428 THE CHICAGO ACADEMY OF SCIENCES. 



1870. DALL, Alaska Moll, p. 68, fig. 46, 1905. BAKER, Trans. Acad. Sci. St. 

 Louis, XVI, p. 12, 1906. 



Limnaa emarginata LEWIS, Proc. Bost. Soc. N. H., V, p. 124, 1855. BIN- 

 KEY, L. & F.-W. Sh. N. A., II, p. 52, fig. 76, 1865. WALKER, Journ. Conch., II, 

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

 XVIII, p. 1052, 1884 (part). Ottawa Nat., II, p. 264, 1885 (part). BEAU- 

 CHAMP, L. & F.-W. Sh. N. Y., p. 3, 1886. 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. 65, 1893; N. Y. 

 World's 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. 26, 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 emarginata LEWIS, Bull. Buffalo Soc. N. Sci., II, p. 135, 1874. 



Radix ampla LEWIS, Bull. Buf. Soc. N. Sci., II, p. 135, 1874. 



Limncea ampla ALDRICH, Rep. N. Y. State Cab. N. H., XXII, pp. 19, 23, 

 1868. 1 BEAUCHAMP, L. & F.-W. Sh. N. Y., p. 9, 1886. MITCHELL, Nautilus, 

 XIII, p. 89, 1899. MARSHALL, Rep. N. Y. State Mus., XLVIII, p. 643, 1895. 

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



Limn&a barbadensis SOWERBY, Conch. Icon., XVIII, Limn. sp. 100, pi. 14, 

 fig. 100, 1872. CR. & FISCH., Mis. Cient. Mex., II, p. 47, 1880.^PiLSBRY, Nauti- 

 lus, XXIII, p. 120, 19io. 



Limnaus barbadensis (BECK) CLESSIN, Conch. Cab. p. 379, taf. 50, fig. 2, 

 1886. 



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

 periostracum very light horn, sometimes darker, pellucid; nuclear 

 whorls small, smooth, rounded, consisting of 1^ white or horn colored 

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

 ture as in emarginata; whorls 5^ 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. 



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

 mens of catascopium. 



