4110 iiii i HICAGO ACADEMY OF SCIENCES. 



part of Lake Michigan. After a northerly storm the beaches along 

 the lake arc strewn with the dead shells of Galba woodntffi. This is 

 especially true at Millers, Indiana, where the beach is very wide and 

 evenly sloping, and in the line of beach debris, this Lymnaea may be 

 found by thousands. It is very curious that not a single living speci- 

 men has as yet been found. 



It has been suggested by Cockerell (Nautilus XVI, p. 96) that 

 ivoodruffi might be a form of the European percgra, but a comparison 

 with authentic specimens of that species shows it to be quite different. 

 It is undoubtedly a native species. 



Galba decollata (Mighels). Plate XLII, figures 23-26; plate 

 XLI, figures 8-10. 



Limncea decollata Mighels, Proc. Bost. Soc. N. H., I, p. 49, 1841. — 

 Mighels & Adams, Bost. Journ. Nat. H., IV, p. 45, pi. 4, fig. 13 (four views), 

 1842.— Mighels, Bost. Journ. Nat. H., IV, p. 337, 1843.— Stimpson, Sh. N. Eng., 

 p. 52, 1851.— Chickering, List. Sh. Portland, Me., 1855 or 1856.— Bell, Geol. 

 Surv. Can., Rep. Prog., p. 252, 1859.*— Binney, Check List, p. 12, I860.— Whit- 

 eaves, Can. Nat. & Geol., VIII, p. 102, 1863.*— Binney, Land & F.-W. Sh. N. A., 

 II, p. 31, figs. 36, 37, 1865— Dall, Proc. Bost. Soc. N. H., XIII, p. 240, 1870.— 

 Smith & Prime, Ann. Lye. N. H., IX, p. 378, 1870.*— Gould, Invert. Mass., 

 Binney's Ed., p. 473, fig. 725, 1870.— Jeffreys, Ann. Mag. N. H., iv, X, p. 247, 

 1872.— Sowb., Conch. Icon., XVIII, Lim. sp. 42, pi. 6, fig. 42, 1872.— Tryon, 

 Con. Hald., Mon., p. 90 (64), 1872.— Jeffreys, Journ. Conch., I, p. 16, 1874.— 

 Westerlund, Vega Exp., IV, p. 165, 1885. — Chambers, Rep. Geol. & Nat. Hist. 

 Surv., Canada, 1882-84, p. 46, GG, 1885.*— Ottawa Nat., IV, p. 55, 1890.*— Taylor, 

 Ottawa Nat., VI, p. 33, 1892.*— Stearns, Proc. Nat. Mus., XXIV, p. 291, 1901. 



Limnea catascopium var. decollata Hartmann and Michener, Conchologia 

 Cestrica, 1874 (part). 



Lymncea decollata Wheatley, Cat. U. S. Sh., Ed. 2, p. 23, 1845. — Linsley, 

 Amer. Journ. Sci., XLVIII, p. 282, 1845.*— Jay, Cat., 4th Ed., p. 268. 18.52.— 

 Morse, Amer. Nat., Ill, p. 651, pi. 11, fig. 4, 1870.— Dall, Alaska Moll., p. 68, 

 1905.— Lermond, Shells of Maine, p. 38, 1908.— Berry, Nautilus, XXIV, p. 62, 

 1910.— Walker, Journ. Conch., XII, p. 240, 1909. 



Limnceus decollatus Kuster, Conch. Cab., Ed. 2, p. 45, taf. 8, figs. 12, 14, 

 1862 (figs. 11 & 13 are not decollata). 



Limnea decollata Haldeman, Mon. Limn., p. 52, pi. 14, figs. 1-3, 1842. 



Radix decollata Morse, Journ. Bost. Soc. N. H., I, p. 42, 1864. 



Neristoma decollata Tryon, Amer. Journ. Conch., I, p. 248, 1865. 



Limnea catascopium? Haldeman, Mon. Lim., p. 52, 1842 (non Say). 



Lymncea mighelsi Dall, Alaska Moll., p. 68, fig. 45, 1905 (non Binney). 



Shell : More or less ventricose, subovate or irregularly rhomboid, 

 thin to thick ; periostracum olivaceous green color ; some specimens 

 are almost jet black; surface shining, growth lines crowded, fine in 



♦These records marked with an asterisk are very doubtful. They probably 

 were based on short spired forms of catascopium. Specimens received from 

 Mr. F. R. Latchford are referable to the short spired form of catascopium. 



