LYMNZIDA OF NORTH AMERICA. 163 
Distr1BuTIon: North and middle America. Principally south 
of Canada and east of the great plains. 
The Succinea-like shells of Lymnea columella have been usually 
placed in Radix on account of the large, somewhat flaring aperture. 
Dr. Dall, in his Alaska Mollusca, has expressed the opinion that it 
belongs to Stagnicola. A study of the anatomy shows that it differs 
markedly from Stagnicola in its genitalia and in its radula. The pe- 
culiar shape and small size of the prostate, the number and position 
of the retractor muscles of the male organ and the Succinea-like form 
of the shell have led the author to erect a new genus for the reception 
of these peculiar shells. 
Pseudosuccinea columella (Say). Plate XXIII, figures 8-20; 
plate XXIV, figures 1-4, 
Lymnea columella Say, Journ. Phil. Acad., I, p. 14, 1817.—Ear.e, Report 
on Geol. Zool. Mass., p. 558, 1833.—GouLp, Lamarck’s Genera, pur O9y aiess—— 
RAVENEL, Cat. Sh. Cab. Ravenel, p. 11, 1834—Earte, Geol. Zool. Mass., p. 23, 
1835.—Htcu., Geol. Zool. Mass., p. 27, 1835——Goutp, Rep. Geol. State Maine, 
I, p. 119, 1887.—Lea, Trans. Amer. Phil. Soc., IX, pp. 11, 12, 1841.—Lins.ey, 
Amer. Journ. Sci., XLVIII, p. 282, 1845—Wueattey, Cat. U. S. Shells, p. 23, 
1845.—Lera, Obs., IV, pp. 11, 12, 1848.—Jay, Cat. 4th ed., p. 268, 1852.—Lewis, 
Proc. Phil. Acad., 1856, p. 259—Say, Binney, Reprint, pp. 56, 60, 1858.—MorseE, 
Amer. Nat., III, p. 651, pl. 11, fig. 17, 1870—Lewis, Proc. Phil. Acad., 1872, p.° 
109; Proc. Phil. Acad., 1872, p. 101—Scupper, Bull. Nat. Mus., 23, p. 200, 1885.— 
Ruoaps, Nautilus, XVIII, p. 66, 1904—Datt, Land & F.-W. She ape Osehourdaes 
1905.—Pitspry & Ferriss, Proc. Phil. Acad., 1906, p. 161—Baxer, Bull. Il. 
state Lab. N. H., VII, p. 103, 1906—Huinkx ey, Nautilus, XV, p. 40, 1906.— 
Pirspry & Ferrtss, Proc. Phil. Acad., p. 564, 1906—SirTH, Nautilus, XX, p. 91, 
1907.—StTERKI, Proc. Ohio State Acad. Sci, IV, p. 382, 1907.— HENDERSON, 
Nautilus, XXI, p. 7, 1907—Jacxson, Nautilus, XXI, p. 143, 1908.—BAKER, 
Science, n. s, XXVII, p. 943, 1908—LrErmonp, Shells of Maine, p. 37, 1908.— 
Cotton, Proc. Phil. Acad., 1908, pp. 413, 422, 446.—Baker, Nautilus, XXIV, 
p. 69, 1910. 
Lymnea columella Grrarp, Proc. Nat. Inst., I, p. 81, 1856.—CurrigrR, Sh. 
Grand River, Mich., 1859—Lerwis, Proc. Phil. Acad., 1860, p. 18.—Couper, 
Gateap 4: 
Limneus columella Grpses, App. Geol. Car., p. XX, 1848.—KUstTEr, Conch. 
Cab., p44. tar. 8, figs. 3-5, 1862. 
Lymneus columellus Say, Journ. Phil. Acad., II, p. 167, 1821—Sacer, 
Geol. Surv. Mich., p. 15, 1839—Say, Binney, Reprint, p. 65, 1858. 
Limnea columella Say, Nich. Encyc., IV, p. 56, 1819 (reprint ).—BEck, 
Index, p. 113, 1837——Potrez & Micuaup, Galerie, I; ps 216; pl: 22, fies. 15-16, 
1838.—Taytor & SHIveRICK, Cat., 1840——GouLp, Invert. Mass., p. 215, fig. 144, 
1841.—Prescott, Sh. Mass., No. 191, 1842—Reap, Cat., 1845.—RUSSELL, Journ. 
Essex Co., Nat. Hist. Soc., p. 130, 1852—CuicKerInc, List Sh. Portland, Me., 
1Until the anatomy of the European and other exotic species is known 
it is impossible to assign any of them to this group, although several species 
have similar shells. 
