No. 465.] GENITALIA OF LYMNEA. 673 
Lymnea humilis Say. 
The genitalia of this small species appear in all respects like 
those of desidiosa. The receptaculum seminis is a rich salmon 
color, the prostate is whitish, and the rest of the organs are 
yellowish white. 
Lymncea mighelsi Binney.! (Fig. 9.) 
Male Organs. — Penis-sac cylindrical, very long and of large 
diameter. Penis long and slender, half the length of the penis- 


FıG.9— Genitalia of Zymnea mighelsi. The male organs are drawn somewhat nearer the 
f 1 h F^ + 
e 

sac. There is a single stout, ribbon-like retractor muscle attached 
1 The description of mighelsi is modified and corrected from that eed in 
Bull. .Chicago Acad. Sci., vol. 2, no. 5, p. 202. 
