A Preliminary Catalogue of the Shell-Bearing Marine Mollusks and Brachiopods of the Southeastern Coast of the United States; With Illustrations of Many of the Species (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1889 Excerpt: ...and slopes rapidly to the evenly rounded anterior end; the ventral margin is regularly curved and is rather more convex than in C. glacialis, and shows a very decided emargination at the base of the rostrum; the posterodorsal margin is nearly straight but slopes from the beak to the end of the rostrum which is of moderate length and tapers from the base to the narrow, subtruncated end; it has no distinct diagonal ridge, but is separated from the body of the shell by a strongly marked depression. The surface is nearly smooth but is covered with line lines of growth which are most distinct on the rostrum. The hinge margin is thin. The right valve has a thin, low, much elongated posterior lateral tooth which runs nearly parallel with the dorsal margin, above which it projects in a broad curve; the cartilage-plate is small, very oblique, and closely united with the tooth from which it is separated by a faint, curved notch; no buttress. In the left valve there is no lateral tooth, and the cartilage-plate is very small, slightly prominent, with a curved inner edge. The inner surface of the shell is smooth and the muscular scars are faint. Length of an average specimen, 13 mm.; height, 8 mm.; breadth, 6.5 mm.; beak to end of rostrum, 8.5 mm.; beak to anterior end, G mm. This species is allied to C. glacialia, from which it differs in its more swollen form, more oblique anterior end, more prominent ventral margin, more clearly defined rostrum, and straighter postero-dorsal margin. The hinge shows still more decided differences; the Lateral tooth of the latter is stouter, more prominent, and less prolonged; the cartilageplate is smaller and less distinctly defined. From G.fraterna it differs in being less produced ventrally and in having a longer rostrum with much s...