666 THE AMERICAN NATURALIST. [Vor. XXXIX. 
in Seneca Lake, N. Y.; L. desidiosa was obtained from Allen’s 
Creek, N. Y.; Z reflera was obtained from Long Lake, near 
Millers, Indiana, and Z. auricularia was secured in the green- 
house in Lincoln Park, Chicago. All but the last two were 
dissected in September. 
In the figures the different parts of the genitalia are desig- 
nated by the following letters: a/, albuminiparous gland; cm, 

Fic. 2.— Lymnea stagnalis jugularis opened from above, 
D showing the reproductive organs in 
their natural position. . p , 
columella muscle; fx, nerves to female organs; g, gizzard; /, 
liver ; m, mantle ; mn, nerves to male organs ; o, ovotestis ; ov, 
oviduct ; os, Ovisperm or hemaphrodite duct ; 5, penis ; pa, duct 
of prostate gland; Pr, prostate gland ; ps, penis-sac ; pmp, penis 
protractor muscles ; Pmr, penis retractor muscle; fy, pylorus ; 
rs, radula sac; s, spermatheca or receptaculum seminis; sd, 
eca ; æ, uterus; o, vagina; vd, vas deferens. 
The position of the genitalia is the same ın all of the species 
