OF NORTH AMERICA. 183 



The species was first found in the greenhouse by Mr. Herbert E. 

 Walter, the instructor in Biology in the Robert A. Waller High School, 

 Chicago, in 1901. It was imported on plants from Belgium and has 

 thrived well in captivity, increasing to such an extent as to furnish 

 an abundance of material for the biology classes in the above named 

 high school. It has also been found in a lily pond in the park, the 

 water of which was artificially heated to 90 Fahr. The mantle shows 

 conspicuously through the shell in irregular patches of dark and light 

 spots. It will probably be found in other greenhouses in the United 

 States and there is no reason why it would not thrive in the ponds 

 and rivers of certain favorable sections of the country. The Brooklyn 

 colony has evidently become well established in the open, and, if the 

 environment is favorable, it may become a recognized part of the 

 molluscan fauna. 



Genus BULIMNEA Haldeman. 1841. 



1841. Bulimnea HALDEMAN, Mon. Limn., part 3, p. 6, July, 1841. Type Limnea 



megasoma SAY. (Not of H. A. Adams.) 



1865. Bulimnea BINNEY, L. and F. W. Sh. N. Amer., II, p. 37. 



1870. Bulminea BALL, Ann. Lye. Nat. Hist., N. Y., IX, p. 349. 



1872. Bulimnea TRYON, Con. Hald. Mon., p. 86 (60). 



1876. Bulimnea MEEK, U. S. Geol. Sur. Terr., IX, p. 532. 



1880. Bulimnea CR. & FISCH., Mis. Scient. Mex., II, p. 51. 



1884. Bulimn&a TRYON, S. and S. Conch., Ill, p. 101. 



1905. Bulimnea DALL, Alaska Mollusks, p. 63. 



1908. Bulimnea BAKER, Science, N. S., XXVII, No. 703, p. 943, 1908. 



SHELL: Bulimiform, very solid, generally richly colored; spire 

 and aperture about equal in length; outer lip simple; axis twisted, 

 inclining to gyrate, the fold quite sharp ; inner lip expanded and folded 

 back, completely closing the umbilicus. (PI. XVIII, fig. 8.) 



JAW: With a wide, slightly convex median swelling. (PL VI, 

 fig. E.) 



RADULA: With tricuspid lateral teeth. (PL VII, fig. D.) 



GENITALIA : Penis-sac large, the penis one-fourth longer than the 

 penis-sac and enlarging gradually to the end, which is club-shaped and 

 not rounded, as in the other members of the family; penis-sac retrac- 

 tors one or two in number, penis-sac protractors very numerous; 

 prostate very large, long, irregularly flattened, the posterior portion 

 short ; first accessory albuminiparous gland roundly knob-shaped, taper- 

 ing toward the vaginal opening; the oviduct emerges from this gland 

 some distance from the termination of the rounded portion. (PL X, 

 fig. D.) 



DISTRIBUTION : Nearctic. 



