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. 1845 Excerpt: ...shells do not agree perfectly with Say's description, copied above; yet they most probably constitute the species he had in view. They differ from P. trivolvis by having a much more oblique peritreme, the whirls more nearly cylindrical, the diameter increasing less rapidly, and without any tendency to carination upon ...
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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. 1845 Excerpt: ...shells do not agree perfectly with Say's description, copied above; yet they most probably constitute the species he had in view. They differ from P. trivolvis by having a much more oblique peritreme, the whirls more nearly cylindrical, the diameter increasing less rapidly, and without any tendency to carination upon the left side. PLANORBIS TRIVOLVIS, Say. Plate 2.--Figs. 4--7. P. testa utrinque excavata, ad simstram subcarinata, anfractibus 4 subcylindraceis: pagina dextra in medio umbilicata. SYNONYMS AND REFERENCES. Lister. Conch, tab. 140, fig. 46. P. TrivoLvis, Say. Nich Encyc, art. Conchology, pl. 2, fig. 2.--Am. Conchology, pl. 54, fig. 2.--Bulla fluviatilis, (non Turt., ) Journ. Acad., ii. p. 31. (Junior.) P. Corpulentus, Say. Whittemore. Am. Journ.Sci., vol. 38, p. 193. P. Regularis, Lea. Proc. Am. P. S., vol. 2, p. 32. DESCRIPTION. Animal "dark russet or dusky, covered with pale yellowish dots."--Gould. Shell flattened laterally, having four subcylindrical whirls, which are finely striated across by the lines of growth: left side slightly carinated, the carina being most apparent upon the inner whirls: spire slightly impressed, and (within the last whirl) nearly level: there are two and a half whirls visible upon the right side, the antepenultimate disappearing within the umbilical cavity: aperture large, vaulted anteriorly and slightly thickened within the margin; its faces project considerably beyond the planes of the shell. Color rufous, or yellowish-brown. Geographical Distribution. Occurs in New England, New York, Lake Erie, the Delaware and Schuylkill, and in the Northwest Territory. Dr. Richardson found it from Lake Superior to Saskatchewan. OBSERVATIONS. The peritreme is not as oblique as in P. glabratus, and both sides of the ap...
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Add this copy of A Monograph of the Freshwater Univalve Mollusca of the to cart. $63.74, good condition, Sold by Bonita rated 4.0 out of 5 stars, ships from Newport Coast, CA, UNITED STATES, published 2016 by Wentworth Press.
