. Bulletin of the Buffalo Society of Natural Sciences. Natural history -- New York (State); Natural history. Fig. 194. Platyceras erection (after Hall). Platyceras erectum. Hall. () (,Vol. Pt. p. 5, PI. II.) Distinguishing Characters.—Closely in rolled apex, for one and one-half volutions; rapidly expanding lower portion; outer surface regularly arcuate to the inrolled spire; concentric laniellose striae, arched abruptly over nar- row bands, marking former sinuosities in the peristome. Found in the Demissa beds, at Section 5 (where small individuals, probably of this speci
. Bulletin of the Buffalo Society of Natural Sciences. Natural history -- New York (State); Natural history. Fig. 194. Platyceras erection (after Hall). Platyceras erectum. Hall. () (,Vol. Pt. p. 5, PI. II.) Distinguishing Characters.—Closely in rolled apex, for one and one-half volutions; rapidly expanding lower portion; outer surface regularly arcuate to the inrolled spire; concentric laniellose striae, arched abruptly over nar- row bands, marking former sinuosities in the peristome. Found in the Demissa beds, at Section 5 (where small individuals, probably of this species, are com- mon). Platyceras carinatum. Hall. (Fig. 195.) (Pal. N. Vol. V., Pt. II., p. 5, PI. II.) Distinguishing Characters.— Oblique, sub-conical or sub- pyramidal form; minute one or one and one-half volutions; rapid expansion below; strong cari- nation on outside of body-whorl, with commonly a depression on either side; obscure plications; oblique aperture; sinuous peristome; undu- lating concentric striae. Found in the Encrinal limestone, and in the Demissa bed, at Section 5 (rather rare); also, rarely, in the middle Trilobite bed. Platyceras thetis. Hall. (Fig. 196.) (Pal. X. Y., Vol. Pt. II., p. 8, PI. III.) Distinguishing Characters. —Arcuate outer surface; closely inrolled apex, making one volution; gradually ex- panding lower portion; nearly round aperture; sinuous peristome; lateral tSclSwffii).1" longitudinal folds; closely arranged lamellose concentric striae. Found in the Demissa bed. at Section 5; and in the middle Pleurodictyum bed, in Avery's Fig. 195. Platyceras cari- inttum (after Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Buffalo Society of Natural Sciences. Buffalo, N. Y. : The Society
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