ANCULOSA. 



389 



Brot, List, p. 20. Haldeman, Mo log. Le tox -, p. 4, t, i, f. 102-9. Adajis, 

 Genera, i, p. 307. 



Variety b. 



AnculoUts nigrescens, CONRAD, New Fresh-Water S'lells, p. 64, t. 8, f. 17, 1834. 



DeKay, Moll. N. Y., p. 103. Wheatlev, Cat. Shells U. S., p. 28. Jay, Cat. 



4th edit., p. 276. MOllek, Synopsis, p. 30, 1836. 

 Leptoxis nigrescens, Conrad, Binney', Check List, No. 372. Adams, Genera, i, 



p. 307. 

 Anculotus trivittatus, DeKay', Moll., N. Y., p. 102, t. 7, f. 137, 1843. 

 Leptoxis trivittata, DeKay, Binney, Check List, No. 390. Adams, Genera, i, p. 307. 



Variety c. 



Anculotus monodontoides, Conrad, New Fresh-Water Shells, p. 61, t. 8, f. 16, 1834. 



DeKay, Moll. N. Y., p. 102. Jay, Cat., 4th edit., p. 270. Wiieatley, Cat. Shells 



U. S., p. 28. Reeve, Monog. Anc, t. 5, f. 37. Muller, Synopsis, p. 41, 1836. 

 Mudalia monodontoides, Conrad, Chenu, Manuel, i, f. 2046-8. 

 Leptoxis monodontoides, Conrad, Haldeman, Monog. Leptoxis, p. 5, t. 4, .5, f. 124- 



133. Binney, Check List, No. 370. 

 Nitocris monodontoides Conrad, Adams, Genera, i, p. 308. 

 Anculotus dentatus, Codthuoy', Am. Journ. Sci., xxxvi, p. 390, July, 1839. Bost. 



Journ. Nat. Hist, ii, p. 185, t. 4, f. 7, Feb., 1839. Reeve, Monog. Anc. t. 5, f. 36. 



DeK.\Y', Moll. N. Y., p. 102. Jay, Cat., 3d edit., p. 63. 

 Anculosa dentata, Couthuoy, Wheatley, Cat. Shells U. S., p. 28. 

 Leptoxis dentata, Couthuoy, Binney, Check List, No. 352. 

 Nitocris dentata. Couth., Adams, Genera, i, p. 308. 

 Anculosa dentata, LEA, Philos. Proc.ii, p. 34, Apr. 1841. 

 Leptoxis dentata, Lea, Binney, Check List, No. 3.53. 

 Anculosa (Mudalia) ajjinis, Haldeman, Monog. Limniades, Cover of No. 3, March 



13, 1841. 

 Anculotus afflnis, Haldeman, Reeve, Monog. Anculotus, t. 6, f. 53. 

 Leptoxis affinis, Haldeman, Binney, Check List, No. 337. Brox, List, p. 23. 

 Xilocris carinata, Lea, Adams, Genera, i, p. 308. 



Description. — Shell conic, dark horn-color or blackish ; whorls 

 about three, with obsolete, distant wrinkles, and au abrupt, acute 

 prominent, carinated line, which revolves on pj„ ^^g -p. „,„ p. „„„ 

 the middle of the bodj'-whorl, and is con- 

 cealed on the spire by the suture ; suture not iB>^ 

 indented ; aperture oval, half as long as the 

 shell, within sanguineous beneath the carina, 



Fig.j39. Fig. 740. and at base and apex; columella emarginated, a little 

 flattened at the base. 

 Length, about two-fifths of an inch. 

 Variety A. Carina obsolete on the ventral portion 

 of the body-whorl. 



Variety B. Carina distinct on the spiral whorls 

 owing to their more oblique revolution. 

 Ohsermtions.— Thc surface of the whorls of this species is gen- 

 erally covered with unequal calcareous matter, reseml)ling a fortu- 

 itous accumulatiou of mud or earth on that part, but which appears 



