[2% THE CHICAGO ACADEMY OF SCIENCES. 



1870.— Dall, Alaska Moll., p. 08, fig. 40, 190",.— Baker, Trans. Acad. Sci. St. 

 Louis, XVI, p. 12, 1900. 



Linuuca emarginota Lewi*, Proc. Bost. Soc. N. H., V, p. 124, 1855. — Bin- 

 ney, L. & F.-W. Sh. N. A., II, p. 52, fig. 70, 1805.— Walker, Journ. Conch., II, 

 p. 330, 1879 (part).— Ottawa Nat., I, p. 58, 1882 (part).— Latchford, Amer. Nat., 

 Will, p. 1052, 1884 (part).— Ottawa Nat., II, p. 204, 1885 (part).— Beau- 

 CHAMP, L. & F.-W. Sh. N. Y., p. 3, 1880.— Ottawa Nat, IV, p. 55, 1890 (part).— 

 WALKER, Nautilus, VI, p. 34, 1892 (part).— Taylor, Ottawa Nat., VI, p. 35, 

 1892 (part).— Marshall, Rep. N. Y. State Mus., XLVII, p. 05, 1893; N. Y. 

 WorlcTs Col. Exp., p. 510, 1894.— Walker, Rev. Moll. Mich., p. 17, 1894 (part). — 

 Taylor, Ottawa Nat, VIII, p. 147, 1895 (part). — Maury, Chautauqua Lake 

 Shells, p. 20, fig. 2, 1898.— Baker, Nautilus, XIII, p. 58, 1899.— Baker, Bull. Chi. 

 Acad. Sci., II, p. 193, pi. 1, figs. A, E, 1900.— Walker & Lane, Geol. Surv. Mich., 

 VII, pt. 2, p. 251, 1900. — Stearns, Proc. Nat. Mus., XXIV, p. 291, 1901 (part). — 

 Letson, Bull. N. Y. State Mus., LXXXVIII, p. 54, 1905 (part). 



Limnophysa cmarginata Lewis, Bull. Buffalo Soc. N. Sci., II, p. 135, 1874. 



Radix ampla Lewis, Bull. But Soc. X. Sci., II, p. 135, 1874. 



Limncca ampla Aldrich, Rep. N. Y. St?.te Cab. N. H., XXII, pp. 19, 23, 

 1808. 1 — Beauchamp, L. & F.-W. Sh. N. Y., p. 9, 1880.— Mitchell, Nautilus, 

 XIII, p. 89, 1899.— Marshall, Rep. N. Y. State Mus., XLVIII, p. 043, 1895.— 

 Letson, Bull. N. Y. State Mus., LXXXVIII, p. 52, 1905. 



Limncea barbadensis Sowerby, Conch. Icon., XVIII, Limn. sp. 100, pi. 14, 

 fig. 100, 1872.— Cr. & Fisch., Mis. Cient Alex., II, p. 47, 1880— Pilsbry, Nauti- 

 lus, XXIII, p. 120, 1910. 



Limnceus barbadensis (Beck) Clessin, Conch. Cab. p. 379, tat 50, fig. 2, 

 1880. 



Shell : Elongated to ovate, varying from thin to rather thick ; 

 periostracum very light horn, sometimes darker, pellucid; nuclear 

 whorls small, smooth, rounded, consisting of V/2 white or horn colored 

 whorls in outline similar to those of catascopium; surface and sculp- 

 ture as in emarginata; whorls 5y 2 to 6, rounded, convex, the body 

 whorl quite convex; spire typically long, attenuated, but shorter and 

 depressed in some individuals ; sutures well impressed ; aperture long- 

 ovate, occupying from half to three-fourths the length of the shell, 

 much expanded and flaring in some forms ; interior of the aperture 

 varying from white to brownish ; peristome thickened by a white 

 varix ; inner lip wide, raised, reflected over the umbilical region either 

 entirely closing the perforation or leaving a small chink ; the parietal 

 callus is usually rather thick and sometimes becomes heavy and raised 

 so as to render the aperture continuous ; the umbilical chink is emar- 

 gined as in the typical form ; in some specimens the columella has a 

 heavy, ascending plait; axis twisted. 



1 This record has not been verified. It may have been based on speci- 

 mens of catascopium. 



