not colonial, which is not entirely clear. True, Billings gives the description as though the coral were solitary, but the enormous length of the corallites of his species makes one think that he is dealing with colonial forms. This uncertainty, as well as the impossibility of making a comparison of the internal structure, compels one to assign the Lebedyansk form to Billings’s species conditionally. It is quite possible that it represents a new species.

As the plesiotype of Cystiphyllum senecaënse (?) Bill. serves specimen a 72, delivered by Prof. M. A. Usov from outcrop 235 (situated above M. Koshelka). I found bushy stems of this coral in the limestones of the main quarry of the village of Lebedyanskoye (Fig. 1, stone quarry).

20. Cystiphyllum macrocystosum n. sp.

(Plate III, fig. 6)

External structure. As the holotype of this species, specimen a 90 was selected--a separate fragment of a coral, 18--19 mm in diameter and 25 mm long. The form of the coral is subcylindrical. The usual constrictions, wrinkles, and growth striae are present.

In internal structure this species is characterized by very large vesicles (larger at the periphery) and their analogues, and by a not infrequent deviation of the form of the vesicles from their normal appearance. Their length varies from 1 to 7 mm, and their height from 0 to 2 mm. The large size of the vesicles is also reflected in the fact that, with a transverse-section diameter of 18--19 mm, only about 78 of them are counted. Spines are not noticeable either on the wall or on the vesicles, and only in places, on the wall, are flat tubercles or projections visible--a weak expression of septa.

Species close in character of the transverse section are not known to me. Specimen a 90, found in the vicinity of the village of Lebedyanskoye, has no precise indication of its locality.

TABULATA.

21. Favosites helderbergiae Hall var. mesodevonica n. var.

External structure. This species is represented in the present collection by two fragments (a 76—a 77) of a massive stock, the height of which was not less than 12 cm, and the diameter, probably, considerably more than 20 cm. By the character of the transverse section this species belongs to the group of Favosites gothlandicus Lam. with more or less equidimensional corallites. The number of the latter per 1 cm² of transverse fracture is approximately 55.

The diagonal of the corallites is on average 1.7 mm; in young corallites it assumes ever smaller values, beginning from zero, and in the largest reaches 2 mm.

Internal structure. The corallites within the colony are parallel and rectilinear. Pores are situated only on the walls and usually in 1, more rarely in 2—3 rows. The distance between pores is 0.9—1 mm on average, varying from 0.7 to 1.7 mm (such a maximum was observed on a wall with three rows of pores). In the case of two-row pores this distance is 0.8—1.3 mm (with a wall width of 1 mm). The pores alternate in the rows.

Tabulae in their form represent an indistinctly expressed type of F. alveolaris, which is manifested both in the transverse fracture and in sections coinciding with the walls. Since this character is indistinctly expressed,¹ the number of pits on the tabula is not determined. The tabulae in section are for the most part horizontal, straight, which is disturbed where the section crosses a depression on the tabula. The distance between tabulae is on average 0.75 mm, varying within the limits from 0.2 mm to 1.3 mm. Spines on the walls, beautifully prepared by weathering, are completely imperceptible. Squamulae are absent.

Comparison with related forms. In the characters described above, our specimen stands closest of all to F. helderbergiae Hall, the only Devonian species devoid of squamae and at the same time distinguished by pits on the tabulae. But this species of Hall’s differs by the presence of clearly expressed longitudinal striae (longitudinal rows of spines?), and also by generally smaller corallite dimensions.

The holotype of the variety described is specimen a 77, which was supplied by Prof. M. A. Usov from the Alchedat River and evidently comes from the horizon immediately overlying the massive limestones of the quarry above the mouth of the Kamenushka River.

22. Emmonsia (Favosites) hamiltoniae Hall.

(Pl. II, figs. 4, 5).

1. Favosites hamiltoniae, 7, pl. XXXIV, fig. 4.

This species is represented by one specimen—an almost complete stock. The height of the colony is equal to or slightly more than 65 mm, and the diameter—not less—

¹ At the edges of the walls the tabulae are only wavy, without funnel-shaped depressions.

at least 110 mm. In the character of the transverse section of the colony, this species belongs to the group F. gothlandicus Lam., the diagonal of the corallites usually being 1.7 mm, ranging from 0.5 mm to 2 mm. In 1 cm² of transverse section about 55 corallites are counted, and 8 corallites are crossed by a line of 1 cm.

The internal structure is characterized by the following features. Pores, situated only on the walls, form one or two vertical rows; two rows are observed when the wall is 1–1.2 mm wide, and one when the width is 0.9 mm or less. The distance between pores is 0.8 mm (according to individual measurements); the diameter of the pores is about 0.2 mm.

Tabulae are complete, straight or slightly curved, horizontal or inclined. There are no pits on the tabulae. In rare cases incomplete tabulae are observed, i.e. those resting upon underlying tabulae. The distance between individual tabulae varies from 0.1 mm to 1.2 mm; on average it is 0.5 mm.

Walls are comparatively thin; their thickness is usually about 0.1–0.2 mm (for the double wall). Thickening of the walls is not noticeable, at least in the preserved part of the coral.

Squamae are developed extremely strongly, which is characteristic of this species. They are usually thin and narrow, but long; at least in places they reach the center of the corallites. The squamae form discontinuous vertical rows—2–3 rows on each wall; the vertical distance between squamae is often 0.25, and sometimes 0.3–0.4 mm.

In addition to squamae, there apparently are also spines with isometric bases.

As is evident from the description given above, this species belongs to the large group of species of Favosites, to which—among others—Emmonsia hemisphaerica Edw. et Haime also belongs. This group is characterized by the presence of squamae. It is also characterized by a special geological distribution. Its presence in the Silurian is highly doubtful. In the Devonian, however, especially in the Middle Devonian, it becomes widely developed. It is interesting to note that apparently only representatives of this group pass into the Carboniferous. Therefore, it seems to me that it would be very advisable to distinguish this group under the name Emmonsia Edw. et Haime.

Among all the forms belonging here, the Lebedyanskoye species is closest of all to F. hamiltoniae Hall, for example to the form figured by Hall in fig. 4, pl. XXXIV (Illustr. Dev. Fossils). Although Hall here figured, and Rominger described (under the name F. hamiltonensis), different species, since they have not yet been described and studied in detail by anyone, and since among them there apparently are forms identical with the Lebedyanskoye form, the latter may be referred to F. hamiltoniae Hall; at the same time, provisionally, until a more detailed study of this American group of species, it is advisable to regard the described Lebedyanskoye form as a Siberian plesiotype of F. hamiltoniae Hall, represented—specifically—by specimen α 78.

Also close to the form described is F. hemisphaericus Iand. et Shum., but it differs essentially by an even greater development of squamae.

F. hamiltoniae Hall is widely developed in North America in the Hamilton formation.

Locality of the plesiotype is not precisely known (“near the village of Lebedyanskoye”); however, it almost certainly comes from the same horizon as specimen α 77.

Group Emmonsia (Favosites) sibirica.

23. Emmonsia (Favosites) sibirica, n. sp.

(Plate II, figs. 1, 2; Plate III, fig. 17.)

This species is represented by a single specimen (a 78), which has also been chosen as the holotype.

The external structure of this coral is characterized by a conical, or more precisely pear-shaped, form with a broad base, the height of the stock being approximately 70 mm and the diameter 60 mm. On the surface the coral somewhat resembles representatives of Heliolites with a weakly developed coenenchyme. This impression is produced because the species under consideration, in the arrangement of its small and adult corallites, belongs to the group of F. Forbesi. This impression is further strengthened by the fact that the transverse section of the corallite cavity is sometimes round, sometimes rounded-polygonal, owing to deposition of stereoplasm to one degree or another. The diameter of the cups varies from 0.1 mm to 1.25 mm, usually equaling 1 mm (in adult corallites); the diagonal of the corallites is usually 1.5 mm, reaching 1.8 mm. In 1 cm² of transverse section there are 110–120¹ corallites, which corresponds to an average diagonal of 1.15–1.25 mm for equal corallites; in the same section, a line 1 cm long crosses 10 corallites.

The internal structure first of all shows that the conical form of the coral is clearly observed even in the early stage of its growth, beginning with a diameter of 2 cm, as is distinctly visible owing to the annually (?) differently colored growth surfaces. It should further be noted that the diagonal of the corallites in the early stage of coral growth remains of the same size as in the adult stage. Likewise preserved in the early stages is the characteristic feature of the species consisting in the walls being strongly thickened by deposition of stereoplasm. This is a very interesting fact, for in general deposition of stereoplasm on the walls was considered characteristic only of branching forms assigned to the genus Pachypora; moreover, such thickening was observed only in the peripheral part of the branches of Pachypora.

The pores in the species described are situated on the walls of the corallites, where they form a single vertical row², not always, however, situated along the middle of the wall. The distance between pores varies from 0.5 mm to 1.2 mm (usually 0.9–1 mm). The pores are sometimes round, sometimes oval in form; their diameter is 0.2 mm, and the long diameter of the oval pores is up to 0.35 mm.

The tabulae, as is characteristic of the genus Emmonsia, are often incomplete, i.e., supported partly not by the wall but by the underlying tabula. The tabulae are sometimes straight, sometimes more often curved, sometimes horizontal, sometimes inclined; among the curved ones, those concave upward are very common, and also not infrequently those with a sinusoidal bend either upward or, more often, downward. The distance between tabulae varies from 0.1 mm to 0.8 mm; on average it is 0.4–0.5 mm.

The walls in Em. (F.) sibirica, as already stated, are strongly thickened both in the adult and in the early stage. However, in one place of the transverse thin section, where the dark walls of the corallites become light, they are weakly or not at all thickened³; there the section of the corallites (and in

in adults as well as in juveniles) becomes polygonal, and the thickness of the double walls is 0.08–0.25 mm, whereas usually, owing to the deposition of stereoplasm, this thickness is 0.2–0.3 mm, varying within 0.15–0.5 mm. In places a concentric structure is clearly noticeable inside the walls, marking separate stages in the deposition of stereoplasm.

Squamae are well expressed and are represented by thin (0.05 mm), comparatively narrow (0.1–0.2 mm) plates, extending rather far toward the center; sometimes they reach the center. In longitudinal section of the corallite they give longitudinal sections with the end curved arcuately upward.

Squamae in places form indistinct vertical rows (1 or 2) on the wall, with a distance between individual squamae of about 0.25 mm.

Spines. In addition to squamae, spines are also observed on the walls of the corallites. At least in sections almost coinciding with the wall, isometric sections of their bases, 0.1 mm in diameter, are observed. In places it can be established that these spines are arranged in one row at a distance of 0.5–0.6 mm.

The depth of the calice, according to the vertical section, lies within 0.7–1.5 mm.

Em. (F.) sibirica, by its internal characters, belongs to the genus Emmonsia Edw. et Haime, or to the large division of favositids with squamae. At the same time, however, it may be considered the first in a special group of species characterized by thickened walls.¹ Since the latter character is inherent in Em. (F.) sibirica even at an early stage of coral growth, I consider it a distinct species not yet described by anyone. In fact, among species having squamae and a massive corallum, rounded-polygonal calices are possessed, according to Rominger, by: F. billingsii Rom., F. nitellus Winch., F. placentus Rom., F. radiatus Rom. and F. winchelli Rom. However, analysis by other authors shows that, at least in some of these species, this character is acquired not through thickening of the walls by stereoplasm, but because the large corallites have many sides, being surrounded by small ones. Thus, with respect to F. radiatus Quenstedt (17, 57) it is definitely stated that its walls are thin. Further, for the species F. hamiltonensis Rom., F. basalticus Goldf., F. explanatus Hall and F. tuberosus Rom., thick walls are noted in rounded-polygonal section; however, in some cases the roundness here is caused by the circumstance mentioned above, and nowhere is the deposition of stereoplasm definitely noted as the cause of this roundness; even if its presence is admitted, all the species mentioned differ from the species described by a number of characters, in particular by the larger size of the corallites and by the form of the colony.

Specimen α 79, supplied by Prof. M. A. Usov and found by him in the channel, probably comes from the same horizon as the preceding two species.

24. Pachypora cervicornis (?) de Blainv.

(Table II, fig. 22; table III, figs. 14, 15).

1. Favosites cervicornis. З. p. 243.
2. Pachypora cervicornis, de Blainville, sp. 12, p. 82, pl. IV, figs. 3–3 d.

External structure. The plesiotype of this species in the collection studied is specimen a 54. It is a fragment of a cylindrical branch of a bushy colony; the diameter of the branch is 20–21 mm. Almost equal-sized corallites emerge on its surface; their diagonal varies from 1.6 mm to 2.5 mm (rarely to 2.7 mm). There are 28–29 of them per 1 cm², and a line of 1 cm intersects about 5–6 corallites.

Internal structure is typical of Pachypora. The corallites, curving gently, approach the surface at an angle of 70°–90°. The pores are single-rowed, 0.2–4.5 mm in diameter; the distance between them along the corallite is 1–1.2 mm. The tabulae are numerous—sometimes straight and transverse, sometimes curved (often concave upward), sometimes incomplete and strongly inclined. Some even run parallel to the wall for a certain distance. The distance between tabulae varies from 0.1 mm to 1.5 mm; on average it is 0.5 mm.

The long (0.3–0.4 mm) spines have a large (0.1–0.25 mm), round transverse section; they are arranged either irregularly or in vertical rows, with the distance between neighboring spines of a row being 0.35–0.5 mm. In addition to spines, there are squamae, which are especially clearly visible in transverse sections of the corallites as rectangular patches.

The corallites also have a rounded section of the visceral chamber in the center, owing to the thickening of the walls, whose thickness increases from 0.15 mm to 1.2 mm at the periphery. The concentric and radial microstructure of the sclerenchymal deposits is clearly visible. Multiplication of corallites takes place by intracalycinal division (?) and lateral budding.

The species described fully agrees with the diagnosis given for this species by Edwards and Haime. However, the later study of this species by Nicholson shows the absence of squamae in it. Thus, if P. cervicornis is accepted as described by Nicholson, then the Lebedyanskoye form described above will have to be separated and referred to the widely distributed group of species with squamae.

The exact position of the plesiotype in the vicinity of the village of Lebedyanskoye is unknown.

25. Pachypora cervicornis var. major n. var.

(Pl. III, fig. 4).

External structure. The holotype of this variety (a 55) in the collection described is represented by a fragment of a branch overgrown with an actinostroma (?). The diameter of the branch is 25–28 mm. The corallites, almost identical on the surface, have there a diameter of no more than 2.5–2.7 mm and usually not less than 1.7 mm; there are 24–30 of them per 1 cm², and 4–5 along 1 cm of the circumference.

Internal structure is rather peculiar. In the center of the branch there are about 35–40 corallites running parallel to the axis of the branch and occupying a central area with a diameter of about 5–6 mm. In the central area, as on the periphery, there are also corallites with a diagonal of 2 mm, but usually they are smaller. The pores, with a diameter of 0.25–0.35 mm, are round, single-rowed, although not everywhere located in the middle of the wall. The distance between them along the wall is 1.2–1.5, rarely 2 mm. In addition to the normal short pores, perpendicular to the wall, in the central as well as in the peripher—

of the region, pores or sinuous pore canals are observed, situated in place of the ribs of the corallites parallel to them and partitioned off by transverse dissepiments. Their diameter is also equal to 0.25 mm.

The thickness of the paired walls, even in the central zone strongly thickened by the deposition of structural sclerenchyma, is at minimum 0.05 mm (and up to 0.15 mm). With the smooth bending of the corallites toward the periphery this thickness increases rather gradually, reaching 1 mm at the surface of the branch. Here the microstructure of the walls is clearly visible, already illustrated more than once, for example by Nicholson (12, Pl. IV), with microscopic growth surfaces and with fibrous aggregates of calcite perpendicular to them.

The tabulae have certain peculiarities in this species; namely, they are often incomplete, and some of them do not even rest on the lower-lying neighboring ones, but sit wholly on one wall, i.e. in essence they have an arrangement characteristic of vesicular tissue. Alongside these there are also normal (complete) tabulae—sometimes straight, sometimes curved, sometimes transverse, sometimes obliquely placed. The distance between the tabulae varies from 0.1 mm to 3 and even to 5 mm. On average it is 0.5–1 mm.

Spines with a round transverse section are very strongly developed; they form—though not everywhere—vertical rows, with a distance between neighboring spines of 0.5 mm (0.25–0.6 mm). The diameter of the base of the spines reaches 0.35 mm, and their length is 0.3–0.5 mm. Some spines have completely blunt ends, representing not a cone but a cylinder.

The presence of sinuous internal pores—a characteristic feature of Michelinia according to Nicholson—as well as the similarity of the tabulae to vesicles, noticeable there and here, brings this typical species of Pachypora closer to Michelinia.

Of the species described earlier, the closest to ours is Pachypora cervicornis (de Blainv.), to which the form just described, often encountered in the Devonian near the village of Lebedyanskoye, should be assigned. However, the branch diameter, larger than usual, the special character of the tabulae, the large blunt spines, and the special pore canals along the ribs of the corallites distinguish it from typical P. cervicornis, as represented in Nicholson’s description.

The locality in the area of the village of Lebedyanskoye from which the form described above comes is unknown.

26. Pachypora dubia Edw. et Haime

1. Favosites dubia. 3, p. 243.

External structure. This species, together with its plesiotype—а23—forms branching colonies, represented in the collection only by fragments of branches 8–20 mm long and 5–7 mm in diameter. This diameter, at branching, reaches 10 mm. The diagonal of the more or less uniform corallites varies within the limits from 0.8 mm to 1.5 mm, rarely reaching 1.9 mm. On 1 cm² of the branch surface there are 60–80 cells. As is visible in section, the corallites, bending smoothly, approach the surface of the branch at an angle of 40–60°. Owing to this the calices are also arranged not perpendicularly to the surface, and the lower edges of the calices overhang the upper ones; for the same reason, when the branch is viewed at a right angle to its axis, the sections of the calices

appear elliptical, although in reality their transverse section is circular, with a diameter of 0.5–0.7 mm. This oblique position of the cups and the corresponding character of the external appearance distinguish the present species of pachyporids from the village of Lebedyanskoye from others. The striae and denticles along the margins of the cups—a characteristic feature of the genus Striatopora—are not observed here.

Internal structure. The pores pierce the walls perpendicularly. There are no sinuous pore canals parallel to the axis of the corallites. The diameter of the round pores is 0.1–0.15 mm. The distance between them is 0.45–1.15 mm (measured in only two places). In addition to these small pores, there are also somewhat larger pores—0.15–0.3 mm in width and even up to 0.8 mm. Their outline is less regular. These are rather entire “windows” in the walls than ordinary pores. The tabulae are comparatively rare, straight or concave upward. The distance between them, where several occur in one corallite, is 0.5–1 mm. Sometimes these tabulae are incomplete; at other times, bending strongly, they even run parallel to the wall. However, they cannot be properly studied because of the indistinctness of the section. Spines, apparently, are present, since in longitudinal section short (0.9 mm) blunt spines with a broad (0.17 mm) base are visible on the walls, and in some places there are also their round transverse sections. But at the same time there are also squamatae, for in one of the corallites their transverse sections are visible at a distance of about 0.15 mm from one another, elongated across the corallites; the length of these sections is 0.15–0.17 mm, and the width 0.05–0.08 mm. The same squamatae also fell into one of the transverse sections of the corallites, the internal section of the visceral chamber acquiring a bay-like outline from six squamatae situated in it. The thickness of the walls varies from 0.1 mm in young corallites of the center to 0.5 mm in adults at the periphery.

Among pachyporids, the following are known which, by the diameter (D) of the branches, closely approach the Lebedyanskoye form: P. dilacerata Pocta (D = 3–5 mm), P. dubia Edw. et H. (D = 10–12 mm), P. meridionalis Nich. et Eth. (D = 6–7 mm), P. pittmani Eth. (D = 10 mm), P. ramosa Pocta (D = 5–8 mm), P. reticulata Gürich (D = 8 mm), P. cervicornis according to Bogatyrev (D = 7–9 mm), P. lonsdalei (Roem.) (D = 5–7 mm), P. reticulata var. intermedia Gürich (D = 8–10 mm), and the form from S₂ of Indo-China, described under the name Favosites cf. dubia Edw. et Haime (D = 5–6 mm). Species having a diameter greater than 7 mm differ strongly from the Lebedyanskoye form in the size of the diameter, with the exception of Pachypora dubia (Blainv.) Edw. et H.; and of the remaining ones, in this respect only P. ramosa Pocta from D₁ of Bohemia is identical. In addition, P. dilacerata Pocta differs in the elliptical and smaller section of the branches, P. meridionalis in the peculiar worm-like canals connecting the cups on the surface of the branch, and P. lonsdalei (Roemer) in the inequality of the cells. The Indo-Chinese form (F. cf. dubia) from S₂ has not been studied with respect to its internal structure, and therefore comparison is impossible.

In view of the fact that the presence of squamatae and spines in the Lebedyanskoye form, not recorded for Pachypora dubia (Blainv.) Edw. et Haime, as well as its smaller diameter, may prove not to be characteristic of the described species of pachyporids, it is better for the time being not to separate it from P. dubia, considering the specimen represented by no. a23 as a plesiotype until a more complete comparison and study.

As for P. ramosa Pocta, it differs from the Lebedyanskoye form in its shape (weaker development of branches, partly club-

visible colonies), a serrated rim of the calices, a smaller diameter of the corallites, and rarer tabulae.

The plesiotype $\alpha 23$ comes from the area of the village of Lebedyanskoye; its exact position is unknown.

27. Pachypora dubia var. minima n. var.

External structure. In the collection studied there are several small silicified fragments assigned to the preceding species, but differing somewhat in size. Their study is made difficult by the fact that it is very hard to prepare two thin sections from a single fragment. These fragments of branches have a diameter of 4–5 mm, and their length was not less than 15 mm. The branches diverge in dichotomous branching at an angle of about 70°. The diameter of the corallites is 0.75–1.5 mm, usually 1.2 mm; there are about 88–100 cells per 1 cm² of surface. The grouping of calices into rows is clearly expressed, but not along the generatrix of the cylindrical branch, rather along a steeply descending spiral. The internal diameter of the perfectly round calices is 0.5 mm, varying only very slightly from 0.4 mm to 0.6 mm.

Internal structure has been studied incompletely, from a single transverse section, in the area of which about 40 corallites are counted. The diagonal of the corallites varies from 0.35 mm in the center to 1.2 mm at the periphery, and the thickness of the walls from 0.15 mm to 0.5–0.6 mm. Some cells, even in the center, are entirely filled with stereoplasm. Spines on the walls seem to be absent.

Pores are present and, probably, are arranged in one row on the walls. Tabulae are straight, transverse. The holotype is specimen $\alpha 32$, originating from the area of the village of Lebedyanskoye.

28. Pachypora alveolitiformis n. sp.

(Plate II, figs. 6, 7).

External structure. Colonies of this species consist of branches with a diameter of 24–30 mm. The height of the structures is unknown, since only fragments no more than 40 mm long are available. On the surface of the fragments one may observe, characteristic for Pachypora, corallite calices surrounded by thick walls, with a diameter of 0.15–0.25 mm. Owing to the strong thickening of the walls, they are not densely arranged.

Internal structure. Transverse and longitudinal sections of the branch show that only a relatively small (about 5 mm in diameter) central region of the colony is occupied by comparatively thin-walled corallites running parallel to, or at a very acute angle to, its axis. It is true that here, too, there is an uneven deposition of stereoplasm, as a result of which the section of the corallites is rounded-polygonal (with a double-wall thickness of 0.05–0.15 mm). But outside this central zone the corallites turn rather sharply, and their walls become extremely strongly thickened, reaching 0.7 mm, if not more. Toward the outer surface the corallites approach almost perpendicularly (at an angle of about 80–85°).

In all sections, pores of round or elliptical section are clearly observed, more precisely pore canals with a diameter of 0.15–0.2 (rarely 0.25) mm. These canals usually have a minimal diameter in the middle of the walls, increasing considerably.

to the corallite cells. The pores are arranged in vertical rows, one on each wall, and the distance between neighboring pores of a row is 0.9 mm, varying within the limits of 0.8–1 mm. In the zone of strongly thickened walls, the pores show a clear tendency to lie at nearly the same level in neighboring corallites.

It is interesting that in places the pores do not run perpendicular to the walls, but, bending, deviate strongly to the side. In the pore canals, within the walls, the same transverse partitions (tabulae) are observed as in the corallites themselves; moreover, the internal diameter of the latter is almost equal to the diameter of the pore canals, sometimes reaching 0.3 mm; only in the center of the colony does this value reach 0.5 mm.

The tabulae are fairly well developed; they are now straight, now convex or concave, now “horizontal,” now slightly inclined. The distance between them in the central zone, where they are rare, is large: not less than 1 mm; sometimes over 5 mm not a single tabula is visible; in the remaining part this distance is equal to 0.5–0.6 mm (from 0.2 mm to 1 mm).

Squamae are absent, while the spines are very clearly visible; their diameter is often equal to 0.05 mm, and their length does not exceed 0.1 mm; in sections almost coinciding with the inner surface of the wall, the spinules do not show a regular arrangement and appear scattered in large numbers over the surface of the wall. However, this has not been established exactly, since in such sections the spinules are not distinct.

The thickness of the corallite walls varies greatly. In the outer zone, owing to the expansion of the pore canals at their mouths, the walls in longitudinal section often acquire a wavy or reticulate outline. Where the pigmentation of the walls by organic matter is more strongly developed, traces of accretion within the walls are visible, proving that the edges of the cups were sometimes sharp and sometimes comparatively rounded. Here and there the microstructure of the wall substance is visible; it reflects the arrangement, in concentric layers, of carbonate individuals situated perpendicular or almost perpendicular to the wall. In other places of the coral the walls appear to consist of structureless stereoplasm¹.

The holotype of this species is specimen α49, found in the vicinity of the village of Lebedyanskoye.

29. Alveolites suborbicularis Lam.

1. Alveolites suborbicularis M. Edwards and Haime. Brit. foss corals, p. 219, pl. 49, fig. 1.

2. Alveolites suborbicularis Nicholson. 15, p. 126, pl. VI, f. 2.

In the Lebedyan Devonian, as well as along the Alchedat and near Shcherbinovka, Alveolites suborbicularis Lam. is very widespread. There it occurs in the form of massive colonies, reaching more than 6 cm in height and more than 12 cm in the horizontal direction. In 10 mm of transverse section, 20 cells are counted. A detailed study of the internal structure by means of thin sections has not been carried out. In this connection it should be said that such an investigation of all the available material would probably have shown the heterogeneity of the group Alveolites suborbicularis and would have made it possible to distinguish several varieties or even species.

In conclusion it should be noted that the wide distribution, and even the conspicuous rock-forming significance, of massive Alveolites is characteristic of the upper part of D₂ not only from the village of Lebedyanskoye, but also from the western margin of the Kuznetsk Basin, as well as from the southwestern margin of the Salair. In the area of the village of Lebedyanskoye Alveolites suborbicularis was found both along the Alchedat and in the 2nd quarry of Shcherbinovka.

30. Alveolites arbusculus n. sp.

(Table II, figs. 19, 20).

External structure. One of the common representatives of the fauna of the village of Lebedyanskoye is a species of the genus Alveolites forming thickly branching forms. The diameter of these branches is usually 30 mm (from 25 to 45 mm), and the length of the available fragments exceeds 95 mm; of course, the height of the corallum was several times greater. On its surface are observed corallite calices characteristic of Alveolites, with a diameter of 0.5–0.8 mm.

Per 1 cm² there are about 400 of them; and a line 1 cm long intersects about 18–20 corallites along the axis of the branch and 12–18 across it.

Internal structure, revealed by transverse and longitudinal sections of the branch, is characterized above all by the arrangement typical of Alveolites of corallites, which approach the surface of the branch obliquely, usually at an angle of about 30–40°, both in transverse and in longitudinal section. In places this angle reaches 80°. It is interesting to note that in one place in a longitudinal section of the branch the corallites, bending, are directed even downward, and in transverse section their bends outline a plane of bilateral symmetry. The diameters of the corallites in the central part of the branch remain approximately the same as on the surface: 0.5–0.6 mm (rarely 0.7 mm); this is confirmed by the fact that a horizontal line 1 cm long there likewise intersects about 20 corallites, and that in 1 cm² there are 475–500 corallites. Thus, with the growth of the coral, the diameter of the corallites does not change appreciably.

Since in the center of the branch the corallites are cut by a transverse section of the branch likewise transversely, we have the opportunity to verify that there too the corallites have the section characteristic of Alveolites.

The pores in this species are round or oval. The diameter of the pores is 0.15–0.25 mm. The pores are situated on the walls, forming only one row. The distance between pores is approximately 0.7 mm (from 0.6 to 0.85 mm).

The tabulae are developed uniformly in all parts of the colony; they are sometimes straight, but more often curved, and they are usually concave upward and outward and comparatively rarely convex. In relation to the axis of the corallites they are arranged sometimes transversely, sometimes somewhat obliquely. In some places incomplete tabulae are visible, i.e., tabulae resting partly on the underlying tabula. The distance between tabulae, varying from 0.1 mm to 1.5 mm, averages 0.4–0.6 mm.

Squamae are absent. On the other hand, blunt, small, short (0.05–0.08 mm), but numerous spines are well developed. They often form vertical rows, with the distance between spines of a single row being 0.1–0.2 mm. Such rows, judging from transverse sections of the corallites, may be counted as about 12, which agrees approximately with the distance between them (about 0.1 mm).

The walls of the corallites in the species described—a typical species of Alveolites—are nevertheless somewhat thickened. Even in the center of the branch, where

the wall thickness is 0.05–0.15 mm; this thickening is expressed in the rounded cross-section of the visceral chamber, and in the rounding of its angles when the wall thickness is uneven. On the surface of the branch, however, this wall thickness reaches 0.2–0.3 mm and even a little more. It is true that the concentric and fibrous structure of the stereoplasm deposits is not noticeable here, but this is probably the result of relatively poor preservation.

The holotype of this species is specimen a 50, the precise locality of which in the region of the village of Lebedyanskoye is unknown.

Natalophyllum nov. gen.

Diagnosis of the genus. The corals of the genus Natalophyllum form, so far as is known, branching and lamellar colonies. The appearance of the outer surface of the branches is extremely characteristic: it partly resembles the surface of colonies of Alveolites, and partly the tangential section of certain stromatoporoids. The internal structure is characterized by dimorphism. The central part of the branches is identical with that in the genus Pachypora, except in cases where there is a peculiar central tube (Natalophyllum tubiferum n. sp.). The structure of the peripheral zone is extremely distinctive and characteristic of the genus. There, strongly developed sclerenchyma separates the corallites, forming concentric layers. In it are situated pore canals along the generatrices and along the concentric circumferences of the cylindrical branch of the colony. In addition, there are radial canals or corallites (?), as if transformed into coenenchymal tubes. All the canals have tabulae, as do the corallites.

Genotype of the genus—Natalophyllum giveticum n. sp.

According to observations made in 1933, all the species of the genus were probably encountered in the 2nd quarry of Shcherbinovka, as was the species found by me there and not described here, with a lamellar form of colony (N. explanatum n. sp.).

31. Natalophyllum giveticum n. sp.

(Pl. II, figs. 9, 10; Pl. V, fig. 5).

External structure.
The holotype of this species is specimen a 43. This coral occurs in rather thick branches with a diameter of 20–26 mm¹. The length of the branches is unknown, since only fragments not more than 4 cm long are available. On the surface of the branches fairly large meshes are visible, 0.3–0.9 mm long and 0.25–0.5 mm wide. Their number per 1 cm² is 380–530. The external appearance of the meshes recalls Alveolites. The thickness of the walls of the meshes is 0.1–0.2 mm.

The internal structure of this coral is quite peculiar; in this respect it is sharply divided into two zones, inseparably connected with one another but of profoundly different structure: the central and the peripheral.

The central region in the available transverse section of a branch is 11 mm long and 2–3 mm wide. The corallites composing it (about 100 in number) have a rounded cross-section of the visceral chamber, owing to the deposition of concentrically layered sclerenchyma. The diagonals of the corallites here vary rather sharply—

…are, evidently, connected with the age of the corallites: from 0.9 mm to 0.4 mm. In 1 cm² of cross-section there are counted here about 375 corallites, while 1 cm in the same section intersects 15–20 corallites.

Pores are very clearly visible in both sections. The shape of the pores is round or elliptical. The diameter of the pores is 0.15–0.25 mm. On the wall of a corallite there is room for only one row of pores. The distance between neighboring pores of a row is 0.5–0.65 mm.

Tabulae are straight or often concave upward and sometimes obliquely arranged. The distance between them varies within wide limits from 0.15 mm to 2.5 mm (usually 0.6 mm). Squamae are absent; spines are likewise absent or occur very rarely.

The walls have a thickness of 0.15–0.4 mm. In addition to the already noted concentric structure, they also exhibit a radial one. The microstructure of the walls reveals interesting details. The light central band, 0.01–0.04 mm thick, nevertheless, under strong magnification, breaks up here and there into two parts. Then follows the wall proper, yellow-brown in color and with a concentric structure; it sometimes repeats the sharp angles—edges of the prisms, and sometimes slightly smooths them. The thickness of such a double wall is 0.15 mm. Finally, the latest deposit of sclerenchyma is a light-yellowish layer, which not only envelops the walls from within but also, entering the pores, fills them; this can in no way be said of the yellow-brown layer. If the latter was formed when the functions of the pores were still needed by the organism, then the yellowish layer was evidently deposited when the purpose of the pores had already been fulfilled. And still later, on this layer of light-yellowish sclerenchyma, tabulae were formed, as is clearly visible in longitudinal section.

The external zone of the coral, by its very curious structure, is a distinctive character of the genus. The corallites composing the central region turn sharply, almost at a right angle, and emerge perpendicular to the outer surface of the coral. At the same time, upon leaving the central zone, they are as if lost in the coenenchyma, in which they are observed, in the form of comparatively rare isolated corallites, with almost their former properties. Their internal diameter decreases somewhat (to 0.25–0.35 mm). The distance between the tabulae is 0.15–1 mm (on average 0.5–0.7 mm). In all, about 20–25 such corallites are observed in the area of the cross-section of the coral.

These corallites, as has already been said, are lost in the complexly structured mass surrounding them. In it, first of all, a concentric structure is observed, caused by traces of growth, i.e., by differently colored layers of sclerenchyma, and then by concentric zones of sinuous pore canals. In addition, in the same sclerenchymal mass there are also noticeable radially directed lines—especially at the periphery of the coral—among the visceral chambers of the corallites (?), completely filled with sclerenchyma. The diameter of these chambers is usually 0.05–0.15 mm. In places one can also observe the radial arrangement of the structural elements composing the substance itself, i.e., the concentric deposits of sclerenchyma. In addition, at the very periphery, where the microstructure of the sclerenchyma is especially clearly visible, it is evident that the walls which bounded the cavities of the corallites (?) now filled with sclerenchyma have the usual structure for them (in longitudinal section) of layers laid one upon another and intersecting at an acute angle at the edges of the calyx.

There are 7 of the mentioned zones of pore canals; moreover, the canals are arranged in these zones along the generatrix of the cylinder, and then in a perpendicular direction, i.e., along concentric circles of the transverse section of the branch. The pore canals have partitions (tabulae), as do corallites, and these partitions are arranged across the pore canals¹; they are sometimes straight, sometimes curved; the distance between them is about \(1/4\) mm (0.1–0.8 mm). The diameter of the pore canals in the peripheral zone is abnormally small: 0.05–0.1 mm; deeper inward it is 0.1–0.2 mm. Thus, the pore canals are comparable in size with the corallites (?), filled (though not everywhere) with sclerenchyma; in places even the direct transition of one into the other is visible. On the other hand, in size they differ sharply from true corallites, which emerge directly from the central zone of the coralla. Thus, a dimorphism is observed here, characteristic of some bryozoans or, for example, of Heliolites. Therefore it is rational to separate such forms into a special genus representing a specialized branch of the genus Pachypora.

Where exactly this species occurs in the Lebedyan Devonian is not precisely known.

32. Natalophyllum tubiferum n. sp.

(Pl. II, figs. 11, 12; pl. V, fig. 3.)

External structure. The holotype of this species is specimen a 41—a fragment of a branch 60 mm long and 10–20 mm in diameter. On its surface rather large and wide loops are visible, a characteristic external feature of the genus Natalophyllum. The number of such loops per 1 cm² is 270–440. Their length is 0.4–1 mm, and their width 0.25–0.5 mm. On the walls of the loops, 0.05–0.2 mm thick, spines are clearly visible in places. The transverse section of the branch is rounded-quadrangular.

As to the internal structure, an outstanding feature distinguishing this species from the others is the presence of a special cylindrical tube. This tube has an almost round transverse section with a diameter of 1 mm. Surrounded by 9 or 10 corallites, in longitudinal section it proves to be connected with the corallites by pores and to contain rare tabulae; only 2 such tabulae are visible over a distance of 0.5 mm; in the remaining part of the tube, 3 mm long, they are not visible. The distance between the pores is 0.75 mm. In addition to these large pores, with a diameter of about 0.25 mm, there are also small pores with a diameter of 0.05–0.1 mm, which connect the tube with the corallites and which are arranged on their walls in 1 or 2 rows (?). The inner surface of the tube has irregular projections, which, at least in part, represent blunt short spines. In the upper part of the longitudinal section the tube apparently passes into 2 corallites, being divided by a longitudinal wall.

In addition to the described tube, the presence of which makes it possible to see in N. tubiferum a representative of a special group or subgenus, this species differs from N. giveticum in the details of its structure in the other parts as well.

Characteristic is the small diameter of the central zone (3–3.5 mm) and, correspondingly, the small number (12–17) of its corallites, which run parallel to the axis of the corallum branch. Their diameter is 0.25–0.5 mm. Their walls

Izvestiya TII, vol. 56, no. VI, 6.

thickened (up to 0.04–0.25 mm) by structural sclerenchyma, owing to which they have acquired an oval or elliptical transverse section.

Round or elliptical pores with a diameter of 0.15–0.2 mm are spaced 0.75 mm apart, and sometimes 0.5 mm apart.

The distance between the floors is 0.3–1.5 mm. Spines are absent.

As for the peripheral zone, there the diameter of the corallites is 0.3–0.5 mm, reaching 0.7 mm, i.e., on average greater than in N. giveticum. The distance between the floors varies from 0.1 mm to 1.7 mm, on average about 0.9 mm. The distance between the pores along the axes of the corallites is 0.7–0.9 mm. In other respects no notable differences from N. giveticum are observed.

In which horizon of the Lebedyan Devonian this species was found has not been definitely established.

33. Natalophyllum giveticum var. elegantula nov. var.

(Pl. II, figs. 13, 21; pl. V, fig. 6).

External structure. This variety is almost identical with the principal form, differing from it only in external characters by having smaller and not very narrow loops on the surface of the coral and by certain details of the internal structure.

The holotype of this variety is specimen a 44—a fragment of a branch at its fork, with a diameter of 16–22 mm (25 mm before branching). On the surface of the branch one can observe loops 0.4–0.9 mm long and 0.3 (0.1–0.5 mm) wide. There are about 350 of them per 1 cm². The walls separating the loops have a thickness of 0.1–0.2 mm. Small spines are visible here and there.

Internal structure. The number of corallites in the central zone is about 70. Their diameter is 0.3–0.75 mm. The distance between the pores is 0.6–0.8 mm, rarely even 0.45 mm.

The diameter of the corallites in the peripheral zone is 0.2–0.3–0.4 mm. The horizon from which a 44 comes is unknown.

34. Coenites fascicularis n. sp.

(Pl. III, figs. 7, 8).

External structure. This species is represented in the Lebedyan collection by fragments of a branching colony, one of which (a 46), chosen as the holotype, has a length of 32 mm and diameters of a slightly elliptical section of 7.5 and 9 mm. On the surface of the branch are visible narrow slit-like mouths of cells, 0.25–0.4 mm long and 0.05–0.15 mm wide. There are about 350 of them per 1 cm² of surface. The distance between them is 0.3–0.6 mm.

Internal structure is characteristic of Coenites. In transverse section of the branch about 215 corallites are visible. In the center, about fifty of them occupy an area about 1.2–2 mm in diameter. There they have comparatively thin walls, 0.02–0.1 mm thick, with short spines on them; moreover, some corallites have a completely polygonal visceral chamber; however, even here the rounded-polygonal form of the transverse section predominates, owing to the deposition of stereoplasm. This process then develops rapidly and leads to the fact that, in an intermediate zone about 2 mm wide,

visceral chambers, when circular in section, have a considerably smaller diameter (0.3–0.4 mm) than in the center, and that they are separated by intervals several times exceeding their diameter. In this part the corallites are connected by pores with approximately the same diameter as that of the corallites.

In longitudinal section it is evident that the corallites approach the surface at an angle of about 40–50°. Here one may ascertain that the width of the transverse section of the visceral chambers in the peripheral zone does not exceed 0.15 mm, while the undistorted length is obtained in a transverse section of the branch, where it is equal to 0.2–0.6 mm, on average 0.3–0.4 mm. Pores (pore canals) in this peripheral zone, which is about 1.5 mm wide, have partitions (floors) and are arranged, in horizontal section, around the circumference, and in vertical section—parallel to the generatrix of the cylinder, i.e., obliquely to the axis of the corallites. The diameter of the pores here is 0.07–0.13 mm, and the distance between neighbors along the corallite is 0.7–1 mm. The vertical distance between pores in the central zone is equal to 0.5 mm.

Spines, noticeable in all zones, are especially clearly visible in the zone of compressed visceral chambers. They appear to form vertical rows, with the distance between neighboring spines being 0.1 mm or slightly less (0.07 mm).

Floors are clearly visible in all zones. They are sometimes straight, sometimes bent upward, and in the peripheral zone are sometimes convex. Often they are arranged not transversely, but obliquely with respect to the axis of the corallites. The distance between floors varies from 0.05 to 2 mm, with especially large distances observed in the central zone, where the corallites deviate only slightly from the axis of the branch. In other zones this distance does not exceed 2/3 mm.

Reproduction of the corallites occurs either by lateral budding, or by calicular division (?), but not by the appearance of a young corallite at the site of a rib.

From the most closely related Coenites tenellus Gürich our species differs in the large size of the corallum, as well as in other characters. The holotype of Coenites fascicularis comes from the vicinity of the village of Lebedyanskoye.

35. Neoroemeria nov. gen.

(Pl. II, figs. 14, 17, 18; Pl. III, figs. 12, 13, 18).

Diagnosis of the genus. Neoroemeria forms subcylindrical and parasitic colonies, or colonies growing upon extraneous objects.¹

Internal structure is extremely characteristic. In this respect the central part of the colony repeats the characters of the genus Roemeria. The peripheral part, however, is completely different. Here the structure strongly recalls that of the genus Chonostegites Edwards et Haime; however, whereas in that genus Nicholson’s connecting floors (connecting concentric plates) are separated from one another by some distance, in Neoroemeria they completely fill the entire space between the cylindrical corallites, forming a true coenenchyme. Also characteristic of our genus are vertical discontinuous plates situated between the connecting floors.

¹ If the species Neoroemeria (?) parasitica n. sp. is considered the genotype of a new convergent genus Neoroemeria, then the latter form of colony is unknown in Neoroemeria.

Comparison with related genera. The fortunate circumstance that, in representatives of the genus Neoromeria, dimorphism in the internal structure has been preserved makes it possible to speak with complete confidence of the origin of this genus from forms of the genus Roemeria. However, the difference between them, if one takes not the young but the adult stage of colonies of the genus Neoroemeria, is enormous. At this stage the structure is such that, by a morphological (and not genetic) character—namely, by the presence of true coenenchyme—we would have to assign this genus to the family Calapoeciidae. The family Calapoeciidae, which I propose to separate from the family Favositidae, is characterized precisely by the presence of coenenchyme, as is especially well observed in the genus Calapoecia Bill. Only the structure of the coenenchyme in the genus Neoroemeria differs rather strongly from that in Calapoecia. It is especially necessary to emphasize the presence in this coenenchyme of curved septa, characteristic of the connecting tubes of the family Syringoporidae. This once again emphasizes the origin of the genus Neoroemeria from forms belonging to this family, whereas the genus Calapoecia evidently arose from one of the species of Favosites or from some common root of the families Favositidae and Calapoeciidae. Therefore, it seems to me more correct to regard the genus Neoroemeria as a representative of a new family, analogous to the family Calapoeciidae, but having both a special origin and a different geological distribution. Whereas the family Calapoeciidae exists in the epoch of the appearance of tabulates, the new family (Neoroemeriidae), with its only representative so far, the genus Neoroemeria, appears only in the Middle Devonian (probably only in its upper part); the latter is natural, since the genus Roemeria is known only in \(D_{1-2}\).

In connection with the presence in the Lebedyanskaya fauna of the species Neoroemeria (?) parasitica n. sp. and Chonostegites parasiticus n. sp., it is especially interesting to compare the genera Neoroemeria and Chonostegites Edw. et Haime. The presence of the two species mentioned seems to me to point clearly to a second line of development, which produced forms that at first glance are identical with forms of the genus Neoroemeria. Such was my first impression. Now, however, doubt arises, and the thought appears that we are dealing with an interesting manifestation of convergence and that, consequently, Neoroemeria (?) parasitica n. sp. is the genotype of a distinct genus, derived not from Roemeria but from Chonostegites. In view of the fact that the material I have studied, relating to such forms, is limited, I for the time being leave Neoroemeria (?) parasitica n. sp. within the genus Neoroemeria.

Its genotype, naturally, is Neoroemeria westsibirica n. sp.

According to observations in 1933, the genus Neoroemeria was encountered in the lower part of the limestones of the quarry of the village of Lebedyanskoye (large massive colonies) and in the Shcherbinovka quarry (large massive, as well as branching forms).

36. Neoroemeria westsibirica n. sp.

(Plate II, fig. 17).

External structure. This peculiar form is represented by fragments of an apparently branching colony. The diameters of the branches—judging from these fragments—reached, in elliptical cross-section, not less than 20 and 35 mm. On the surface of the branches are visible round mouths or calices of corallites with a diameter of about 1–1.5 mm. There are about 35 of them per \(1 \text{ cm}^2\). The edges of the calices of the corallites rise above the general surface of the corallum by 0.3–0.5 mm.

The internal structure of this species differs sharply in the peripheral and central zones. In the central zone, with a diameter of about 1 cm, where the corallites, with a diagonal of 1.8–2.2 mm (in adults), are almost parallel to the axis of the branch, and where there are about 30 of them in cross-section,¹ they are in close contact with one another, as in Favosites. The internal structure here repeats the structure of species of Roemeria.

The double walls are pierced by pores. The diameter of the latter is 0.12–0.2 mm. The pores are situated on each wall in 1 or 2 rows; the distance between neighboring pores of a row is 0.7–0.8 mm.

The walls of corallites, both young and adult, intermingled with one another, have a radial-rayed and concentric structure of sclerenchymal deposits. Owing to these deposits, the cross-section of the visceral chambers is rounded,² and does not exceed 1.2 mm in diameter, while the thickness of the double walls reaches 0.9 mm.

The tabulae, as is seen in cross-section, are of the same character as in the outer zone of the coral; owing to their strong downward curvature, in cross-section they give 2–5 concentric, partly incomplete circles.

Spines are present in the central region, but they have the character of broad, blunt, and low (0.05–0.15 mm) projections of sclerenchyma. In one place in the thin section there are 11 such projections (in cross-section of a corallite). But in some sections of corallites they are absent.

We pass next to the description of the peripheral zone, which forms the greater part of the coral. According to the diagnosis of this new genus, it consists of corallites separated by intermediate tissue homologous to the coenenchyme of Heliolitidae and almost identical with the connecting tissue in the genus Calapoecia.

The corallites here are cylindrical, with an external diameter in adults of 1.5–1.7 mm. The distance between adjacent corallites varies from 0 to 1 mm. Per 1 cm² of cross-section there are about 23 corallites.

The walls of the corallites are pierced by round pores with a diameter of 0.17 mm. The pores are arranged in vertical rows. The number of rows of pores around a corallite is not less than 4. The distance between neighboring pores of a row is 0.4 mm.

The tabulae in the corallites are typical for Syringoporidae. But here they are rarely funnel-shaped and usually only slightly bend downward, approaching the tabulae of Favosites; even complete transverse tabulae occur, resting on the walls and only slightly curved. The distance between tabulae in such a case is 0.2–0.3 mm.

The walls of the corallites are rather thick; their thickness varies from 0.05 mm to 0.3 mm (rarely to 0.4–0.5 mm). Their microstructure is the same as in the central zone.

The spines are clearly visible. Their number in cross-section reaches 12. Their length is at most 0.12 mm. Whether they are arranged in vertical rows is not clear. It appears that spines are also present on the tabulae.

The intermediate space between the corallites is subdivided primarily by concentric, comparatively thick, sometimes undulately curved, almost nowhere interrupted

¹ Per 1 cm²—about 35–40 corallites.
² Even with a corallite diameter of 1 mm, the perfectly round section of the visceral chamber is only 0.3 mm.

plates, only rarely resting against one another. Their thickness is 0.05–0.1–0.2 mm, and the distance between them is 1/4–1/2 mm, varying from 0.2 mm to 0.9 mm. Near the corallites these plates rise by 0.2–0.5 mm. The intervening space between the plates, into which the pores open, is filled with thin (0.01–0.03 mm), curved partitions, entirely analogous to the tabulae of corallites; they are arranged now transversely, now longitudinally, but more often obliquely with respect to the plates.

In addition, between the plates there are supports which in radial section appear as columns; but a tangential section, perpendicular to the corallites, shows that these are now straight, now curved, dark-colored plates, which only in places resemble columns with an elongated transverse section. These plates mark out polygonal fields, in the middle of which there is a corallite. In places they are sharply interrupted; possibly these are pores in these plates. On the sides of these radial plates spines or ribs are often visible. Finally, it should be noted that these radial plates do not pass through several concentric plates along a single straight line (i.e., they do not give a structure of the genus Actinostroma).

As the holotype of the species Neoroemeria westsibirica, specimen α73 from the vicinity of the village of Lebedyanskoye has been selected.

37. Neoroemeria westsibirica var. cylindrica n. var.

(Plate II, figs. 14, 18).

Diagnosis. This variety, the holotype of which is specimen α74, differs from the principal form in the cylindrical branches of the colony (40–48 mm in diameter), in the smaller diameter of the corallites (equal to 1–1.2 mm), and in the lesser development of the intervening tissue, owing to which the distance between the corallites is less than their diameter; they often touch one another, and also 35–56 corallites are counted on 1 cm² of surface.

In the central zone, in its transverse section, there are about 50 corallites, the diagonal of which reaches 2.2 mm.

In the peripheral zone, owing to good longitudinal sections of the corallites, it is clearly visible that the tabulae are intermediate in type between those of Favosites and Syringopora. Rarely are they completely straight and horizontal, but usually they are arc-shaped, with the concavity directed upward. At the same time they are often incomplete and arranged obliquely, and sometimes almost vertically. The distance between the tabulae is 0.05–0.5 mm, on average 0.2 mm.

The diameter of the corallites is usually 1–1.2 mm. In places spines are visible on their walls, arranged in vertical rows¹; the distance between individual spines of a row is 0.15–0.5 mm (usually 0.25 mm). The vertical distance between the pores of the cylindrical corallites varies from 0.5 (0.25?) mm to 1.5 mm.

The distance between the concentric plates is 0.3–1 mm (on average 0.4–0.6 mm).

Radial plates, as well as interlamellar “tabulae,” are also present in this variety.

Specimen α74 comes from the 2nd quarry of the Shcherbinovskaya mine.

38. Neoroemeria (?) parasitica n. sp.

(Pl. III, figs. 12, 18; Pl. V, fig. 1)

External structure. This coral forms parasitic colonies, which in the specimens present in the collection reach 15 mm in thickness. On the surface of the coral the mouths of round corallites are visible, with a diameter of 0.9–1 mm. The distance between them is 0.1–1 mm. There are about 45 of them per 1 cm². In some places as many as 12 spines are visible in the calyces, the length of which is 0.2 mm.

Internal structure of this species is characterized by a strong development of sclerenchyma and by tabulae, which have the usual appearance for Syringopora.

Pores or pore canals, connecting the corallites with the mass surrounding them, have a diameter of 0.12–0.25 mm (occasionally up to 0.5 mm). These pores are probably arranged in vertical rows, with a distance between neighboring pores of a row of 0.6 mm (from 0.4 mm to 1 mm). The number of rows around each corallite has not been established. The length of the pore canals depends on the distance between the corallites that they connect. Within the canals there are partitions, placed now transversely, now more rarely longitudinally. Since these partitions, identical with the tabulae of the corallites, are often arcuately curved, in transverse sections of the connecting canals there is observed a picture resembling the transverse section of the corallites of syringoporids.

The tabulae of the corallites show a certain regularity in their arrangement; namely, some of them, having in longitudinal section the appearance of vesicles, are situated along the walls or are very steeply inclined. In places these vesicles fill the entire visceral chamber, but more often they leave a space between them, where horizontal, straight, and more often strongly upward-concave tabulae are located, with a distance between them of 0.05–0.6 mm. In places these true tabulae completely displace the vesicles, occupying the whole visceral chamber. On the tabulae spines are visible here and there.

Spines are also present on the walls of the corallites; there they form vertical rows, with a distance between neighboring spines of a row of about 1/4 mm. The number of rows of spines in the corallites is probably 12, judging from the transverse section of the corallites. The length of the spines is 0.2–0.3 mm, i.e., in places it exceeds the length of the semiradius.

The connecting tissue between the corallites breaks up into separate concentric layers of sclerenchyma, 0.4 mm to 1.5 mm thick (on average 0.8 mm). These layers are substantially composed of sclerenchyma. In the latter, besides the corallites penetrating it and the connecting tubules associated with them, other cavities are also observed, apparently representing remnants of the filling of the interlamellar space by sclerenchyma. This is proved by the fact that in them we find not thin curved “tabulae,” but thick partitions directed parallel to the corallites and, evidently, analogous to the radial lamellae of Neoroemeria westsibirica.

As is evident from the description given, Neoroemeria (?) parasitica, apart from its mode of growth and dimensions, differs very substantially from the preceding species of Neoroemeria: 1) by the absence, in the initial stage of growth of the colony, of the Roemeria stage, 2) by the strong development of deposits of structureless stereoplasm, 3) by the syringoporid type of tabulae within the corallites. These differences are so significant that—

Neoroemeria (?) parasitica is a representative of a special group¹.

As the holotype of the species Neoroemeria (?) parasitica there has been selected specimen α 75 with the corresponding thin sections, originating from the Alchedat River somewhat above the Kamenushka River.

39. Chonostegites parasiticus n. sp.

(Pl. II, figs. 15, 16).

External structure. This species forms parasitic colonies; in particular, specimen α56 from the vicinity of the village of Lebedyanskoye, selected as the holotype of Chonostegites parasiticus², is a parasitic formation on a branch of a pachyporid; the thickness of this growth in the present case is 16–17 mm. The density of corallites in the colony has not been determined, since the surface of the coral is covered.

Internal structure. The colony consists of corallites having a diameter of 1–1.3 mm, and of connecting plates (floors, after Nicholson) more or less curved concentrically with respect to the surface of the colony. In the holotype there are 7–9 such plates.

The corallites, beginning in the basal part of the colony, at first run horizontally, and then turn sharply and assume a vertical position. The same phenomenon is also observed in the later stages of coral growth, when a corallite, originating within the connecting plates, at first runs horizontally, then turns and becomes vertical, emerging from the connecting plate. At the same time the newly appearing corallite, if not always, then in some cases is connected with another, maternal corallite. Thus, reproduction takes place by lateral budding. The corallites pass through several plates, connecting them; but it is doubtful whether each of them, or at least some of them, pass through the entire colony; at least, in a radial section of the colony not a single such corallite is visible, which may also be explained by the curvature of the corallites.

The walls of the corallites have a thickness of 0.2–0.35 mm. They continue also into the connecting plates, separating the corallites there, and are interrupted between them only in places where pores are present or where new corallites branch off.

The tabulae within the corallites are in places completely horizontal, while in other places of the same corallite they are typical funnel-shaped ones, or even with an axial canal, subdivided by horizontal partitions. There are, of course, also tabulae of an intermediate form. In the case of straight horizontal tabulae the distance between them is 0.1–0.4 mm (on average 0.12–0.25 mm). Horizontal tabulae are observed chiefly in the upper part of the corallites, where they end or where their growth was periodically suspended³.

In addition to tabulae, spines are clearly observed inside the corallites; they form vertical rows. The distance between neighboring spines of a row is approximately 0.3 mm. There are probably 12 such rows around the corallite.

The structure of the plates is characterized by rather great complexity and irregularity. Walls and po—

plates, filling the cavities inside the laminae. These cavities, owing to their irregularity, are difficult in each case to assign to one or another element of the colony; but in many cases, if not always, these are the initial, creeping parts of the corallites and their connecting tubules. In places, in these cavities, besides tabulae, spines are also visible. The tabulae have, in general, the same character as in the corallites. They are arranged sometimes along the tubular cavities, sometimes across them; in the latter case they are convex, and therefore in transverse section of the cavities they give concentric circles. The internal diameter of the connecting tubules between the corallites is about 0.25 mm. The space between the cavities inside the connecting laminae is filled with the same structureless substance (stereoplasm) as the upper and lower walls of the laminae. However, this lack of structure is only a consequence of poor staining of the skeletal substance, for in places both concentric and radial structure are visible, both within the walls of the corallites and in the connecting laminae.

It must be noted that in places the connecting laminae described overlap one another without any intermediate space, although in other parts of the colony the same laminae diverge. This is important to note because, in its structure, the present species thus gives a picture transitional from the typical Chonostegites to the new genus Neoroemeria (in the form in which it was adopted for N. (?) parasitica).

1. Aulocystis (?) cornigera Schlüter.

(Plate III, fig. 19).

1. Aulocystis cornigera Schlüter. 20, p. 162, pl. XVI, figs. 8–10.

The genus Syringopora is absent from the large collection from the vicinity of the village of Lebedyanskoye. Only a careful examination even of small pieces revealed 3 fragments of corallites (15–20 mm long) belonging, possibly, to the genus Syringopora. However, these fragments, whose locality is not precisely known, should rather be assigned to the genus Aulocystis Schlüter, as is indicated by the isolated occurrence of the fragments.

On the surface these fragments are covered with fine sharp growth wrinkles and longitudinal ribs. The latter, as well as weak grooves, number about 40 around the corallites.

The internal structure is characterized by the presence of funnel-shaped tabulae, which also enter the connecting processes, as is visible on one of the fragments. In addition, spines are also observed on the tabulae and walls. On the walls they are combined into vertical rows (40 in each corallite), forming false or rudimentary septa. The vertical distance between the spines is approximately 0.25 mm.

If the fragments described belonged to the genus Syringopora, then, by their diameter (5–6.5 mm), they would be assigned to one of the representatives of the Syringopora nobilis group, characterized by large corallites and including the species: Syringopora nobilis Bill., (?) S. abdita De Vern., S. bellensis Eth., S. eifeliensis Schl., S. laxata Billings, S. spelaeanus Eth. and S. verticillata Gdf. The diameter of the corallites in all is 5–7 mm. The vertical range of the group is S₂—D₁—D₂. The horizontal distribution is Western Europe, America, and Western Siberia. It is interesting to note that reliably known representatives of this group have not been recorded above D′₂. Our specimens may belong—

…be considered S. nobilis Bill. or S. eifeliensis Schl., originating from \(D_2^1\). It is more natural, however, to see in the described fragments representatives of Aulocystis cornigera Schlüt., since these fragments were found isolated in different places, which is less probable for the comparatively compact coralla of syringoporids.

As for the details of the structure of A. cornigera Schlüt., they are the same as in its Lebedyanskoye representatives, the plesiotype of which is specimen \(a53\); the comparison remains, however, incomplete, for we do not know the number of rows of spines in Schlüter’s species, on the one hand, and on the other—the form of the corallum of the Lebedyanskoye form is also unknown¹.

41. Vermipora ? sp.

This species is represented by only one specimen—\(a86\),—which has been selected as the holotype. The latter is a thin parasitic colony with the following external characters. Its incomplete width and length are 20 and 30 mm. The thickness, or height, of the colony is about 1 mm. The corallites of the colony are covered with an epitheca bearing fine concentric striae; lying close to one another, they diverge fanwise from an imaginary axis of symmetry and form a continuous parasitic encrustation in the form of a layer; each corallite, as a rule, gives rise to two new ones; in this process the calice of the parent corallite rises upward. The length of the corallites is 2.5–3 mm, and the diameter of their calice is about 0.6–0.75 mm. The maximum diameter of the corallite itself often slightly exceeds 1 mm (1.1–1.3 mm).

As for the internal structure, in the mouths of some calices there are visible ceilings convex upward (floors of the calices?). The assignment of this species to the genus Vermipora is doubtful, since a creeping form of colonies is not known for this genus. However, Lindström described from \(S_2\) one creeping form, namely Favosites clausus, which Nicholson assigns to the genus Vermipora. If this is correct, then the assignment to this genus of the Lebedyanskoye form, very similar in external appearance to Lindström’s species, is also correct.

The holotype of this species comes from an outcrop on the right bank of the river Malyi Kitat, below the cattle yard, beyond the ravine, where the river begins to turn slightly to the NW. The specimen was found by Prof. M. A. Usov.

Monticulipora (?) concentrica n. sp.

(Plate IV, figs. 4, 5).

This interesting species is represented in the collection only by a fragment of a colony, from which its height was more than 25 mm and its diameter more than 55 mm (probably not less than 10 cm). The external surface has not been preserved.

The internal structure is characterized by an extremely clearly expressed feature characteristic of this species: both in tangential and in radial sections there is visible a distinct layering of the colony, expressed in the periodic alternation of narrow dark and broader light bands. Whereas the broad bands in vertical section have a width of \(^{1}/_{4}\)—\(2^{1}/_{4}\) mm (usually 1 mm), the narrow ones—only

0.1–0.7 mm (often 0.4 mm) and differ from the normal structure of the former by the complete filling of the zooecia (between 2–3 diaphragms) with stereoplasm. This filling begins and ends very abruptly: the zone of stereoplasm is bounded above, and often also below, by horizontal diaphragms. However, below, more often, the stereoplasm develops not by such a jump, but after a certain preliminary thickening of the walls; the stereoplasm itself forms with its lower boundary an upward-convex vault or even a blunt cone. Within the zone of stereoplasm development, here and there nearer its upper boundary there remain unfilled areas, either isometric or in the form of a rocket with its tail directed downward. In a tangential, somewhat oblique section, deposition of stereoplasm gradually changes the polygonal and rounded-polygonal section of the cells to a circular one, the diameter of which then decreases until it disappears.

The diagonal of the zooecia varies from 0.15 mm to 0.45 mm, averaging 0.35 mm. In an area of 1 cm² they number 1080–1840. The figure 1840 was obtained in one area with especially small zooecia. A 1 cm line in transverse section intersects 25–30 zooecia.

The tabulae in our species are very thin (0.01–0.02 mm), perfectly straight or very slightly curved and horizontal; the distance between them is rather uniform, but varies from 0.05 to 0.5 mm, averaging 0.25 mm.

A section transverse to the zooecia reveals the presence of small spines, or rather tubercles, situated on the walls. They stand out distinctly only outside the zone of intensive development of stereoplasm.

The walls of the zooecia vary in thickness from 0.01 mm (usually from 0.05 mm) to the maximum value of a half-diagonal, when the stereoplasm fills the entire cell. Nowhere within the wall is a median line noticeable separating adjacent zooecia. On the other hand, another structure is visible, resembling pores: namely, in transverse section of the zooecia the walls appear to be intersected by such connecting canals. However, these “canals” are very indistinct, filled with material of the same color as the walls; therefore it is not clear whether they really were pores. More likely this is a structural feature of the wall substance. There are 8–9 such canals around a cell.

Reproduction in this species takes place by division.

The holotype of Monticulipora (?) concentrica n. sp. is specimen α80, originating from the Mazalovsky Kitay River above Shcherbinovka.

The layered structure associated with the development of stereoplasm and the microstructure of the walls distinguish this species from all known ones. At the same time, it certainly does not belong to the genus Monticulipora in its new understanding, since our species lacks cystiphragms. Probably this species forms a new genus, which we do not yet distinguish.

STROMATOPOROIDEA.

Group Stromatopora korovini.

42. Stromatopora korovini n. sp.

(Pl. I, figs. 2, 3; pl. III, fig. 16; pl. IV, fig. 1).

External structure. In the collection studied there is one fragment of a coenosteum, so different in its properties from other species of stromatoporoids that this fragment is sufficient for distin—

of the establishment of a distinct new species, to which I have given the name in honor of my deeply respected teacher, Prof. M. K. Korovin. This fragment indicates the considerable dimensions of the coenosteum: its height exceeded 6 cm, and its horizontal dimensions were evidently much greater.

In the internal structure of the coenosteum there is observed a sharply expressed dimorphism—the chief character of the species being distinguished. This dimorphism is clearly visible precisely in radial section. There we see that the coenosteum is naturally divided into concentric layers of varying thickness, from 1 mm to 4 mm. Each of these layers alternately presents either the structure characteristic of a radial section, for example, of Stromatopora Beuthii Barg. (13, pl. XXIII, fig. 11), or, conversely, a structure without clearly expressed pillars (as, for example, in the lower part of fig. 3, plate XXII in the same monograph of Nicholson). Such a structure is by no means the result of an obliquely directed cut. In a less pronounced form it may also be noted in previously described species, e.g., in Stromatopora Carteri Nich. (13, pl. XXIII, fig. 1) and perhaps in Stromatopora Hüpschii Barg. (13, pl. XXII, fig. 3).

In view of the fact that this dimorphism is especially sharply expressed in the species described, it is natural to distinguish it as a typical representative of a new group of stromatoporoids—the group Strom. korovini.

The zones with the development of radial “pillars” are composed of these “pillars” and of partitions, convex to one side, separating the spaces between the “pillars.” In places these partitions are situated at the same level over considerable portions of the coenosteum. The distance between these partitions vertically varies from 0.05 mm to 0.6 mm. In 1 cm of vertical section (parallel to the layers) there are 35–40 “pillars.” The latter are quite often interrupted, join with one another, or branch. As a result of interruptions, completely isometric parts of “pillars” are sometimes obtained, and as a result of their union by beam-like projections the intermediate cavities between them here and there assume a completely isometric, round, or oval outline. Much more often, however, there occurs only a periodic narrowing of the intermediate spaces owing to the corresponding expansion of the “pillars.” The arrangement of the elements just enumerated at one and the same level, emphasized by the arrangement of the partitions at one level, and the presence of more darkly colored syngenetic elements of the skeleton—all this gives a clear stratification to the zones with “pillars.” Conversely, this stratification is hardly perceptible in the intermediate zones.

In the latter, the structure is irregularly reticulate both for the skeletal tissue and for the interspaces. However, the latter in places assume a regular round form instead of the usual worm-like one. On the other hand, in the skeletal tissue there is also observed in places, in addition to a certain stratification, the presence of radial “pillars” piercing this zone throughout. In general, porosity in it is greater than in the zones of “pillars,” and the partitions (tabulae) are apparently less developed.

The microstructure of the skeletal tissue is characteristic of stromatoporoids: at high magnification the porosity of the skeleton is clearly visible, while these pores are scattered in the skeletal substance, which consists of grains of different sizes.

Extremely characteristic is the tangential section of this species, showing the lamellar and worm-like character of the transverse section of the “pillars,” the thickness of these lamellae being 0.05–0.25 mm (on average 0.15 mm).

In both longitudinal and transverse (tangential) sections of the coenosteum, astrorhizal canals with partitions are clearly visible, with a diameter not exceeding 0.3 mm. In tangential section they form characteristic bundles. The number of main canals extending from the vertical axis is five. The astrorhizae are spaced 11–16 mm apart.

The holotype of Stromatopora korovini is specimen α95, originating from the Mazalovsky Kitay River above Shcherbinovka.

43. Stromatopora stylophora n. sp.

(Pl. I, figs. 5, 6; Pl. IV, fig. 2; Pl. V, fig. 2).

In the collection described there is only one specimen, α82, which comes from the quarry above Shcherbinovka and is the holotype of the above-named species. It differs from Stromatopora korovini by: 1) a greater development of skeletal substance in comparison with the intervening cavities; 2) a lesser expression of the principal character of the given group, although it is still quite sharply noticeable; 3) the development of special vertical pillars, differing from the others only in that the skeletal substance thickens along their axis; as a result, a clear axial line is indicated in longitudinal section, while in tangential section it corresponds to the appearance of true isometric pillars with a diameter of 0.25–0.35 mm and with a dark central spot (its diameter varies from 0.05 to 0.1 mm). These pillars are sometimes isolated, but in most cases are connected with the rest of the skeletal mass. In short, we have here a structure identical with that which Nicholson described and figured in his monograph (13, Pl. XXIII, fig. 10) as a characteristic feature of Stromatopora Beuthii Barg. In that species, however, the radial section is entirely different, owing to which Barga’s species belongs to an altogether different group of stromatoporoids, and not to the group of Str. korovini, to which Stromatopora stylophora n. sp. belongs.

44. Stromatopora (?) parasitica n. sp.

(Pl. III, fig. 4).

External structure. This species forms parasitic colonies; in particular, its holotype—specimen α55—represents a parasitic coenosteum about 7 mm thick. Its surface is poorly preserved, and therefore it cannot be said whether “mamelons” and astrorhizae are present on it.

Internal structure. In the greater part of the radial section the usual picture of concentric laminae and radial pillars is observed. The distance between the concentric laminae averages 0.2–0.3 mm, varying from 0.05 mm to 0.5 mm. The pillars usually do not pass through the laminae, and when some of them cross 2–3 laminae, this may be only a coincidence. The distance between neighboring pillars varies from 0.05 mm to 0.5–1 mm. The upper and lower ends of the pillars often widen in the manner of a stupa. In addition to the pillars, partitions are observed between the laminae, usually having the appearance of upward-convex bubbles; some of them, however, are concave or else obliquely arranged with respect to the laminae.

In radial section some laminae diverge strongly; in the wider space between them, reaching

1–1.5 mm, a special, peculiar structure develops—a characteristic feature of this species. It is observed almost everywhere at the base of the colony. Instead of radial pillars, there is here an irregular reticulate structure with very variable dimensions of the irregular “loops” of this network: from 0.05 mm to 0.5 mm in length. On the sides of these “loops” there are often projections resembling spines. Where a transition of the network into the normal structure is indicated, arc-shaped partitions and pillars also appear in these places.

The skeletal substance in this species seems structureless; thus, if this circumstance is not the result of poor preservation, then this species is not a representative of Stromatopora. In any case, it is a new form, not yet recorded in the literature.

The occurrence of Str.? parasitica n. sp. in the area of the village of Lebedyanskoye is not known exactly.

45. Syringostroma geba var.

(Pl. III, fig. 18; Pl. V, fig. 1).

External structure. The holotype of the variety—specimen α 75—is represented by a fragment of a coenosteum on which Neoroemeria parasitica n. sp. was situated. The height of the coenosteum was not less than 20 mm. There are “mamelons” with astrorhizae on them.

Internal structure in vertical section is characterized by the presence of astrorhizae, pillars, concentric laminae, and partitions. The skeletal substance has a microstructure typical of stromatoporoids.

The pillars in the given radial section intersect several laminae (in places not fewer than 10). The distance between them varies from 0.2 mm to 0.3–0.4 mm (on average 0.25 mm). Where the concentric laminae are weakly developed, periodic widenings are visible on the pillars at the points of intersection with underdeveloped laminae. The thickness of the pillars is 0.05–0.15 mm (on average 0.1 mm).

The distance between the concentric laminae varies from 0.15 mm to 1.5 mm (on average 1/3 mm). Greater distances are observed only in those places where the pillars are predominantly developed.

Both between the pillars and in the astrorhizal canals, partitions are observed—sometimes horizontal, sometimes oblique, sometimes straight, and more often convex upward. The distance between them is 0.05–0.3 mm, rarely more.

The diameter of the astrorhizal canals varies from 0.15–0.2 mm at the periphery to 0.7 mm near the center of the astrorhizae.

The heterogeneity of the structure of the coenosteum consists not only in the fact that in some places both concentric laminae and pillars are well developed, while in others only pillars are developed, but also in the fact that in places, in very small areas, neither the former nor the latter are developed. Thus, dimorphism is expressed here in an incipient degree, so characteristic of Stromatopora horovini n. sp. Such incipient development of this feature, as already mentioned, is observed in the species Stromatopora carteri Nich. and in Stromatopora hüpschii Barg. However, in neither the one nor the other is there any considerable development of concentric laminae, thanks to which in our species a regular network is observed, as in actinostromes. On the other hand, by the presence of the same network the described species stands very close to Syringostroma Strahlenbergi Yav. However, the conspicuous astrorhizal canals distinguish it. Exactly

also very close is the given Lebedyanskaya form to Syringostroma geba Yav., and it differs only in the finer network of the skeletal tissue and in some other details.

The insufficient study of our form does not allow us definitively to clarify its relation to Syringostroma geba Yav.

The holotype of this variety comes from the same locality as Neoroemeria parasitica n. sp.

46. Syringostroma obrutschevi n. sp.

(Table III, figs. 1, 2, 11).

External structure. This species occurs in the form of rather large flat cenosteums, not less than 18 mm high and not less than 15 cm in diameter. On the surface of the stock, “mamelons” are observed.

As the holotype specimen α83 from the vicinity of the village of Lebedyanskoye has been selected.

Internal structure. In radial section the structure of the cenosteum is clearly visible, consisting of concentric, wavily curved laminae and radial pillars. The distance between the former varies from 0.05 mm to 0.4 mm, averaging \(1/6\) mm. The thickness of the laminae is 0.02–0.1 mm. The radial pillars pass through the laminae, generally without interruption, sometimes crossing 10–15 laminae. Owing to thickening near their intersection with the laminae, in vertical section they recall an “hourglass structure,” or the longitudinal section of a ladder step; and the spaces enclosed between neighboring pillars and concentric laminae, in the same radial section, are round or rectangular if the mentioned thickening of the pillars is not expressed. The distance between pillars in radial section varies from 0.06 to 0.6 mm, usually equaling \(1/6\)—\(1/7\) mm. The number of pillars per 1 mm² is approximately 27. In tangential section the pillars appear not as circles, but as more or less isometric or elongated, sometimes isolated, sometimes coalescing spots with ragged edges, at times resembling the “arms” of an actinostrome. The diameter of the spots is 0.05–0.3 mm.

The microstructure of the substance of the pillars and laminae is granular: darker spots stand out against a generally lighter background, and at high magnification the intervals between the grains appear as if in the form of canals, somewhat recalling the structure of the skeleton of Stromatoporella.

Between the laminae there are also, in considerable number, partitions, often having the arcuate appearance of small bubbles or vaults between the pillars.

Here and there canals of the astrorhizal system are encountered in section, likewise provided with partitions. The diameter of their axial canal does not exceed 0.6 mm, and in the branches it is 0.3 mm (near the axial canal).

Among the known species of Syringostroma only five have been described: S. densum Nich., S.? ristigouchense (Spencer), S. tschichatschevi Yav., S. geba Yav. and S. strahlenbergi Yav.

The last three species were described by V. I. Yavorsky from the Middle Devonian of the Kuznetsk Basin and are closer to ours than the separate species of Nicholson. As for the Siberian species, among them only S. strahlenbergi Yav. approaches it in the dimensions of the skeletal elements, though they are nevertheless larger. But this species differs completely from the Lebedyanskaya one in the absence of astrorhizal canals, and

the other Siberian forms, by the coarser structure of the skeletal tissue. The species is named in honor of Academician V. A. Obruchev.

47. Parallelopora (?) minuta n. sp.

(Plate I, figs. 9, 10).

This peculiar species is represented in the present collection by two thin sections (α94) from a small coenosteum. The height of the latter was about 11 mm, and its diameter 16–18 mm. These thin sections—α94—serve provisionally as the holotype of the form described.

The character of the external surface is unknown, while the internal structure is characterized by the following features. In a radial section it is seen that the skeletal substance is almost continuous, without spaces between the horizontal concentric laminae; only in places are very small areas visible between them, in the form of dots filled with calcite. Also not filled with skeletal substance are the astrorhizal tubules, with a diameter of 0.15–0.3 mm, visible against the general dark background as small circles and sinuous canals, depending on the direction of the section. In these canals septa are clearly visible (in one thin section), with a distance between them of 0.1–0.2 mm.

There are on average 10–15 concentric laminae per 1 mm, with the distance between them ranging from 0.03 mm to 0.15 mm. The vertical elements of the skeletal tissue pass through several laminae. A tangential section shows that these vertical elements of the skeletal tissue are more or less isometric columns, with a diameter of 0.01–0.05 mm; in addition, it shows the presence of cylindrical vertical tubules, of which there are about 600 per 1 cm². The diameter of the tubules is 0.07–0.1 mm. The tubules have septa, with a distance between them of 0.07–0.3 mm. The interior of the tubules is for the most part filled with the same structureless substance (stereoplasm) as the spaces between the columns. The latter are colored a darker shade and, under strong magnification, reveal a punctate structure; i.e., in their structure they resemble the skeletal substance of Stromatopora. At the same time, in places they are more or less isolated.

No species close to the form described are known; its assignment to the genus Parallelopora is doubtful and is based on the identity of the types of microstructure of the skeletal substance in our species and in Parallelopora ostiolata Barg. (13, pl. II, figs. 6 and 7). It is possible that Parallelopora (?) minuta n. sp. constitutes a new type of form, transitional between Stachyodes and Parallelopora.

Parallelopora (?) minuta n. sp. was found in the second Shcherbinovka quarry.

48. Parallelopora (Stachyodes?) sp.

(Plate I, fig. 8; Plate V, fig. 4).

External structure. This species is represented in the collection by only a single small fragment of a branch (α81)—the holotype of the species, coming from the vicinity of the village of Lebedyanskoye. The diameter of the branch is 5–6 mm. On the surface of the branch are visible now elongated longitudinal, now round transverse sections of zooidal tubes. Their diameter is 0.1–0.15 mm; on 1 cm² of the branch surface there are about 1200 such round openings.

Internal structure is known only from a transverse thin section. Here, the axial tube, about 0.4–0.5 mm in diameter, and several of its branches of smaller diameter are very clearly visible. The skeletal substance around them is strongly thickened. There are likewise fairly numerous zooidal tubes 0.09–0.12 mm in diameter. Finally, apparently, there is also the fine tubulation characteristic of Stachyodes Nicholson, observed in the skeletal tissue. The diameter of these tubules of the 3rd order is 0.02–0.05 mm. These tubules are comparatively not numerous and do not show a clearly expressed parallelism with the zooidal tubes, as is characteristic of Stachyodes verticillata M’Coy. Such parallelism is observed only at the periphery of the transverse section, where within the skeletal substance dark and lighter bands are outlined, characterizing the microstructure of this substance. In the center of the branch, where these bands are cut across, it is evident that the dark elements (pillars) form in this section a network resembling a tangential section of actinostromes. Since Nicholson says nothing about the structure of the sclerenchyma between the “tubuli,” he probably did not observe anything similar to the microstructure described above. Therefore the Lebedyanskaya form apparently constitutes a new species, differing further from S. verticillata M’Coy by a two-times smaller diameter of the zooidal tubes. Even if Nicholson’s “tubuli” are regarded as homologous with the “pillars” described above, nevertheless our species differs from M’Coy’s species in the character of the transverse section of these elements: isometric in the latter, in the Lebedyanskaya form it more closely resembles the tangential section of Parallelopora ostiolata Barg. (13, pl. II, fig. 6).

49. Stromatoporella sp.

(Plate I, fig. 4; Plate III, fig. 3).

External structure. In the collection studied there is a fragment of a coenosteum—specimen α87, the holotype of this species, originating from the Alchedat River above the village of Lebedyanskoye. The diameter of the coenosteum, judging by the fragment, exceeded 8 cm, and its height was 2.5 cm.

Internal structure is characterized above all by the skeletal microstructure usual for Stromatopora: dark spots or grains of various size with lighter interspaces are clearly distinguishable, forming the semblance of a network of indistinct canals.

Concentric laminae are 0.05–0.3 mm thick. They are thickest around the astrorhizal canals. The distance between the laminae varies from 0.2 mm to 0.6 mm, averaging 0.3–0.4 mm.

Rather strongly developed radial pillars intersect, in places, several laminae (2–4). Their thickness varies from 0.04 mm to 0.25 mm, usually not exceeding 0.1 mm. The distance between the pillars varies from 0.1 mm to 0.4 mm, averaging 0.2 mm. At intersections with the laminae the pillars often widen; therefore the spaces between them in vertical section appear either round or elliptical, elongated upward. This also explains the presence of “stalactites” and “stalagmites” on the laminae.

Between the pillars, upward-convex tabulae are often visible; the distance between them is 0.07–0.3 mm. Sometimes they are incomplete, especially in the astrorhizal canals, where in places they have the character of small bubbles; the diameter of the canals reaches 0.7 mm.

The astrorhizal canals correspond to elevations of concentric plates, i.e., mamelons, but the length of the former is considerably greater than the diameter of the latter. It must be noted, however, that in radial section there are longitudinal sections of astrorhizal canals up to 5 mm long, above which there are no traces whatever of elevation of the horizontal plates. It is also of interest that the peripheral parts of the canals penetrate upward through 4–5 plates above their central part.

The absence of a tangential section does not make it possible to determine definitively the systematic position of this form, which is possibly new.

V. GENERAL CONCLUSIONS ON THE CHARACTER AND STRATIGRAPHIC SIGNIFICANCE OF THE DESCRIBED FAUNA.

As a result of the study presented above, we can give the following list of Devonian Coelenterata from the village of Lebedyanskoye:

RUGOSA.

Amplexus altaicus var. minor n. var.
Amplexus inconditus (?) Bill.
Aulophyllum (Duncania?) sp.
Acervularia davidsoni (?) Edw. et Haime.
Cyathophyllum (?) sp.
Diphyphyllum (?) tetrasticum n. sp.
Diphyphyllum strictum (Edw. et Haime).
Campophyllum dimorphicum n. sp.
Phacellophyllum (Diphyphyllum?) costatum n. sp.
Spinophyllum (?) sp.
Schlüteria rugosa var. westsibirica n. var.
Schlüteria rugosa var. minor n. var.
Schlüteria rugosa var. major n. var.
Schlüteria nalivkini n. sp.
Grypophyllum cylindricum n. sp.
Cyathophyllum (?) speciosum n. sp.
Neospongophyllum sp.
Dialithophyllum asiaticum n. sp.
Cystiphyllum senecaënse (?) Bill.
Cystiphyllum macrocystosum n. sp.

TABULATA.

Favosites helderbergiae var. mesodevonica n. var.
Emmonsia (Favosites) hamiltoniae Hall.
Emmonsia (Favosites) sibirica n. sp.
Pachypora cervicornis (?) de Blainv.
Pachypora cervicornis var. major n. var.
Pachypora dubia var. minima n. var.
Pachypora dubia Edw. et Haime.
Pachypora alveolitiformis n. sp.
Alveolites suborbicularis Lam.
Alveolites arbusculus n. sp.
Natalophyllum gen. nov.
Natalophyllum giveticum n. sp.
Natalophyllum tubiferum n. sp.

Natalophyllum giveticum var. elegantula nov. var.
Coenites fascicularis n. sp.
Neoroemeria nov. gen.
Neoroemeria westsibirica n. sp.
Neoroemeria westsibirica var. cylindrica n. var.
Neoroemeria (?) parasitica n. sp.
Chonostegites parasiticus n. sp.
Aulocystis (?) cornigera Schlüter.
Vermipora (?) sp.
Monticulipora (?) concentrica n. sp.^1).

STROMATOPOROIDEA.

Stromatopora korovini n. sp.
Stromatopora stylophora n. sp.
Stromatopora (?) parasitica n. sp.
Syringostroma geba var.
Syringostroma obrutschewi n. sp.
Parallelopora (?) minuta n. sp.
Parallelopora (Stachyodes?) sp.
Stromatoporella sp.^2).

The following table gives a brief characterization of the new species from the above list (p. 99), which will facilitate the use of the present work.

Analysis of the list of species given above, despite the multitude of new varieties, makes it possible to draw rather substantial conclusions regarding the stratigraphic position of the fauna studied.

If this analysis is begun with the lowest group of organisms, namely with the stromatoporoids, attention is first of all drawn, in the collection described, to the group Stromatopora korovini. In recent times two works by V. I. Yavorskii (24 and 25) have appeared, devoted chiefly to the Devonian Stromatoporoidea of the southwestern margin of the Kuznetsk Basin. However, there we do not find forms of this group. It seems to me that this is not accidental, since even in the rather considerable collections from Tomsk, from the same region, such forms have not been observed. Therefore we should rather connect the appearance in the Lebedyanskoye Devonian of this special group of stromatoporoids not with accidental local variations, but with a definite stage in the development of one of the groups of stromatoporoids. In the description of Strom. korovini n. sp. it was already pointed out that its characters are weakly indicated also in other Middle Devonian forms. Therefore the vivid expression of those same characters in the group Strom. korovini indicates, it seems to me, the stratigraphic position of this interesting group in the upper part of the Givetian stage. This can explain the absence of similar forms in the Givetian stage D₂ of the southwestern margin of the Kuznetsk Basin, where the coral facies is developed essentially in the lower part of this stage.

Passing further to the Tabulata, it should be noted that this group in the collection studied is represented, although by diverse forms, nevertheless far from completely. Thus, for some reason syringoporids are absent^3), as well as Heliolites.

^1) Monticulipora (?) concentrica is assigned here conditionally, since bryozoans in general have remained unstudied by me.

^2) Observations in 1933 show that this list by no means exhausts the entire diversity of forms of the Lebedyanskoye corals.

^3) My collections in 1933 discovered this genus both in the Shcherbinovka quarry and in the stone quarry of the village of Lebedyanskoye (fig. 1).

Species name	Mode of growth	\(N+n\)	\(D\)	\(d\)	Septa	Dissepiments \(n_1\)	Dissepiments \(n_2\)	\(r\)	Notes
I. Rugosa. Amplexus alticus var. minor n. var.	Solitary	\(43+43\)	—	36–41	None	No	—	3	Edge of septa smooth, without spines.
Diphyphyllum (?) tetrasticum n. sp.	Bushy	\(20–23+20–23\)	?	10–12	Present	1–3	1	\(2/3\)	Semicolon-shaped; the mode of reproduction—as in the genus Rystilus.
Campophyllum (Charactophyllum ?) dimorphictum n. sp.	Solitary	\(30–39+30–39\)	—	25	Present	3–6	?	?	The presence of an internal wall in the juvenile stage, in which the septa reach the center, is a characteristic of septa; short at the adult stage.
Phacellophyllum (Diphyphyllum?) costatum n. sp.	Bushy	\(20+20\)	?	8	Present	1–3	1	0.5	Sharply expressed costae along the entire septa; absence of epitheca, strongly developed inner wall, strongly convex vesicles, and mode of reproduction as in the genus Rystilus—characteristic for this species.
Schluteria rugosa var. westbirica n. v.	Bushy	\(23+23\)	?	9–11	Present?	1–4	1–2–3	0.7	Tabulae are the same as in Schlut. rugosa Wdkd.
Schluteria rugosa var. minor n. var.	Bushy	\(21–22+21–22\)	?	8–10	None	?	1–2	0.4–0.5	Differs from Schl. rug., var. westsib., in the somewhat sharper differentiation of tabulae.
Schluteria rugosa var. major n. var.	Bushy	\(21–27+21–27\)	?	5–14	Weakly developed	1–5	?	0.5	This form differs from the larger development of vesicles and the flattened central part of the tabulae.
Schluteria naibikini n. sp.	Solitary	\(26+26\)	—	21–25	?	?	?	0.6	This species differs in its thick epitheca.
Grypophyllum cylindricum n. sp.	Bushy	\(34–26?\) or \(60+60?\)	—	30–34	None	?	?	?	The characteristic bushy form of the colony.
Cystiphyllum (?) spectosum n. sp.	Solitary	\((68?)\) \(28+28\)	—	20–21	None	?	10–20	?	Without septa; there is an endotheca of vesicles or scattered septa, which pass into septa. The development of the inner wall is characteristic.
Dialithophyllum astalicum n. sp.	Solitary	\(36–37\)	—	21–23	Weakly developed	10–22	?	—	The septa end in the center.
Cystiphyllum macrocyssotum n. sp.	Solitary	—	—	18–19	None	—	—	—	Characteristic are relatively large vesicles.

Name of species	Colony form	\(D\)	\(N_1\)	\(d\)	Pores \(n_1\)	Pores \(n_3\)	Squamae	Spines	\(r\)	Notes
II. Tabulata.
Favosites helderbergiae var. mesodevonica n. var.	Massive	\(>200\)	55	1,7	1	0,9–1	No	No	0,75	Along the edges of the tabulae there are pits.
Emmonsia (Favosites) sibirica n. sp.	Massive	60	110–120	1,5(0,1–1,85)	1	0,9–1	In 1 or 2 rows	Present	0,4–0,5	The characteristic conical form of the corallum and thickening of the walls.
Pachypora cervicornis var. major n. var.	Branching	25–28	24–30	1,7–2,7	1	1,2–2	No	Well developed	0,5–1	Noticeably internal porous canals of the ribs.
Pachypora dubia var. minima n. var.	Branching	4–5	88–100	0,75–1,5 (1,2)	1	?	No	No	?
Pachypora alveolitiformis n. sp.	Branching	25–30	?		1	0,8–1	No	Present	0,5–0,6	Pores—in the form of tortuous porous canals.
Alveolites arbusculus n. sp.	Branching	25–45	400	0,5–0,6	1	0,6–0,85	No	Well developed	0,4–0,6
Natalophyllum giveti n. sp.	Branching	13–26	380–530?	0,3–0,9	1	0,5–0,65	No	?	0,5–0,7
Natalophyllum tubiferum n. sp.	Branching	10–20	270–440	0,25–0,5	1?	0,5–0,75	No	Present	0–9	This species differs by its axial tube with tabulae.
Natalophyllum giveti var. elegantula	Branching	16–25	350	0,2–0,75	1?	0,6–0,8	No	Present	?
Coenites fascicularis n. sp.	Branching	7,5–9	350	0,05–0,6	?	0,7–1	No	Present	0,05–2,0
Neoroemeria vesstibulrica n. sp.	Branching	25–35	35–23	1,7–1,5	1–2	0,7–0,8	No	Present	0,2–0,3	\(\frac{2d}{5}\) in the central zone—1,8–2,2 mm.
N. vesst. v. cylindrica	Branching	40–48	35–56	2,2		0,5–1,5	No	Present	0,2	Cylindrical form of the branch—characteristic.
Neoroemeria (?) parasitica n. sp.	Parasitic	—	45	0,9–1		0,6	No	Present	0,05–0,6	This species differs by a strongly developed structure of the wall, by septal ridges between corallites.
Chonostegites parasiticus n. sp.	Parasitic	—	?	1–1,3			No	Present	0,1–0,4
Monticulipora (?) concentrica n. sp.	Massive colony	\(>55\)	1080–1840	0,15–0,45	—	—	—	Present	0,25	For this species the characteristic features are concentric layers, in some of which the walls are filled with a dark cement.

Species names	Form of the coenosteum	\(D\)	\(n_5\)	\(n_6\)	Astrorhizae	tabulae	Notes
III. Stromatoporoidea. Stromatopora korowini n. sp.	Massive coenosteum	?	0.05—0.6	?	Present	Present	This species is characterized by a dimorphism of the internal structure: layers with the structure of Stromatopora Beuthii Barg. alternate with layers with the usual structure of a stromatopore.
Stromatopora stylophora n. sp.							This species differs from S. korowini n. sp. by the presence of peculiar vertical columns with a dark axial line, as in Str. Beuthii Barg.
Stromatopora (?) parasitica n. sp.	Parasitic coenosteum		0.05—0.5	?	?	Present	This species is distinguished by the development, in some places, of cyst-like tissue of irregular structure, without columns, which are present in other places.
Syringostroma obrutschewi n. sp.	Massive, flat	>150	0.05—0.4 (0.17)	\(\sim 270\)	Present	Present	This species resembles Syr. strahlenbergi Yav., but the latter differs in the somewhat distorted absence of astrorhizal canals.
Parallelopora (?) minuta n. sp.	Massive coenosteum	16—18	0.03—0.15	?	Present	Present	Very strong development of skeletal substance and the presence of cylindrical tubes (600 per 1 cm\(^2\) of tangential section) are a characteristic feature of this species.

In the above table the following designations have been used:

\(N\)—number of septa of the first and second order,
\(D\)—diameter of the colony, or of the corallum,
\(d\)—diameter of corallites or zooids,
\(n_1\)—number of dissepiments crossing the radius,
\(n_2\)—number of rows of dissepiments,
\(n_3\)—distance between septa of any order,
\(n_4\)—number of rows of pores on a face,
\(n_5\)—distance between concentric plates,
\(n_6\)—number of columns per 1 cm\(^2\) of tangential section,
\(r\)—distance between tabulae,
\(N_1\)—number of corallites per 1 cm\(^2\) of tangential section.

All dimensions are given in millimeters.

The latter suggests that this genus, which in other places extends into the Frasnian stage, disappeared in Western Siberia somewhat earlier. This, apparently, is not explained by the facies character of the deposits, since it has not yet been found in any facies of \(D_3\) in Western Siberia. At the same time, this genus is well known in the upper part of the Middle Devonian both along the southeastern margin of the Kuzbass and along the northern one. Thus, for example, I found it in the limestones of the Shcherbak River, to the north-northwest of the village of Lebedyanskoye, in the mass of massive limestones underlying the Lebedyanskoye beds. In this way, this fact confirms the stratigraphic position of the latter in the upper parts of \(D_2\).

Among the positive data indicating the same thing, it is necessary first of all to note the presence in the Lebedyanskoye fauna of the genera Neoroemeria and Chonostegites. Although the genus Neoroemeria has only just been established, nevertheless its derivation from the genus Roemeria gives a very substantial indication of the age of the fauna of the village of Lebedyanskoye, especially if one takes into account that the genus Roemeria, according to my observations and collections, is known in the Kuznetsk Basin so far only in beds no older than \(D_1^2\). The genus Chonostegites was found by me in the vicinity of the village of Bachat, on the southeastern margin of the Kuznetsk Basin—namely in \(D_2^2\), in beds lying considerably above the calceola beds (with Calceola sandalina sandalina). Likewise in the Altai (the Chui steppe) I found it in the upper horizons of the Middle Devonian. Its presence in the Lebedyanskoye fauna, consequently, is an additional fact in favor of their Givetian age.

Further, the species Aulocystis cornigera of Roemer was described by him from the same stage, while Fav. hamiltoniae Hall is widely distributed in the Hamilton formation, which is of equivalent age.

As for the Rugosa, here we can first of all note how far the development of the group Cyathophyllum hexagonum has advanced, represented by forms strongly differing from their ancestors in the Eifelian stage of the southeastern margin of the Kuznetsk Basin¹. Then the presence of the genus Acervularia and of the genus Phillipsastrea, especially characteristic of \(D_3\) and \(D_2^2\), also accords with the assignment of the Lebedyanskoye Devonian to the Givetian stage.

The remarks given above provide a quite clear answer to the question of the age of the coral fauna of the village of Lebedyanskoye. It can only be Givetian, and, apparently, it is closer to the Upper Devonian than to the Eifelian fauna.

There are only two forms that seem to indicate a more ancient age: these are Cystiphyllum senecaënse (?) Bill., distributed in the corniferous limestone (\(D_1^2\)) of Canada, and Amplexus altaicus var. minor nov. var., close to Amplexus altaicus Dyb. The latter, according to Penecke, enters the Eifelian stage, being characteristic of \(D_1^2\). Especially interesting is the presence of the first species, which was found precisely in the lower parts of the Lebedyanskoye Devonian.

Thus, in the Lebedyanskoye Devonian, the upper parts of the Eifelian stage may also possibly be present. However, this question can be resolved definitively only by collecting and studying the fauna specifically from the above-mentioned lower horizons of the Lebedyanskoye Devonian.

To resolve the question of whether our coral fauna belongs to one province or another, we have insufficient data, in view of the fact that the majority of species are peculiar; and, perhaps, it would be advisable to speak of a special West Siberian province.

The representatives of the American provinces are apparently 2 species of Favosites (Emmonsia), as well as several species of Pachypora, whose distinctive features include the presence of squamae. Squamae are characteristic precisely of American species, although, perhaps, this is also explained in part by the fact that European species have been little studied in this respect.

The only undoubted European representative is the species Aulocystis¹ cornigera Schlüter. In general, however, European representatives in the Lebedyanskoye fauna are rather difficult to recognize, and it is characteristic that, despite the brilliant and detailed study of the corals of the Middle Devonian of Germany carried out by Wedekind, we cannot find a significant number of common forms.

All this emphasizes the peculiarity of the Lebedyanskoye fauna, which is striking and is expressed in the presence of 32 new species and varieties established to date².

The most frequent forms in the Lebedyanskoye fauna, and at the same time those having rock-forming significance, are the pachyporids, Alveolites, then corals of the Cyathophyllum hexagonum and C. coespitosum groups, as well as Spongophyllum. In the horizon with Cystiphyllum senecaënse (?) Bill. massive favositids with large colonies predominate.

Rare forms are: Aulocystis cornigera, the genus Natalophyllum, Chonostegites, Aulophyllum, the Stromatopora korovini group and stromatoporoids in general, especially branching ones, Monticulipora concentrica, Aulopora, and some solitary corals, including Amplexus. The rest are fairly common.

In conclusion I would like to dwell on several points that indicate the practical significance of the work carried out. This significance is determined above all by those stratigraphic data that were set forth in the preceding chapters. But this does not exhaust the assistance that the present work can render specifically in the study of the NW part of the Kuznetsk Basin.

Indeed, 10 years have already passed since Prof. M. A. Usov established the overthrust character of the NW boundary of the Kuznetsk Basin. And, as a kind of anniversary gift after the decade since this discovery, we see a brilliant confirmation of his diagnosis, namely, in the reconnaissance work carried out in the area of the village of Lebedyanskoye. By this reconnaissance work a sharp bending of the W. boundary of the Kuznetsk Basin was established, which can be explained only by its overthrust character.

Thus, in connection with this fully proven character of the NW boundary of the Kuznetsk Basin, the task naturally arises of studying the complex structure west of the thrust front.

The solution of such a task encounters serious difficulties. Indeed, west of the Yaya, and still more west of the Siberian railway main line, the area adjoining the Kuznetsk Basin on the W. is covered with taiga and is almost completely devoid of Paleozoic outcrops, since the base level of erosion there lies above the Paleozoic surface. From my personal experience of work in 1929 I know that along a route 10–20 km long one often does not encounter even a single pebble there.

It is here that the significance of this work, as well as of any similar work, will become apparent; thanks to them the smallest remains of fauna found in workings will make it possible to determine the age and thereby—

save them from being fruitless. Moreover, careful examination of alluvium and talus in a number of cases makes it possible to find and then identify fossils with the aid of this and analogous works. In this way considerable funds will be saved on carrying out unnecessary excavations—funds which, of course, exceed many times over the cost of the present work.

It is further necessary to emphasize the great importance, in studying the stratigraphy and tectonics of the margins of the Kuznetsk Basin, of resolving in each exposure the question of whether the beds are overturned or normally deposited. Such a question is easily resolved precisely by studying the position of corals, since from the point or surface of attachment they grow upward and to the sides, and not downward, in the direction of the sea floor. In the case of massive stromatoporoids this is more difficult to decide, and here the non-specialist will be helped especially by the description of the structure set forth above.

Thus, we see that a careful study of Coelenterata can render substantial assistance, and in some cases also save resources, in the study of the stratigraphy and tectonics of the Kuznetsk Basin. Therefore, it seems to me that the execution of the present work corresponds to the stated aim, directed toward the study of the stratigraphy of the Kuznetsk Basin, and that it represents a certain step forward toward the solution of this grand task.

VI. LIST OF LITERATURE CITED

1. Bargatzky, Aug.—Die Stromatoporen des rheinischen Devon. 1881.
2. Billings.—Geology of Canada. Vol. II; p. 1. Geol. Surv. Can.
3. Milne-Edwards et Haime.—Monographie des polypiers fossiles des terrains palaeozoiques. 1851.
4. Frech, F.—Die Cyathophylliden und Zaphrentiden des deutschen Mitteldevon. Palaeont. Abhandl., Bd. III, Heft 3. 1886.
5. Girty, G. H.—A Revision of the Sponges and Coelenterates of the Lower Helderberg Group of New-York. 1894.
6. Gürich.—Palaeozoicum des Polnischen Mittelgebirges. Zap. Miner. Ob-va. II ser. Part 32. 1896.
7. Hall.—Illustration Devon Fossils. 1876.
8. Lambe. A Revision of the genera and species of Canadian palaeozoic corals. Contributions to Canadian Palaeontology. Vol. IV, part. II. Ottawa. 1901.
9. Lebedev, N.—The role of corals in the Devonian deposits of Russia. Transactions of the Geological Committee. Vol. XVII, No. 2. 1902.
10. Loewe, St.—Die devonischen korallen von Ellesmereland. Rep. of the Second Norwegian Arctic Expedition in the “Fram”. 1898–1902. No. 30. 1914.
11. Mac Coy.—British palaeozoic fossils. 1855.
12. Nicholson, H. All.—On the Structure and Affinities of the “Tabulate corals” of the palaeozoic Period. 1879.
13. Nicholson, H. All.—A monograph of the British Stromatoporoids. Palaeontographical Society. 1886–1892.
14. Petts, G. G.—Materials toward the knowledge of the fauna of the Devonian deposits of the margins of the Kuznetsk basin. Transactions of the Geological Section of the Cabinet, Vol. IV, p. 231. 1901.
15. Pocta, Ph.—Bryozoaires, Hydrosoaires et partie des Anthozoaires. Système silurien du centre de la Bohême. Vol. VIII, T. I, 1894.
16. Pocta, Ph.—Anthozoaires et Alcyonaires. Système silurien du centre de la Bohême. Vol. VIII. T. II. 1902.
17. Quenstedt.—Petrefactenkunde Deutschland. v. VI. 1878.
18. Rominger.—Foss. Corals. Geol. Surv. Michigan. 1876.
19. Schlüter, Cl.—Ueber einige Anthozoen der Devon. 1881.
20. Schlüter, Cl.—Corallen des rhein. Mittel-Devon. Abhandlungen d. geolog. Landesanstalt; Bd. VIII. Heft 4. 1885.
21. Simpson, G.—Preliminary descriptions of new genera of palaeozoic rugose corals.
22. Wedekind, Rud.—Das Mitteldevon der Eifel. II Teil. Materialen zur Kenntnis des mittleren Mitteldevon. Schriften d. Gesell. z. Beförderung d. ges. Naturwiss. zu Marburg. Bd. 14. H. 4. 1925.
23. Wedekind, Rud.—Zur Kenntnis der Stringophyllen des oberen Mitteldevon. Sitzungsberichte der Gesellschaft zur Beförderung der gesamten Naturwiss. zu Marburg. No. 1. 1921.
24. Yavorskii, V. I.—Some Devonian Stromatoporoidea from the margins of the Kuznetsk basin, the Urals, and other localities. Izvestiya of the All-Union Geological Prospecting Association. 1931, issue 94.
25. Yavorskii, V. I.—Actinostromidae from Devonian deposits of the margins of the Kuznetsk basin and the Urals. Izv. Gl. Geol.-Razv. Upr., 1930, XLIX, No. 4, pp. 473–496.

EXPLANATION OF THE PLATES

Plate I.

Fig. 1. Amplexus altaicus var. minor n. var. Longitudinal section in natural size.

Fig. 2. Stromatopora korovini n. sp. Radial section in natural size.

Fig. 3. The same. Tangential section × 2.7.

Fig. 4. Stromatoporella sp. Radial thin section in natural size.

Fig. 5 and 6. Stromatopora stylophora n. sp. Tangential and radial sections in natural size.

Fig. 7. Grypophyllum cylindricum n. sp. Transverse section of the corallite × 1.75.

Fig. 8. Parallelopora (Stachyodes?) sp. Transverse section in natural size.

Fig. 9 and 10. Parallelopora (?) minuta n. sp. Radial and tangential sections of the coenosteum in natural size.

Fig. 11 and 13. Campophyllum (Charactophyllum?) dimorphicum n. sp. Two transverse thin sections in natural size.

Fig. 12 and 14. Cyathophyllum (?) sp. Two transverse sections in natural size.

Fig. 15 and 22. Cystiphyllum senecaënse (?) Bill. Transverse and longitudinal sections in natural size.

Fig. 16 and 17. Dialithophyllum asiaticum n. sp. Transverse and longitudinal sections in natural size.

Fig. 18 and 19. Spinophyllum sp. Transverse section in natural size.

Fig. 20. Phacellophyllum (Diphyphyllum?) costatum n. sp. Transverse section of corallite in natural size.

Fig. 21. Cyathophyllum (?) sp. Transverse section in natural size.

Fig. 23. Schlüteria naliokini n. sp. Longitudinal section in natural size.

Fig. 24. Schlüteria rugosa var. major n. var. Transverse section in natural size.

Fig. 25. Acervularia davidsoni (?) Edwards et Haime. Tangential section in natural size.

Fig. 26. Aulophyllum (Duncania?) sp. Transverse section × 4.1.

Plate II.

Fig. 1 and 2. Emmonsia (Favosites) sibirica n. sp. Longitudinal section of coral in natural size.

Fig. 3. The same. Transverse section in natural size.

Fig. 4 and 5. Emmonsia (Favosites) hamiltoniae Hall. Tangential and radial sections in natural size.

Fig. 6 and 7. Pachypora alveolitiformis n. sp. Radial and transverse sections of a twig in natural size.

Fig. 8. Aulophyllum (Duncania?) sp. Transverse section in natural size.

Fig. 9 and 10. Natalophyllum giveticum n. sp. Radial and transverse sections in natural size.

Fig. 11 and 12. Natalophyllum tubiferum n. sp. Transverse and longitudinal sections of a twig in natural size.

Fig. 13. Natalophyllum giveticum var. elegantula n. var. Transverse section in natural size.

Fig. 14. Neoroemeria westsibirica var. cylindrica n. var. Transverse section in natural size.

Fig. 15 and 16. Chonostegites parasiticus n. sp. Vertical section in natural size.

Fig. 17. Neoroemeria westsibirica n. sp. Vertical section in natural size.

Fig. 18. The same as in Fig. 14, × 2.6.

Fig. 19 and 20. Alveolites arbusculus n. sp. Transverse and longitudinal sections of a twig in natural size.

Fig. 21. Natalophyllum giveticum var. elegantula n. var. Longitudinal section of a twig in natural size.

Fig. 22. Pachypora cervicornis de (?) Blainv. Transverse section of a twig in natural size.

Plate III.

Fig. 1 and 2. Syringostroma obrutschewi n. sp. Tangential and radial sections in natural size.

Fig. 3. Stromatoporella sp. Radial section in natural size.

Fig. 4. Stromatopora (?) parasitica n. sp. and Pachypora cervicornis var. major n. var. in natural size.

Fig. 5. Schlüteria naliwkini n. sp. Transverse section of the corallite × 1.7.

Fig. 6. Cystiphyllum macrocystosum n. sp. Transverse section of the corallite × 1.7.

Fig. 7 and 8. Coenites fascicularis n. sp. Transverse and longitudinal sections of a twig in natural size.

Fig. 9. Phacellophyllum (Diphyphyllum?) costatum n. sp. Longitudinal section of the corallite in natural size.

Fig. 11. Syringostroma obrutschewi n. sp. Radial section of the coenosteum × 10.

Fig. 12. Neoroemeria (?) parasitica n. sp. Tangential section in natural size.

Fig. 13. Neoroemeria sp. Transverse section in natural size.

Fig. 14. Pachypora cervicornis (?) de Blainv. Longitudinal section of a twig in natural size.

Fig. 15. The same as in Fig. 4, in radial section, in natural size.

Fig. 16. Stromatopora korovini n. sp. Tangential section × 2.37.

Fig. 17. Emmonsia (Favosites) sibirica n. sp. Tangential section × 2.6.

Fig. 18. Neoroemeria (?) parasitica n. sp. and Syringostroma geba var. Radial section, natural size.

Fig. 19. Aulocystis (?) cornigera Schlüt. Longitudinal section of a corallite × 2.

Plate IV

Fig. 1. Stromatopora korovini n. sp. Radial section of the coenosteum × 10.

Fig. 2. Stromatopora stylophora n. sp. Radial section of the coenosteum × 10.

Fig. 3. Neospongophyllum sp. Transverse section of the corallite × 3.

Fig. 4. Monticulipora (?) concentrica n. sp. Tangential section of the zoarium × 3.

Fig. 5. Monticulipora (?) concentrica n. sp. Radial section of the zoarium × 3.

Plate V

Fig. 1. Neoroemeria (?) parasitica n. sp. and Syringostroma geba var. Radial section × 3.

Fig. 2. Stromatopora stylophora n. sp. Tangential section of the coenosteum × 10.

Fig. 3. Natalophyllum tubiferum n. sp. Longitudinal section of the twig × 3.

Fig. 4. Parallelopora (Stachyodes?) sp. Transverse section of the coenosteum × 10.

Fig. 5. Natalophyllum giveticum n. sp. Transverse section of the twig × 3.

Fig. 6. Natalophyllum giveticum var. elegantula n. var. Longitudinal section of the twig × 3.

Fig. 1.

Lebedyansky Devonian along the Alchedat River. I—bedding, II—reverse faults and thrusts, a—limestone quarry, b—limestone with algae, c—outcrop with rubbed-in coal soot, d—non-overturned beds, e—Yavorovsky’s prospect pits, f—the Balakhon Formation, and g—overturned beds. Meridian—true.

Fig. 2.

Table 1.

Plate 1.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

Plate II.

Plate II.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22

1. This genus is not known in America. ↩↩↩↩↩↩↩↩↩↩↩↩↩↩

2. A characteristic feature of the Lebedyanskoye fauna is the presence of the genus Natalophyllum and of frequently occurring branching Alveolites. ↩↩↩↩

3. At the moment of formation of the connecting plates. ↩↩