|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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Scans and Webpage
©George Langford III, 2011
|TAENIOPHYLLEAE||SIGILLARIA||Sigillaria rhontboidea||SIGILLARIA STELLATA|
|TAENIOPHYLLUM||LEIODERMARIAE||Sigillaria Sculpta||SIGILLARIA SCHIMPERI|
|TAENIOPHYLLUM DECURRENS||SIGILLARIA MONOSTIGMA||SIGILLARIA SPINULOSA||SIGILLARIA CORRUGATA|
|TAENIOPHYLLUM CONTEXTUM||Asolanus Camptotoenia||SIGILLARIA DILATATA||SIGILLARIA LEIODERMA|
|TAENIOPHYLLUM DEFLEXUM||SIGILLARIA FISSA||SIGILLARIA RETICULATA||SIGILLARIA LEPIDODENDRIFOLIA|
|SIGILLARIAE||SIGILLARIA OBLIQUA||SIGILLARIA LORENZII|
Proc. Am. Phil. Soc. (1878), p. 330.
Stems large, leaves crowded, fistular, flat by compression, thick, exactly linear, decurring at the base, surface smooth, opaque or shining.
The plants referred to this division resemble those of the narrow-leaved Cordaites by the size of their leaves only. These are still narrower, more exactly linear, and their surface is not striate or marked by nerves, neither when corticated nor when deprived of their coaly epidermis. Seen with a strong glass, the epidermis appears lined lengthwise and crosswise by a very thin areolation composed of appressed square meshes resembling those of the finest tissue. The leaves, as far as they can be seen, are very long. I have not been able to find one in its entire length in any of the specimens examined. Their points of attachment still more than their smooth surface separates them from Cordaites, these points being marked by linear narrow scars, rounded and slightly inflated at the lower end, generally acute or acuminate upwards. The species referred to this group represent evidently a different generic division, if not a separate family.
The above description, taken from the Proc., l.c., is exact as far as the characters of the generic division could be recognized from the specimens bearing leaves only, which I had then for examination. But recently Mr. I. F. Mansfield, to whom the American coal flora owes already the discovery of specimens of some of its most interesting types, has sent me a large piece of slate seventy centimeters long, covered with remains of Taeniophyllum decurrens, which forcibly eliminates the supposed relation of these plants to the Cordaites.
The specimen represents a trunk of Stemmatopteris Schimperi, covered with a coating of rootlets. To its borders are superposed, in close appressed confused masses, bundles of leaves of Taeniophyllum decurrens, diverging from it under an acute angle of 20-30°, exactly like those in Atlas Plate LXXXI, f. 1, right side. These leaves are remarkably similar to the radicles covering the stems of Stemmatopteris, a little broader, however, apparently tubulose, or hollow cylinders flattened by compression, with a parietal tissue nearly half a millimeter thick. The hollow or inside canal of these leaves, as seen at divers parts where the parietal surface is open, is filled with closely appressed macrospores about one millimeter in diameter (flattened), distributed here and there in patches of various length. Some are seen continuous, five to six centimeters long, four to five millimeters broad, evidently enclosed into these hollow, fistular, leaf-like sporangiophores. As these groups of spores are distributed upon the whole surface of the specimen, and seen at divers places where the cortical tissue is destroyed, there can be no doubt about their relation to the leaves and their mode of attachment to them. But the connection of these bundles of filaments to the trunk of Stemmatopteris is not clear. Towards the lower part the decurring leaves cover the border of the trunk as if they were appressed upon it, and, therefore, possibly coming in contact by casual superposition. But towards the upper part, where the radicles covering the bark of Stemmatopteris are transformed into a thick layer of coal, this layer passes a little out of the borders of the trunks upon the base of the leaves of Taeniophyllum, as if these were derived from the same stem, though none of them are placed in the same direction as the radicles, and none appear mixed with them. There are evidently two kinds of vegetables. The question is only on the connection of the plants, either as casual by the deposits of a tuft of leaves of Taeniophyllum, upon the Stemmatopteris, or in a community of vegetation by parasitic association of this Taeniophyllum. The upper part of the trunk of this Stemmatopteris is free, without connection with any leaves of Taeniophyllum. On the first description of this plant, which was communicated to European Phytopaleontologists, Schimper, Grand'Eury, and other authors have remarked upon the doubtful reference of these vegetable remains to Cordaites. No suggestion has been made upon their relation to any other group of the Carboniferous plants. The character of the fructifications refer them to the Licopodiaceae.
The affinity to living species of this family is, however, not distinctly marked. They may be compared to some Selaginellae; Isoetes, for example. In this genus the spores are axillary, placed in membranaceous sporocarps at the base of the leaves. The sporocarps ascend higher in the leaves than the spores, sometimes to half their length. In these carboniferous plants, the membranaceous spore-cases seem to have been distributed high up into the leaves, or in their whole length, bearing spores either continuous or in successive groups.
The axis of the Isoeteae is short. What I have described as the stems of Taeniophyllum, as seen upon the specimen figured, may represent a prolongation of an axis of the same kind, a stump like that of Plate LXXXIV.
The three species described under this generic name are closely related by the characters of their leaves. Taenophyllum contextum seems a mere variety of Taenophyllum decurens and Taenophyllum deflexum, with its large flat ribbon-like leaves, may perhaps represent the sterile plants of the same species. The reticulation of the thin epidermis is in all of the same character.
TAENIOPHYLLUM DECURRENS, Lesqx, Plate LXXX, Fig. 4; Plate LXXXI, Fig. 1.Characters of the species, same as for the genus.
Lesqx., Proc. Am. Phil. Soc. (1878), p. 331, Pl. LI, f. 4; LII, f. 1.*
Both the figures represent the leaves decurring upon the stem by an elongated base, but in P1ate LXXX the leaves preserve in their length as far at least as it can be seen the same diameter all along their decurring base, while in Plate LXXXI they are gradually narrowed downward to their points of attachment, forming, as appressed upon another or against each other, narrow basilar prominent ridges. The leaves also of Plate LXXX are slightly broader and more distinctly enlarged upwards. As the trunk of this specimen is not seen, I could not compare the point of attachment; and the characters of texture, facies and size of the leaves being the same, I consider them as variable forms of the same species. Perhaps even the variation is caused by a difference in the compression and maceration of fragments of a same plant. The crowded leaves average five to seven millimeters in width, forming by their imbricating and decurring long base a thick coating of coaly bark, which, when destroyed, leaves the surface of the stem smooth, or irregularly lined and wrinkled. It is marked by numerous leaf scars, some of them distinctly seen, others destroyed or obscure, so that their relative position is not definitely recognizable. The scars are placed in spiral order, but their place is not always indicated by the points of attachment. They are generally obtuse and inflated at the base, where they measure one millimeter in diameter only, gradually effaced and narrowed upwards, and therefore their characters are far different from those left by the leaves of Cordaites. The bark of the stem also is much thicker, not merely a thin smooth pellicle of coal, but a coating of shaly carbonaceous matter one millimeter thick or more.
Habitat—Cannelton, Penn'a; Mr. I. F. Mansfield.
TAENIOPHYLLUM CONTEXTUM, Lesqx., Plate LXXXII, Figs. 2, 2a.Leaves narrow, linear, two millimeters broad, apparently very long, obtuse, twisted or interlaced together in tufts and erect, diverging and curved in the upper part.
Lesqx., Proc. Am. Phil. Soc., l.c., p. 332, Pl. LIII, f. 2, 2a.
This species merely differs from the former by the narrower leaves, more distinctly linear, compactly twined in the lower part. They are less flattened, evidently fistulose. Their substance is thick, the epidermis is a coaly layer irregularly disrupted in minute elongated granules, as in Atlas, f. 2a. I have not seen any of these leaves in connection with a stem.
By compression and flattening, an inflated border is here and there formed along some of the leaves, and by their superposition the upper ones seem to have a midrib. In a few cases when the heavy coating of coaly matter is removed the thread-like vessels of the surface appear spread in loose fasciles similar to those of the leaves of Dicranophyllum.
Habitat—With the former.
TAENIOPHYLLUM DEFLEXUM, Lesqx., Plate LXXXIII, Fig. 4.Stem or branch narrow; leaves closely imbricated, apparently decurrent, their base being covered by fragments of broken leaves decurring to and expanding in right angle from the stem; surface smooth.
Lesqx., Proc. Am. Phil. Soc., l.c., p. 331, Pl. LIV, f. 4.
The part of a branch figured here is entirely covered with broken fragments of detached leaves, and its surface is nowhere exposed; the leaves deflexed along the borders in right angle to the stem, seemingly from above the decurring base, are all flattened and parallel, their borders generally contiguous. They measure one centimeter in width and thirty-seven centimeters in length to the point where the specimen is broken. The coaly epidermis is. on the surface, very thin and fragmentary, or spread here and there like powder by decomposition; but the leaves taken altogether appear of a somewhat thick consistence. I have of this species only one specimen, a large piece of shale of which a fragment only is figured. Seen with a very strong glass, the veins of the surface may be approximately counted at twenty in one millimeter space; the cross wrinkles are also of the same size. The tissue of the epidermis is the same as in the former species, merely a little looser. The cross section of the leaves shows both surfaces separated by a thin layer of shale or clay, as if the leaves had been in their original state inflated or tubulose.
Habitat—With the former.
Trunks simple or forking near the apex, smooth, or longitudinally furrowed, marked by leaf scars of various forms, disposed in spiral order; leaves grass-like, triplicate, simple nerved; radicular appendages (Stigmaria) thick, dichotomous, horizontally expanded, bearing long linear simple cylindrical fistulose or flattened leaves or rootlets, more or less regularly disposed in spiral order, leaving as their scars circular mamillae, with a central vascular round point.
The internal structure of the plants of this family is little known as yet, and there is still a degree of uncertainty in regard to their general characters, and to the relation which they indicate to plants of the present time. Brongniart, from the microscopical analysis of the structure of Sigillaria elegans, was disposed to consider the Sigillarie as Gymnosperms, related to Cycadeae. This opinion is admitted by Dawson and Grand'Eury; but the generality of authors refer this family to the Lycopodiaceae. Binney, from a remarkably careful and precise examination of the internal structure of Sigillaria, Quat. Journ. Geol. Soc., May, 1862, Pl. IV, V; Phil. Trans., 1865, p. 580, Pl. XXXI-XXXV, exposes the result of his researches in the following conclusion (p. 591): "Everything led me to believe that the leaves, branches, and probably the fructifications of Sigillaria will prove to be very analogous to those of Lepidodendron." Goldenberg, in Fl. Sarraep., liv. 1 and 2, refers Sigillaria, with Stigmaria, etc., to the Selagineae. He represents, in Pl. A, the characters of the living plants of this family, and in Pl. B, comparative figures of those of the fossil Selagineae, including the fructifications of Sigillaria in strobiles, in close affinity to those of Lepidodendron, only differing by the blades enlarged at the base, without sporanges, but vertically covering agglomerations of macrospores, much like those of Atlas, Plate LXVIII, f 6. It is evident that fructifications of this kind cannot be referred to Gymnospermous plants. From these considerations Heer, Weiss, Schimper, and Stur. admit the Sigillariae into the family of the Lycopodiaceae as a separate group, however.
As American specimens are not in such a state of fossilization that their internal structure can be studied, I consider the question merely from the outside characters of the plants, especially from the scars of their leaves as left upon the bark. In the divisions of the smooth (not furrowed) stems, the scars of some species of Sigillaria are of the Lepidodendroid type, for example, Sigillaria monostigma and Sigillaria fissa, Plate LXXIII, f. 3-6; 17. Not only have these scars a single central vascular scar, without any traces of lateral bundles, but as seen Atlas, f. 6, the subcortical impressions bear caudate appendages like the base of Knorria leaves, or similar to those observed in the subcortical state of Lepidodendron Veltheimianum, etc. The leaves also of Sigillaria, though generally longer than those of Lepidodendron, are of the same character, and cannot be compared to leaves of Cycadeae, or of any other kind of gymnosperms.
As for Stigmaria as roots, the question of its true relation to Sigillaria or Lepidodendron is discussed with the description of the Genus.
Trunks large, simple or
dichotomous near the apex, marked by leaf scars in vertical series,
separated by furrows, or placed in spiral order, either contiguous or
more or less distant, very variable in size and shape, round, oval,
truncate or emarginate, hexagonal, transversely rhomboidal, etc., with
three vascular scars, one simple medial punctiform, the two others
lateral, of semi-lunar or linear shape. Leaves linear, long,
triplicate, carinate or plane, with a distinct medial nerve.|
The leaves are rarely found attached to the stems. Goldenberg, in his monography of the genus Sigillaria, disposes the species in four different groups, according to the general disposition and shape of the leaf scars: Leiodermariae, Clathrariae, Rhytidolepis, and Syringodendron. These subdivisions are followed and defined here for the description of the American species.
|§ 1. LEIODERMARIAE.|
Surface of the trunks not costate; leaf scars more or less distant, not contiguous.
SIGILLARIA MONOSTIGMA, Lesqx., Plate LXXIII, Figs. 3-6.Supercortical leaf scars broadly rhomboidal, constricted and acute at the sides, rounded at the upper and lower part; vascular scars simple, punctiform, in the middle of a smaller central rhomboidal mammilla, or naked, at or near the top of the leaf scars; decorticated surface very variable; impressions of the leaf scars generally large, oval, with a small transversely rhomboidal cicatrice and a vascular point in the middle, or with the cicatrices obsolete, topped by an enlarged vascular mamilla with an inflated linear protuberance like the inflated base of the leaves of a Knorria; surface between the scars always more or less distinctly and regularly striate in opposite directions, obliquely to the scars.
Geol. Rept. of Ill., II, p. 449, Pl. XLII, f. 1-5; IV, p. 446, Pl. XXVI, f. 5.
Schp. Paleont. Veget., II, p. 101.
Asolanus Camptotoenia, Wood, Proc. Acad. Nat. Sci. Phila., p. 238, Pl. IV, f. 1.
The cortex of this species is easily separated in thin lamellae, and the scars vary in their characters according to the degree of decomposition or decortication of the trunks. I have endeavored to represent the more important of their features, but I must say that among two or three scores of specimens which have been and are still under my examination, I have rarely found two of them exactly similar in all their characters. The leaf scars especially are very variable. Generally the striae of the surface, diverging from the scars in oblique and in opposite direction, are seen upon the successive layers of the bark, even some traces of them are left upon the decorticated surface of Atlas, f. 6.
The subcorticated scars are much longer, oval, with the outlines of Atlas, f. 4, without any rhomboidal scar, merely smooth, flat, or marked by a vascular point near the top. Upon the naked stem they are as nearly linear as in the lower part of Atlas, f. 5.
The distance between the leaf scars vary from eight to twenty millimeters in the spiral direction of the scars, and from center to center. The average size of these scars in their state of preservation or as rhomboidal, is vertically five millimeters, one millimeter more transversely. In the decorticated state the oval scars measure eight to twelve millimeters vertically, and are only half as broad.
Schimper compares this species to Sigillaria rimosa, Gold., which it resembles indeed, as remarked in my first description, by the decorticated oval scars ; but all the essential characters are different. Sigillaria rimosa has the triple vascular scars of a Sigillaria, while Sigillaria monostigma has only a single vascular point, and is by this character a transitional form relating this group of Sigillaria to Lepidodendron. In the European species also the striae or wrinkles are lengthwise as seen upon all the specimens represented by Goldenberg, while in Sigillaria monostigma they diverge in opposite directions from the scars, and this also is seen upon all the corticated or semi-corticated American specimens which I have examined.
I know of no relation to this species which, until now, represents a type peculiar to the American coal flora. With the following it could be separated as a subdivision of the genus.
Habitat—Not rare at Colchester, Ill. Abounds at Cannelton, Penn' a, where Mr. I. F. Mansfield has obtained splendid and very numerous specimens representing the characters of the species in a multiplicity of forms. Found also at Pittston, coal B, by Mr. R. D. Lacoe.
SIGILLARIA FISSA, Lesqx. Plate LXXIII, Fig. 17.Leaf scars distant, umbonate, rhomboidal, deeply emarginate at the upper border, rounded at the lower, angular on the sides; vascular scars marked by a single point near the top of an inside smaller rhomboidal mamilla.
Geol. of Penn'a, (1858), p. 871, Plate XIII, f. 4.
Schp., Paleont. veget., II, p. 100.
This species is represented by a single specimen. It differs from the former by the scars a little more distant, deeply emarginate at the upper border, less enlarged on the sides, with a central convex mamilla, and by the wrinkles or striae of the surface merely undulating lengthwise. Perhaps these characters are not persistent, and therefore should not be considered as specific. They are not remarked, however, upon any of the numerous specimens of the former species.
Sigillaria denudata, Goepp., Perm. fl., p. 200, Pl. XXXIV, f. 1, is closely allied to this species, differing essentially by the triple vascular scars.
Habitat—Muddy creek, near Shamokin, a locality where I found some plants of peculiar types not seen elsewhere, Sigillaria Schimperi, among others.
SIGILLARIA OBLIQUA, Brgt., Plate LXXIII, Fig. 18.Leaf-scars oblique, mammillate, rhomboidal, prolonged and rounded in the lower part, truncate or emarginate at the top, angular on the sides; vascular scars three, the lateral ones long, linear, arched; cortex rugose, ribbed lengthwise.
Brgt., Hist. d. veget. foss., p. 429, Pl. CLVII, f. 1, 2.
Lesqx., Geol. of Penn'a, 1858, p. 871.
Sigillaria rhontboidea, Brgt., ibid., p. 425, Pl. CLVII, f. 4.
Gold., Flor. Sarraep., II, p. 22, Pl. VI, f. 6.
Schp. Paleont. veget., II, p. 99.
Sigillaria Sculpta, Lesqx., Geol. of Penn'a, 1858, p. 871, Plate XIII, f. 3.
The leaf-scars are a little more than one centimeter distant from center to center in the oblique direction of. the spiral, six to seven millimeters long and as broad between the lateral angles, rounded at the lower border and distinctly emarginate at the apex, (in the American specimens). Sigillaria obliqua, as figured by Brongniart and Goldenberg, has the scars obtuse, both at the upper and lower borders. It is on account of this difference that I did separate the American form as Sigillaria sculpta. Possibly, however, the disks upon the specimens seen by the European authors may have been somewhat deformed by maceration and compression. For in Brgt. f. 1, l.c., a few of them are slightly emarginate. Hence the essential characters being identical it is advisable to consider the American form as a mere variety. The subcorticated scars have not been seen by European authors. In the form described as Sigillaria sculpta the vascular scars seen under the cortex are double, oval, close, but not contiguous, four to five millimeters long, one to one and a half millimeters broad, twice as long, of the same width and in the same relative position as in Atlas, Plate LXXIII, f. 19a. The surface between them is irregularly and less distinctly wrinkled lengthwise.
Habitat—The species is not rare, and indeed presents different forms at the different localities where it has been found. As Sigillaria sculpta, I found it at the Gate vein of New Philadelphia, an upper coal. A specimen of the same type in the cabinet of Mr. R. D. Lacoe, No. 574, from the Plymouth colliery, represents it upon a surface of about fifty centimeters (square). I have seen it also from Duquoin coal, Ill. As Sigillaria rhomboidea, it is in many specimens from Oliphant, in the cabinet of Mr. R. D. Lacoe.
SIGILLARIA SPINULOSA, Germ.Cortex undulately striate lengthwise, slightly rugose crosswise; scars in quincunxial order, vertically and longitudinally equidistant, trapezoidal, rounded at the lower border, narrowed to a truncate or slightly emarginate top; laterally angular in the middle; vascular scars three, the middle transversely linear or punctiform, the lateral linear, obliquely diverging; tubercles scattered in the intervals, small, centrally deeply concave.
Verst., p. 58, Pl. XXV.
Gold., Flor. Sarraep., II, p. 20, Pl. X, f. 5.
Schp., Paleont. veget., II, p. 102, Pl. LXVII, f. 12.
The only difference to note in the characters of the species, as indicated by the specimens I have for examination, is the smaller size of the disks. They measure seven to eight millimeters transversely and five millimeters vertically, while in the European form they average about two millimeters more in both directions. The distance from center to center in horizontal and vertical lines is two centimeters. The small tubercles scattered upon the bark in the intervals between the disks are rare, nearly immersed in the wrinkles, one and a half millimeters in diameter, apparently scars of adventive rootlets, as supposed by Schimper, rather than remains of the base of spines, as supposed by Germar. The wrinkles of the surface are not as large as in the former species and not smooth, but rugose crosswise; the leaf scars are narrower at the top, more broadly rounded at the base. I can see no other difference between this species and the former.
Habitat—This form is extremely rare in the American coal measures; I found the specimen described above, in a bed of sandstone shale, at Massillon, Ohio, and I have not seen any other. It is Si. 22b of the collection of the Museum of Comp. Zool., Cambridge, Mass.
SIGILLARIA DILATATA, Lesqx.Leaf-scars close and small; flat or slightly umbonate, enlarged and acuminate on the sides, the upper border emarginate, the lower arched; cortex minutely undulately striate lengthwise.
Geol. of Penn'a, 1858, p. 871, Plate XIII, f. 5.
Schp., Paleont. veget., II, p. 101.
This species is quite distinct and easily recognized. The scars, six millimeters distant in their spiral direction, are vertically three millimeters in diameter only and twice as broad, being compressed and acuminate on the sides. The medial vascular scar is comparatively large, the lateral ones mostly joined and covering it. The decorticated surface is also rugose lengthwise, marked with thin undulating lines, and the vascular scars three, the two lateral oval, less than one millimeter long and half as broad, the medial one punctiform.
Habitat—Carbondale. First seen in the collection of Mr. Clarkson. Found later near Port Carbon and at Muddy Creek. Specimens Si. 17, 54, of the Museum of Comp. Zool., Cambridge.
SIGILLARIA RETICULATA, Lesqx., Plate LXXIII, Figs. 19, 19a.Leaf-scars large, close, transversely rhomboidal, obcordate or emarginate at the upper border, enlarged and acuminate on the sides, rounded at the base; surface obscurely and irregularly costate lengthwise, transversely rugose.
Geol. Rept. of Ark., II, p. 310, Pl. III, f. 2.
Schp., Paleont. veget., II, p. 99.
The leaf-scars have about the same shape as in the former species, but are much larger, five millimeters high, eight millimeters broad, less dilated on the borders; the surface is distinctly transversely wrinkled, except around the somewhat umbonate scars, where it is smooth and also sometimes marked lengthwise by irregular large striae, as in the specimen figured in the Ark. Geol. Rept., l.c. The decorticated surface has the vascular scars like those of the former species, comparatively larger.
Habitat —Male's coal bank, Ark. Sent also from the coal fields of Alabama, by Mr. T. H. Aldrich. As yet this species is subconglomerate.
Cortex distinctly undulately wrinkled lengthwise; leaf-scars in quicunxial order, vertically less distant than horizontally, transversely oval, narrowed, but obtuse on the sides; vascular scars in the middle.
The species is closely allied to the former, differing by the form of the scars, oval, equally arched on the upper and lower border, contracted but somewhat obtuse on the sides, eight millimeters broad, and half as high. The decorticated scars are not exposed. The cortex is deeply undulately striate between the scars, which are one centimeter distant in horizontal direction, but slightly lineate in the space only half a centimeter wide, which separates them vertically.
Habitat—Seen in the cabinet of Mr. Wm. Lorenz, of Philadelphia, from Raush Gap, Mammoth vein, Penn'a.
SIGILLARIA STELLATA, Lesqx., Plate LXXIII, Fig. 20.Leaf-scars in quincunxial position, plane, large, broadly rhomboidal-hexagonal, emarginate at the top, hall round at the base, angular on the sides; cortex distinctly wrinkled in undulating striae diverging star-like from the scars; vascular scars three, the lateral oval, the middle punctiform.
Geol. of Penn'a, 1858, p. 871, Plate XIV, f. 2.
Schp., Paleont. veget., II, p. 101.
Species allied to Sigillaria reticulata, but widely different by the shape of the leaf-scars and the peculiar direction of the striae of the surface. The scars, as broad as long, are eight millimeters in diameter, flat and smooth. The lateral vascular impressions are oval, as in the decorticated surface of the species of this group, with an arched line under them. The vertical distance between the scars is fifteen millimeters, the horizontal twenty-three.
Habitat—Seen in the cabinet of Mr. Clarkson, in splendid specimens obtained at Carbondale. The Museum of Comp. Zool., Cambridge, has one (Si. 2) from the same locality.
SIGILLARIA SCHIMPERI, Lesqx., Plate LXXIII, Fig. 21.Surface transversely and vertically rugulose, horizontally thinly striate; leaf-scars large, nearly round in outline; upper marginal line deep, extending horizontally on. the sides; the lower less distinct; vascular scars two, oval, obliquely diverging, with an arched linear impression above them.
Geol. of Penn'a, 1858, p. 871, Plate XIV, f. 1.
Schp., Paleont. veget., II, p. 101.
The figure is not exactly copied, in this only, that it does not well represent the rugosity of the surface thinly transversely striate by disconnected narrow lines traversing even the leaf-scars, and then rugulose obliquely between the scars which appear thus as placed into lozenge-shaped latticed frames. The leaf-scars, one and a half centimeters broad, one centimeter in vertical direction, are formed of an upper border marked by a deep broad highly convex line curved horizontally on the sides, with lower concave borders closing the circle under and near the vascular impressions.
The characters of this species are somewhat abnormal, especially in the absence of a medial vascular point, which is not remarked upon the specimen. The epidermis of the leaf-scars has been, however, partly destroyed, the scars being flat, not mammillate as they are generally in the species of this group.
Habitat—Found in the shale of an old mine of Muddy Creek. The specimen is large, S. 1, Museum of Comp. Zool., Cambridge.
SIGILLARIA CORRUGATA, Lesqx.Cortex deeply rugose lengthwise; leaf-scars large and distant, oval in outline, tumescent in the middle, with a round small mantilla and two oval lateral impressions under it.
Geol. Rept. of Ill., IV, p. 445, Pl. XXIV, f. 4; XXV, f. 5, decorticated.
This species has the facies of a Lepidodendron. The oval scars one centimeter long, seven millimeters broad, surrounded by a flat border one to two millimeters broad, are gibbous in the middle and there marked by a round vascular scar, placed between and above two lateral oval ones, which resemble the appendages of a Lepidodendron.
These scars are extremely variable, and when deformed by abrasion of one or two of the upper cortical layers, they generally preserve, as outlines of their essential characters, a large round vascular scar in the middle of an oblong impression, acuminate at both ends.
Habitat—Marseilles, Lasalle county, Ill. Specimens in a poor state of preservation.
SIGILLARIA LEIODERMA, Brgt.Cortex smooth, disks oval, not angular, marked in the center by a small horse-shoe-shaped or oval vascular scar.
Hist. d. veg. foss., p. 422, Pl. CLVII, f. 3.
Schp., Paleont., veget., II, p. 98.
I refer to this species two specimens with ovate leaf-scars or disks ten to fifteen centimeters long, four to seven millimeters broad in the middle, rounded at the lower border, obtuse and narrower at the top. One of them bears a single central oval scar or mamilla; the other is marked with a horse-shoe-shaped line under the vascular point. The disks are a little less obtuse at the top than in Brongniart's figure. The cortex in one of the specimens is very thinly lineate lengthwise; in the other it is slightly granulose.
The species of Brongniart is probably made from a specimen in a better state of preservation than those which I had for examination and which have the surface more or less obliterated. This may account for the difference in the characters.
The leaf-scars of this species, are much like those of the former. It, therefore, merely differs by the nearly smooth surface of the trunks. The reverse of one of the specimens, evidently decorticated, has large disks joined vertically by a tumescent prolongation of the base.
Habitat—One of the specimens with smaller disks is (Si. 24) in the collection of the Museum of Comp. Zool. of Cambridge, from Massillon, Ohio. The other is in the cabinet of Lafayette College, Easton, Pa., from Port Carbon, Pa.
SIGILLARIA LEPIDODENDRIFOLIA, Brgt.Cortex irregularly striate, grooved lengthwise, but without ribs, transversely wrinkled under the areoles ; leaf-scars rhomboidal-ovate, angular on the sides; upper and lower borders rounded; vascular scars three.
Hist. d. veg. foss., p. 426, Pl. CLXI.
Gold., Fl. Sarraep., II, p. 21, Pl. VI, f. 10, 11.
Lesqx., Geol. of Penn'a, 1858, p. 871.
Schp., Paleont. veget., II, p. 100.
One of the specimens of this species, seen at Summit Lehigh in a private collection, represents it with the characters described by the author. The other has the leaf-scars irregularly disposed, as in Brongniart's figures, also of the same shape, but a little smaller. The scars deformed by compression are more generally oval, but those in a good state of preservation have the same form as in the European specimens, or like f. 3, Brgt., l.c., with smaller leaf-scars. These, though varying from seven to twelve millimeters long, have the same transversal diameter, seven millimeters.
Habitat—Specimen Si. 105; of the Museum of Comp. Zool. of Cambridge, is the one with smaller leaf scars, which I refer to this species. It is from the roof shale of Morris, Ill. The other specimen, from Summit Lehigh, was not obtainable. The species, very rare in the American coal measures, appears common in Europe, as besides the references quoted above, it is described also, without figures, by Heer and Grand'Eury.