. Bulletin - New York State Museum. Science. EEEKMANTOWN AND CHAZY FORMATIONS OF CHAMPLAIN BASIN 4II Camcfoceras curvatum sp. nov. Plate 2, figure 6, 7 Description. ]\Iedium sized cyrtoceracones with extremely closely arranged septa and large, marginal siphuncle. The size attained by the mature conch is unknown; the fragment which is the type of the species has a length of 62 mm but its rate of grow^th which is 8 mm in 62 mm (17 mm at smaller diameter and 25 mm at larger diameter) indicates a missing apical portion of 123 mm, and the living chamber is also missing. The type specimen can be sai
. Bulletin - New York State Museum. Science. EEEKMANTOWN AND CHAZY FORMATIONS OF CHAMPLAIN BASIN 4II Camcfoceras curvatum sp. nov. Plate 2, figure 6, 7 Description. ]\Iedium sized cyrtoceracones with extremely closely arranged septa and large, marginal siphuncle. The size attained by the mature conch is unknown; the fragment which is the type of the species has a length of 62 mm but its rate of grow^th which is 8 mm in 62 mm (17 mm at smaller diameter and 25 mm at larger diameter) indicates a missing apical portion of 123 mm, and the living chamber is also missing. The type specimen can be said to have had a length of approximately 200 mm. The curvature is slight (the hight of the arc of the fragment is 3 mm) and a little stronger in the apical than in the anterior part of the conch. The section of the conch is circular. The cameras are exceedingly shallow; there being counted 9 of them in the space of 20 mm in the type specimen. The sutures have been observed only in part and a narrow high saddle on the inner side of the conch has been noticed. The septa are very thin, advancing considerably on the convex side of the phragmocone and their depth is thrice that of the cameras. The shell is thin and not only the siphuncle but also the chambers appear to have become partly filled wdth organic deposit. The siphuncle, which is tubular and exactly two fifths the width of the phragmocone, is in contact wdth the wall at the inner side of the curve Isee text fig. 2]. The endosiphocone „. _ '- . ° •• '- Fig". 2 Cameroceras is verv long and slender (30 mm) and the curvatum sp. nov. .' o y o .1 1 ransverse seen n. x f^ endosiphosheaths are correspondingly long conical in shape. The endosiphotube is well developed. The septal necks end upon the geniculations of the preceding septa.^ Position and locality. In the dove-colored Chazy limestone (C^) of Isle La Motte (loc. 215, Professor Perkin's coll.; type in the collection of Burlington University). Its presence in the
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectscience, bookyear1887
