. Catalogues of the Silurian fossils of the island of Anticosti, with descriptions of some new genera and species. Paleontology; Paleontology. Fig. 25. Fig. 26. Fig. 25.— Oncoceras Teucer. Fig. 26.— " Pettiti, A small specimen. 0. Teucer, n. sp.—Shell much constricted near the aperture ; strongly tumid on the ventral side ; gently concave on the dorsal aspect; becom- ing more slender towards the apex. Section with the dorso-ventral diameter a little less than the lateral. Length of the specimen following the outer curve 23 lines ; in a straight line 20 lines ; transverse width in the con-
. Catalogues of the Silurian fossils of the island of Anticosti, with descriptions of some new genera and species. Paleontology; Paleontology. Fig. 25. Fig. 26. Fig. 25.— Oncoceras Teucer. Fig. 26.— " Pettiti, A small specimen. 0. Teucer, n. sp.—Shell much constricted near the aperture ; strongly tumid on the ventral side ; gently concave on the dorsal aspect; becom- ing more slender towards the apex. Section with the dorso-ventral diameter a little less than the lateral. Length of the specimen following the outer curve 23 lines ; in a straight line 20 lines ; transverse width in the con- striction near the aperture 7 lines ; at the most ventricose part, appar- ently at the third septum 8 lines; dorso-ventral diameter at the constric- tion 6J lines ; at the third septum 8 lines ; depth of chamber of habitation about 4 lines. The three last septa appear to be about 1 line distant from each other in the middle of the ventral side, but as they are obscurely seen, further proof is required. Siphuncle unknown. Surface with obscure engirdling striae or minute folds of growth. Township of Grimsby : Nia- gara formation. J. Pettit. 0. Pettiti, n. sp.—This species attains a length of four or five inches, and is somewhat variable in shape, the smaller individuals being more rounded in the section, and slightly more curved in the apical half. They all have the form peculiar to the genus,—constricted at the aperture, gra- dually enlarging for one-third or one-half the length, and then tapering. 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 Geological Survey of Canada; Billings, E. (Elkanah), 1820-1876. Montreal, Dawson brothers; London, New York [etc. ] Baillière
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Keywords: ., bookaut, bookcentury1800, bookdecade1860, booksubjectpaleontology
