| SECOND GEOLOGICAL SURVEY OF PENNSYLVANIA - REPORT OF PROGRESS P. DESCRIPTION OF THE COAL FLORA OF PENNSYLVANIA AND OF THE CARBONIFEROUS FORMATION THROUGHOUT THE UNITED STATES BY LEO LESQUEREUX; ©1879 |
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LEPIDODENDRON
Surface
of the stem, marked by peculiar scars, points of attachment of the
leaves; leaf scars (bolsters) rhomboidal-oblong upon the bark of large
trees, or merely rhomboidal upon the small branches, very variable in
size according to their position, enlarging comparatively to the growth
of the stems, often disfigured by dilation of the bark; central
cicatrices (inside scars) rhomboidal, transversely dotted by three
points (vascular scars), bearing generally, under the lower margin, two
oval small tubercles, scars of bundles of vessels (appendages) placed
on each side of a medial line (cauda), which, like the appendages, is
more or less distinct, sometimes deep and wrinkled across, sometimes
obsolete.The characters of the fructifications, the relative position of the leaves, and the mode of division of the stems are those of the Lycopodiaceae. The spikes or cones of the fructifications are described under the generic name of Lepidostrobus, the blades of their sporanges as Lepidophyllum. The species of this genus are difficult to determine, for the specific characters are mostly derived from the scars, left upon the branches at the point of attachment of the deciduous leaves, scars generally observable by counter impressions upon hard materials, shale or sandstone. The leaves were persistent only upon small branches; therefore, the fragments bearing leaves have the scars very small, generally crowded and more or less indistinct, while upon the larger branches or upon trunks, the cicatrices are modified, in size at least, by the age of the trees, or upon their different parts, by casual alterations in the process of their growth. It has been, therefore, often contended that the determination of fragments of Lepidodendron was very unreliable, arid that most of the authors had too widely and without sufficient reason, increased the number of species of this genus.*
I do not wish to enter into a discussion on the matter. All the so-called species established upon specimens of fossil plants are more or less unreliable and subject to criticism. What I have said in regard to the determination of the Ferns is equally applicable to that of the fragments of Lepidodendron, Sigillaria, etc. The variations of the scars, in Lepidodendron at least, is mostly depending from the enlargement of the bolsters by age. They are often crushed and defaced by compression or abrasions, especially towards the base of the trunks, as all the fossil vegetable remains are more or less defaced by maceration, compression, etc. In Sigillaria the scars are generally of a different character, under every successive layer of the bark. In Lepidodendron, the character of the bolsters, preserved against abrasion, are often recognizable upon the whole length of large trunks. **
In any case, I have endeavored to fix the species of this genus from the examination of as large a number of specimens as I was able to obtain for comparison. And I have also taken into consideration the specimens bearing leaves and represented them as often as their characters were clearly defined. The descriptions apply equally to the impressions and the outside surface of the scars. Little is known yet of the internal structure of Lepidodendron. A species, Lepidodendron Harcourti, has been described by Brongniart from microscopical analysis of silicified specimens in comparison with Sigillaria and Stigmaria. Arch. du. Museum, d' Hist. Nat., I, 1839. The characters of this species have an affinity to those of some Lycopods of the present epoch, Psilotum and Tmesipteris. Another species, Lepidodendron vasculare, has the structure of Sigillaria. The roots of these large trees also, are not positively known. Some authors regard the Stigmaria as roots of Sigillaria and Lepidodendron. As the plants of these two families are different in their internal structure and now referred by a number of authors, the ones to Lycopodiaceae, the others to phoenogamous gymnosperms, Stigmaria is not likely to represent the roots of two groups of vegetables widely separated by the structure of their stems. In some localities where remains of Lepidodendron are abundant and where species of this genus constitute the essential compounds of the coal, I have found, in the shale, small sterns of Lepidodendron all of the same size with very short divisions, short leaves and branches crowded upon each others in every direction, seemingly creeping, and thus apparently rhizomas of species of this genus. This however is merely hypothetical; for I have never seen a trunk of Lepidodendron preserved standing with roots attached to it, and no case of that kind has been observed by phytopaleontologists. The leaves of Lepidodendron though variable, especially in length, generally preserve their specific characters. They have a medial nerve, formed of parallel bundles of vessels which, in large leaves, become separated and more or less distant. The leaves therefore appear doubly or triply nerved as in Atlas, Plate LXIII, f. 8. The age of the Lepidodendron coincidates with that of the more productive part of the carboniferous. Few species are recorded from the Devonian; most of them, as also the largest representatives of the genus, are found with the conglomerate measures, at a short distance below and above them. Their remains have been very rarely found at the horizon of the Pittsburgh coal. Goeppert, however, describes three species from the Permian. Among them, remarkably enough, Lepidodendron Veltheimianum, generally considered as a leading plant of the lower or subconglomerate Coal measures. It is however there represented especially by Knorria, eleven species of which are quoted by the author as its synonyms. We have here evidently one of those cases of confusion upon which I have remarked already. Another of these Permian species is Lepidodendron anceps, also a Knorria of uncertain character. The third Lepidodendron, formosum, is, from the characters exposed in the figure of the author, a true Sigillaria. The separation of Lepidodendron into different genera has been attempted by some authors, among others by Sternberg and Goldenberg. The last, in Fl. Sarraep., I, p. 16, fixes the characters of Lepidodendron, Sagenaria, Aspidiaria and Bergeria from the relative position of the bolsters and the mode of attachment of the leaves, either on the top or on the middle of the cicatrices. These characters being unreliable, this classification has not been admitted by any recent Phyto-paleontologist. All the following species are described from American specimens. | ||
| Species known with stems, leaves and fructifications. | ||
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LEPIDODENDRON STERNBERGII, Brgt., Prodr.
Branches long and slender,
flexuous; leaves coriaceous, small, narrowly lanceolate from a slightly
enlarged base, gradually acuminate, half open and more or less incurved
from the middle; medial nerve thick; borders reflexed; bolsters
rhomboidal-oval upon the branches, exactly rhomboidal and equally
narrowed at both ends upon the old stems, with an obscure triangular
protuberance seen at the top upon slender branches; cones small,
cylindrical, obtuse; sporanges short, cuneiform; bracts closely
appressed and imbricate, lanceolate, acute.Lepidodendron lycopodioides, St., Ft. d. Vorw., 1, p. 26, Pl. XVI, f. 1, 2, 4. Lepidodendron gracile, Ll. & Hutt., Foss. fl., I, Pl. IX. Lepidodendron elegans, Ll. & Hutt., ibid., II, Pl. CXVIII. Lepidodendron selaginoides, Ll. & Hutt., I, Pl. XII. The numerous fragments representing this species are all upon the same kind of shale and have been obtained from the same place. Related as they are by their characters, they represent evidently the same species. The branches one millimeter broad, are flattened, comparatively long and sparingly forking; the leaves closely imbricated are only five to seven millimeters long and one millimeter broad, toward the slightly enlarged base. The strobiles are all exactly cylindrical, obtuse, two and a half to four centimeters long, one centimeter in diameter, with bracts of the same length as the leaves but a little broader and lanceolate or gradually narrowed from the base to an acute point. A single one of the strobiles, disconnected from any stem, is much larger, twelve centimeters, two centimeters in diameter, with bracts of the same character as those of the small ones, also exactly cylindrical in shape. It may have been depending from a stronger branch. The bolsters as seen upon older branches or upon trunks, and described above, have the same characters as those of Lepidodendron elegans, Ll. and Hutt., l.c. When covered by the coaly epidermis, which, in large stems, is nearly half a millimeter thick, the bolsters are merely convex without any traces of inside scars, except a round point in the middle, just like those of Lepidodendron Selaginoides, Ll. and Hutt., l.c. When decorticated, the large bolsters twenty-two millimeters long, one millimeter broad, narrowly rhomboidal, have under the apex a small triangular inflation with a more distinct central point or mammilla. By the form and character of the bolsters, this species corresponds with the description of Lepidodendron selaginoides, St., in Schp., Paleont. veget., II, p. 31, while by the characters of the leaves and cones it represents a diminutive form of the species quoted above as synonyms of Lepidodendron Sternbergii. But all the other forms, a large number, among them Lepidodendron dichotomum, which are also referred as synonyms to the same Lepidodendron Sternbergii by Shimper and Geinitz, have their bolsters either square or broadly oval, narrowly acuminate at both ends, clearly marked with an inside transversly rhomboidal scar, already distinct at the base of the leaves of small branches. Hence the American specimens referable by their characters to Lepidodendron Sternbergii, as indicated by the synonymy which I have admitted, positively differ from Lepidodendron dichotomum and other allied forms which I mention with the description of this last species. These specimens which come from the subconglomerate coal, differ somewhat in the size of the branches, leaves and cones, from Lepidodendron Sternbergii as described by St. and Ll. and Hutt. The differences are not wide enough to authorize a specific distinction. Habitat—Black Creek Coal, Ala. Communicated in numerous specimens by Mr. Thos. Sharp, superintendent of the New Castle Coal Co. | ||
| Species known with branches and leaves. | ||
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Branches of medium size, rigid;
leaves open, lanceolate; bolsters, transversely rugose,
rhomboidal-oval, narrowed and acuminate at both ends; inside scars
central, transversely oval, the upper line slightly emarginate in the
middle and mucronate, the lower half round; appendages obsolete. The leaves, half open, sometimes turned down as in the large fragment of f. 2, are one and one half to three centimeters long, largest at the point of attachment, two to four millimeters broad, gradually narrowed to a. sharp acumen, with a thin though distinct medial nerve. Typically allied to Lepidodendron Volkmannianum, St. Habitat—Clinton coal, Mo., Dr. J. H. Britts. | ||
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LEPIDODENDRON LANCEOLATUM, Sp. nov., Plate LXIII, Figs. 3-5a.
Branches of medium size; leaves open or in right angle to the stems, a little curved up toward the apex, lanceolate, acute, slightly broader in the middle; scars narrowly obovate or oblanceolate, open at the base, emarginate and topped with a small round mammilla; surface smooth; cauda deeply marked, not wrinkled. The leaves are short, comparatively to their width, one and one half centimeters long, and nearly three millimeters broad in the middle. The young bolsters, f. 3 and 5, narrowly obovate, are separated by narrow borders which do not connect at the base. The inside scar as seen before its full development is narrowly rhomboidal, the round mammilla at its top indicating its point, when older. The species is related to Lepidodendron marginatum, Presl., differing especially by the inside scar placed lower down on the bolsters. In old specimens, the bolsters become narrower, more elongated, nearly continuous, appearing like ribs of Calamites. Habitat—Clinton Coal, Dr. J. H. Britts. | ||
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Stems of small size; leaves short and narrow, linear, acuminate, open from the base, curved up toward the apex, or in right angle to the stems; medial nerve obsolete; bolsters oval, narrowed and acuminate at both ends; inside scars round, placed near the apex, with a central round point. I should have considered this species the same as the former, but for the short and very narrow leaves, seven to ten millimeters long, scarcely one millimeter broad, nearly linear, more sharply acuminate and without a visible medial nerve. In my specimens, the inside scar is not fully developed; outlined as rhomboidal in shape, it is placed at the top of the bolsters, f. 6b, as in Lepidodendron vestitum, Atlas, Plate LXIV, f. 15, which may represent the same species. I refer to this a small specimen from Cannelton, described in manuscript as Lepidodendron setifolium. It differs only by the quite smooth surface of the bolsters. Habitat—Clinton Coal, Dr. J. H. Britts. | ||
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LEPIDODENDRON LATIFOLIUM, Sp. nov., Plate LXIII, Figs. 7-8.
Fragment of a cylindrical stem
flattened by compression leaves large, three nerved; bolsters exactly
rhomboidal, with equal parallel margined sides; inside scars at the
top, same form as the bolsters; vascular points distinct; appendages
none; cauda marked by wrinkles only.Lepidodendron salebrosum ? Wood, Trans. Amer. Phil. Soc., XIII, p. 345, Pl. VIII, f. 6. This fragment, not an impression, but the cross section of a whole stem, is a very fine one, remarkable by the distinctness of the convex bolsters, the position of the inside scars and the width of the leaves, at least seven millimeters broad, probably very long. They are really three nerved, with an inflation between the border lines. I do not know of any form to which this species may be compared. Lepidodendron salebrosum, Wood, loc. cit., seems to represent it in its decorticated state. Habitat—The specimen was presented to me twenty years ago by Mr. Ed. Jones, supt. of the coal mines at Oliphant, Pa. It comes from that locality but the reference to the horizon of the coal is not indicated. It is in the collection of the Museum of Comp. Zool., Cambridge; Check L. 20. | ||
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Stem large; supercortical bolsters indistinct in outline; inside scars transversely rhomboidal and angular, more enlarged on the sides; vascular scars distinct; sub-cortical bolsters tumescent, rhomboidal, acute on the more enlarged sides, rounded at the top and the base, marked by three large distinct vascular points, without inside scars; leaves long and narrow, three-nerved. The fragment is not easily analysed, on account of its double representation. On the left side, the corticated surface is marked with inside scars bearing leaves; on the right the under surface is seen, with the bolsters upraised, as born upon an inflated base representing apparently, in a different shape, both the bolsters and the inside scars seen upon the bark. The leaves are at least thirty centimeters long, five and half millimeters broad, crowded, forming by compression a thick layer upon the surface. They have the same kind of nervation as those of the former species. a thin medial nerve, with a broad border on each side. Habitat—Shale of the coal of Morris, Ill. Communicated by Mr. Jos. Even. | ||
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LEPIDODENDRON ACULEATUM, Sternb.—Plate LXIV, Fig. 1.
Bolsters large,
rhomboidal-ovate or spindle-shaped, narrowed, elongated and curving at
both ends in opposite direction; inside scars a little above the
middle, rhomboidal-ovate, obtuse at the top, enlarging to the narrowed
and slightly obtuse sides, decurring in an acumen to the cauda, and
small comparatively to the holsters; appendages distinct, cauda
wrinkled across; leaves very long, narrow, in right angle to the stems,
channeled by abroad medial nerve.St., Flor. d. Vorw., 1, p. 23, Pl. VI, f. 2. Lesqx., Geol. of Penn'a, 1858, p. 874. Schp., Paleont. Veget., II, p. 20, Pl. LIX, f. 3; LX, f. 1, 2, 6. Sagenaria aculeata, Presl., in St., Fl. d. Vorw., II, p. 177, Pl. L XVIII, f. 3. Sagenaria caudata, St., ibid., p. 178, Pl. LXVIII, f. 7. Lepidodendron undulatum, St., loc. cit., 1, p. 21, Pl. X, f. 2, (decort.) Aspidiaria undulata, St., ibid., II, p. 182, Pl. L XVIII, f. 13, (decort.) Lepidodendron appendiculatum, St., ibid, 1, p. 38, Pl. XXVIII. Lepidodendron ingens, Wood, Proc. Acad. Nat. Sci., Phil., June, 1860, p. 239, Pl. VI, f.4. Lepidodendron Lesquereuxii, Wood, ibid., p. 240, Pl. V, f. 4. Lepidodendron ureum ? Wood, Trans. Am. Phil. Soc., XIII, p. 343, Pl. IX, f. 5. This species, says Schimper, is generally found with Lepidodendron obovatum. He supposes that it may be a variety of it, merely distinct by its narrower bolsters, more elongated and acuminate at both ends. From the characters of the American specimens, which I consider its representatives, it is evidently different. The inside scars are nearly central, more elongated, narrower, not half round, but only obtuse at the upper border. The leaves are narrow, two and a half millimeters broad, distinctly channeled by the broad nerve, and very long, at least sixteen centimeters, disposed in right angle to the stem. The bolsters, though still bearing leaves, are large, already two centimeters long, eight millimeters broad, and therefore the persistence of the leaves may be considered as a specific character. Habitat—The species is not rare in the anthracite measures of Penn'a. —Minersville, Summit-Lehigh, Carbondale. From the last locality is the specimen L. 99, of the Museum of Comp. Zool. Cambridge, with leaves partly broken. Another, L. 119, is from Newport, Rhode Island, with leaves preserved longer, but nevertheless not in their integrity. A single specimen, L. 118 of the same collection, in nodules from Mazon Creek, and with the surface decorticated, represents Lepidodendron (Sagenaria) caudatum, St. l.c. | ||
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LEPIDODENDRON RIGENS, Lesqx.
Geol. Rept. of Ill., IV, p. 429, Pl. XXVII, f. 1-3. Lepidodendron dichotomum, Roehl, Foss., Paleont., XVIII, p. 125, Pl. XI, f. 2. Top branches with long rigid inflated sub-cylindrical leaves; bolsters upraised, rhomboidal, laterally enlarged; inside scars of the same form, shorter, covering the upper half of the bolsters. The fragment described is from the nodules of Mazon Creek, and has preserved its original characters without any deformation by compression or maceration. It shows the bolsters much inflated, the point and mode of attachment of the leaves around the inside or leaf scar, and the bundles of vessels passing up into the leaves. It also represents the leaves to be half round, even in the upper part, as seen from detached fragments, more than twenty centimeters long, three millimeters in diameter, gradually acuminate, grooved lengthwise by a narrow flat channel tracing the direction of the vessels. Another specimen of the same species has the leaves flattened by maceration, with their epidermis transformed into a thick coating of coaly matter. Channeled on one side, obtusely keeled on the other, the groove is marked on each side by a distinct line, and none is seen in the middle, the medial bundle being immersed into the substance of the leaves. Roehl, l.c., has figured a splendid specimen from a much larger branch than those I had for examination. The upraised scars, the inflated leaves very rigid, all the characters, indeed, are identical with those described above. He refers this branch to Lepidodendron dichotomum, St., which, as it will be seen in the description of this species, has short lanceolate flat leaves, in no way comparable to those of our plant. Habitat—Mazon Creek, in nodules; Mr. S. S. Strong. | ||
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LEPIDODENDRON LONGIFOLIUM, Brgt., Prodr.
Lepidodendron dichotomum, St., Fl. d. Vorw., p. 23, Pl. IIl. Ll. and Hutt., Foss. fl., III, Pl. CLXI. Schp., Paleont. Veget., II, p. 22. Lepidodendron Sternbergii, Ett., Fl. v. Radnitz, p. 54, Pl. XXVI, f. 1, 2. Pl. XXVII and XXVIII. Scars of the branchlets similar to those of Lepidodendron dichotomum; leaves very long and narrow, crowded in tufts at the top of the branches. The specimen shows only the top of a branch, the scars being covered by the leaves are not distinct. Their characters are taken from the description of this species in Schimper, l.c. The leaves are very narrow, scarcely two thirds of a millimeter broad at the base, pressed upon another, crowded in tufts, straight and rigid, twelve to sixteen centimeters long or more, with a deep medial nerve and borders reflexed. Except that the branch is smaller, the specimen is perfectly similar to that represented by Lindley and Hutton, l.c. Sternberg considers the fragment figured in his work, l.c., as a young individual of Lepidodendron dichotomum. The specimen described here is the top of a young branch. In Lepidodendron dichotomum, all the fragments of the same kind bear short leaves. The similarity of the scars upon large trunks merely proves that old scars of Lepidodendron of different species may be alike, and that, therefore, a confusion of species established from the bolsters of this genus is quite as possible or frequent as a specific multiplication caused by variations upon the same stems. Habitat—The specimen is in the cabinet of Mr. R. D Lacoe, of Pittston, Penn'a, from Brown colliery, E vein. It is the only one I have seen of this species in the American coal measures. | ||
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LEPIDODENDRON VELTHEIMIANUM, St., Plate LXII, Figs. 6-8.
St., Fl. d. Vorw., I, p. 12, Pl. LII, f. 3. Roehl, foss. fl., p. 130, Pl. VIII, f. ; Pl. XXIII, f. 5. Lesqx., Geol. Rept. of Ill., II, p. 455. Schp., Paleont. veget., II, p. 29. Stur, Culm. fl., p. 269, Pl. XVIII, f. 2, 3; Pl. XIX, f. 5, 6, 8, 9, 10; Pl. XX, f. 1-6; Pl. XXI; XXII, f. 1-3. Heer, Fl. d. Baren Insel, p. 38, Pl. VIII, f. 1-7 ; Pl. IX, f. 2-4. Lepidodendron giganteum, Lesqx., Boston Journ. S. N. H., v. VI, p. 429; Geol. of Penn'a, 1858, p. 874, Plate XV, f. 2. Lepidodendron Greenii? Lesqx., Geol. Rept. of Ill., IV, p. 433, PI. XXVII, f. 7-8. Lepidodendron mammillatum, Lesqx., ibid., p. 432, Pl. XXV, f. 1. Sagenaria Veltheimiana, Presl., in St., l.c., p. 180, Pl. LX VIII, f. 14. Goepp., Fl. d. Uebergsg, p. 180, Pl. XVII-XX ; XXIII, f. 1-3; XXIV, f. 2, 3; XLIII, f. 1. Koechl., Schlumb, and Schp., Terr. trans. d. Vosges, p. 336, Pl. XXI-XXVI. Sagenaria elliptica, Goepp., l.c., p. 184, Pl. XLIII, f. 7. Sagenaria acuminata, Goepp., ibid., p. 185, Pl. XXIII, f. 4; Pl. XLIII; f. 8-10. Phytholithus cancellatus, Steinhauer, Trans. Am. Phil. soc., p. 280, Pl. VI, f. 2-6.*
Trunk large; leaves linear-lanceolate, small, slightly narrowed near the base, half open; bolsters rhomboidal, oblong or spindle-shaped, acuminate to both ends; inside scars in the middle of the bolsters, transversely rhomboidal, more acute at the sides, highly convex; appendages rarely distinct; cauda deep smooth or wrinkled. The characters of the bolsters and scars of this species are extremely difficult to fix, on account of their great diversity according to the age or the size of the trunks and branches, and to the presence or absence of the cortex and of the epidermis. The above description is made from the representation in Stur., l.c., Pl. XIX, f. 5, 6. I have seen in Mr. D. R. Lacoe's cabinet, a number of finely preserved specimens, which, corticated, have the bolsters in elongated lozenge form, with the prominent inside scar rhomboidal, acute on the sides, the top and base obtuse, distinctly marked near the base by the three vascular points, with a deep furrow, passing from the top of the scar to that of the bolsters and continued downward by a deep, slightly wrinkled cauda. In a decorticated state, this furrow is generally preserved with the central scar either round or rhomboidal, as in Atlas, f. 6. Under different circumstances, the medial scars become oval, surrounded by an oval base, which follows the borders and curve around it or is joined under it, as in Atas, f. 7. This last configuration is however very rare. Heer refers the fragment which represents it under the name of Lepidodendron commutatum, Schp., l.c., p. 39, Pl. VII, f. 8-10, to Ulodendron commutatum, Schp., a species figured Atlas, Plate LXVI, f. 2. I do not consider this reference as right; for in that Ulodendron the oval scars have a central point surrounded by a ring, while in the decorticated young specimens of Lepidodendron Veltheimianum, the oval bolsters are either topped by an upraised rhomboidal acute impression, as in Atlas, f. 7, and also in those figured by Heer, l.c., while in older decorticated stems, when left without top scars, the bolsters are longitudinally traversed by a narrow ridge. I must, however, say that f. 6 and 7 of Atlas, which I described as Lepidodendron Greenii, l.c., and which represent a mere fragment of a large slab, are as yet unique, and cannot be positively compared to any other representative of a Lepidodendron. The reference of the specimen, therefore, to Lepidodendron Veltheimianum, is merely presumable from its likeness to the decorticated bolsters of this species, which are sometimes oval, and from its subconglomerate habitat. In Lepidodendron Veltheimianum, the bolsters are always contiguous before decortication; this character does not agree with the great distance of the scars, as marked, Atlas, f. 7. There is in the cabinet of Princeton college, New Jersey, a specimen which I refer to the same species, and which has the bolsters oval, topped by a small rhomboidal scar bearing a single point in the middle. The bolsters are only one centimeter long, including the leaf scar at the top, four millimeters broad, and two and a half centimeters distant in the oblique direction of the scars. This indicates a greater separation of the bolsters than it is generally observed. This form, like that of Atlas, f. 7, may represent Lepidodendron Wickianum, Heer, l.c., whose scars, though small, are sometimes very distant. Other specimens in the cabinet of Prof. E. B. Andrews bear broadly oval scars, five millimeters long, four broad, convex, marked at the top by a small mammilla, like those mentioned from Princeton. They are more than seven millimeters distant, sometimes irregular in their relative position, as in Lepidodendron Wickianum, but separated by longitudinal wrinkles which mark the outlines of continuous borders of the effaced bolsters. Then, it seems, these specimens may be considered as representing still a variety of this polymorphous species. F. 6, Atlas, is from a specimen of Alabama. It is probable that the branches and leaves described as Lycopodites asterophyllitaefolius, Lesqx., Geol. Rept. of Ill., II, p. 447, Pl. XXXVII, f. 3, are referable to this species. Habitat — Mostly found in the subconglomerate coal measures. The specimen of f. 7 is from Mercer county, subcarboniferous measures of Illinois; common in the Alabama coal field; Helena mines. The specimen, Atlas, f. 6 and a number of others of the same character, are in the cabinet of Mr. R. D. Lacoe, from Campbell's Ledge, subconglomerate, and also from Seneca and Boston vein, Pittston. Those of Prof. E. B. Andrews come from the shaft of Jackson coal, Ohio. Sub- or intra-conglomerate. | ||
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Stems slender, bearing loosely imbricated linear-lanceolate acuminate leaves, with broadly rhomboidal or round mucronate scales intermediate to their point of attachment. The figure represents all what is known of these peculiar vegetable remains, which might possibly be referable to Lycopodites. The scales appear to have covered all the stem, placed like the leaves in spiral order, their base being close to that of the leaves, or even covering it. These scales, as seen, Atlas, f. 3, are somewhat thick, or inflated in the middle to half a milimeter. They are easily detached from the stem, even off from it in many places where their impressions remain distinct. They are two millimeters in diameter, nearly round or broadly rhomboidal, slightly mucronate, as seen, Atlas, f. 3b-3d, marked in the middle by a longitudinal inflated line passing from the sometimes emarginate or mucronate top to the base. No plant from the coal measures has any relation to this. The leaves are much narrower than those of Lepidodendron Veltheimianum. The scars of the leaves are indistinct, as effaced by the superposition of the scales which leave concave impressions of exactly the same shape. Habitat—Helena coal mines; communicated by Prof. Eug. A. Smith. Specimen No. 18 of the State Cabinet of Alabama. | ||
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LEPIDODENDRON PRIMAEVE, H. D. Rogers.
Geol. of Penn'a, 1858, II, p. 828, f. 675. Schp., Paleont. Veget., II, p. 36. Bolsters fusiform, marginate, umbonate, confluent at their ends; leaf scars obsolete. The figure represents a fragment of a dichotomous stem with bolsters, as described above, bearing at the top a fascicle of leaves larger than they are generally seen in this genus, smooth or lineate, without distinct middle nerve. The specimen appear decorticated, and the leaves are obscurely delineated. Habitat—Near Huntingdon, Penn'a, from the Devonian Marcellus epoch. I have found at the same locality a quantity of fragments of Lepidodendron leaves normal in their characters, long, linear, canaliculate and nerved. | ||
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LEPIDODENDRON CORRUGATUM, Davis.
Branches slender; leaves
linear-lanceolate, acuminate; bolsters close, contiguous at base,
laterally more or less distant, ovate, acute at both ends; inside scars
placed above the middle, small, rhomboidal or punctiform. In the
decorticated state the bolsters are grooved convex or carinate in the
middle.Geol. surv. of Canada, 1873, p. 19, Pl. II, III, IV, V, f. 33-36 and 38. Stigmaria minuta, Lesqx., Geol. of Penn'a, 1858, p. 871, Plate XVI, f. 1, 2. Lepidodendron scobiniforme, Meek, Appendix Bull. Phil. Soc., Wash., (1875), p. 13, Pl. I, f. 1. Prof. Dawson gives, l.c., a very detailed account of his species, describing and figuring the very variable characters of the fragments which represent it. The bolsters vary in length from five to twelve millimeters and from two to four in width. Schimper compares to it Lepidodendron Veltheimianum, St. The relation though marked, by the form especially of the decorticated bolsters, is however distant, on account of their comparatively small size and of their small inside scars. The figure of a separate bolster, Pl. II, f. 13a, l.c., is about exactly the same as that of Lepidodendron lanceolatum, Atlas, Plate LXIII, f. 5. Prof. Dawson's species is however distinct by the characters of its leaves, the form and central position of the inside decorticated scars, etc. I refer to this species the fragment f. 2, of the Geol. of Penn'a, l.c., which represents the stem of a Stigmaria constantly found in connection with it. The areoles or bolsters at first round, very small, with a central vascular scar as in Stigmaria, become, upon the stem, oval, narrowed to the base and marked from the top to the middle by a dividing short furrow. It represents f. 15 and 29 of Daws., l.c. I refer also to the same species Lepidodendron scobiniforme, Meek., which has the inside scars at the top of the areoles and these contiguous at the base corresponding to Dawson's f. 27 and 36. The description of Prof. Meek is very clear and refers to the divers forms of this species including Stigmaria minuta, Lesqx. Habitat— Specimens from the Chemung or Hamilton group of Akron, Ohio, are in Prof. Hall's collection, according to Prof. Dawson's remarks. The species is extremely variable and common in the red shale at the base of the Carboniferous of Penn'a, near Pottsville. Also in Virginia, Lewis Tunnel. Prof. F. B. Meek. | ||
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