184 THE CHICAGO ACADEMY OF SCIENCES. 
Bulimnea differs generically from the rest of the family in its 
peculiar bulimiform, darkly colored shell, its long, club-shaped penis, 
and large and irregular prostate. The penis is very peculiar, being 
very long, and gradually increasing in diameter to the end, which is 
cut off almost squarely and not rounded as in other Lymnzas; the 
end is more than double the diameter of the organ as it leaves the 
penis-sac; the protractor muscles of the penis-sac are also more nu- 
merous than in any groups excepting Lymnea. 
Bulimnea megasoma (Say). Plate XXV, figures 1-6. 
Lymneus megasomus SAy, Rep. Long’s Exp., Il, p. 263, pl. 15, fig. 10, 
1824; Binney, reprint, p. 129, 1858. 
Limneus megasomus KUster, Conch. Cab., ed. ii, p. 36, taf. 6, figs. 20, 21, 
1862. 
Limnea megasoma HALDEMAN, Mon. Limn., p. 13, pl. 3, figs. 1-3, 1841.— 
DeKay, Zool. N. Y., p. 70, pl. 4, fig. 70, 1843——-LApHAM, Trans. Wis. St. Agr. 
Soc., II, p. 368, 1852.—KirTLAnp, Trans. Clev. Acad. Nat. Sci., II, p. 6, 1854.— 
BEAUCHAMP, L. and F. W. Sh. N. Y., p. 9, 1886. 
Limnea megasoma C. B. Apams, Amer. Journ. Sci., XL, p. 267, 1841.— 
Bett, Can. Nat. and Geol., IV, p. 213, 1859—C. B. Apams, Thomp. Hist. Vt., 
p. 153, 1842 (mec. fig.) ; pamphlet, p. 3—Strmpson, Sh. N. Eng., p. 52, 1851.— 
BrnNEy, Check List, p. 12, 1860—LAPHAM, Proc. Phil. Acad., p. 155, 1860.— 
Bett, Can. Nat. and Geol., VI, p. 43, 1861—WHuttTEAvEs, Can. Nat. and Geol., 
VIII, p. 102, 1863.—Binney, L. and F. W. Sh. N. A,, II, p. 37, fig. 46, 1865.— 
CurRIER, Kent. Sci. Inst., Mis. Pub., No. 1, 1868.—GouLp, Binney’s ed., p. 470, 
fig. 722, 1870.—BLAND and Binney, Amer. Journ. Conch., VII, p. 162, 1871.— 
Tryon, Con. Hald. Mon., p. 94 (68), 1872—SmitH, Rep. U. S. Fish Com., p. 
701, 1874—WaALkeER, Journ. Conch., II, p. 330, 1879.—Cr. and Fiscu., Moll. Mex., 
II, p. 41, 1880—Hyatt, Amer. Nat., XIV, p. 51, 1880.—Datt, Bull. Phil. Soc. 
Wash., III, p. 75, 1881; Smith. Mis. Coll., XX, p. 75, 1881—Trans. Ottawa 
Nat. Field Club, I, p. 58, 1882; I, p. 74, 1883—-FiscHER, Man. Conch., p. 506, 
1883—Tryon, S. and S. Conch., III, p. 101, pl. 103, fig. 5, 1884—Standard 
Nat. Hist., I, p. 308, fig. 356, 1884—Curisty, Journ. Conch., IV, p. 346, 1885.— 
Trans. Ottawa Nat. Field Club, II, p. 351, 1886—-SHrmeEK, Bull. Lab. Nat. 
Hist., Univ. Iowa, I, p. 68, 1888.—Ottawa Nat. IV, p. 56, 1890—WAtLKER, Nau- 
tilus, VI, p. 32, 1892——Taytor, Ottawa Nat., VI, p. 35, 1892—MarsuHatt, Rep. 
N. Y. State Mus., XLVIII, p. 63, 1893.—LatcHForD, Ottawa Nat., VII, p. 115, 
1893.—WaLKER, Rev. Moll. Fauna Mich., p. 17, 1894——MarsHALL, Rep. N. Y. 
at World’s Fair, p. 510, 1894.—SarcEnT, Nautilus IX, p. 127, 1896—HANHAM, 
Nautilus, XIII, p. 5, 1899——Baxker, Shells of Land and Water, pl. and fig. p. 
18, 1903.—WuiTEAVEs, Rep. Geol. Surv. Canada, p. 163A, 1905.—LeEtson, Bull. 
N. Y. State Mus., LXXXVIII, p. 52, 1905—CHapwick, Nautilus XX, p. 22, 
1906; Bull. Wis. Nat. Hist. Soc., N. S., IV, p. 81, 1906.—BaAker, Science, N. S., 
XXVII, p. 943, 1908—Apams, Rep. Geol. Surv. Mich., 1908, p. 20, 1909. 
Limnea megastoma REEVE, Elements of Conch., p. 79, 1860.—Sowersy, 
Conch. Icon., XVIII, Limn., sp., 11, pl. 2, fig. 121, 1872. (Error in plate, note, 
pl. 2, fig. 12, not fig. 11.) 
