390 THE AMERICAN MIDLAND NATURALIST 
Fic. 8. Proptera alata (Say) 9. Diagram of a gravid individual from 
Platte River, Agency Ford, showing animal characters in left 
valve. Coll. June 7, 1913. (34 Nat. size.) 
crenulations; conglutinates large, broken with ova or glochidia 
all through the mass; glochidia large, ax-head shape, with spine 
at each ventral corner of shell (0.220 x 0.380 mm.). 
Fic. ga. Lateral view of mature Fic. 9b. Anterior view of open 
glochidium of P. alata. (x87.) glochidium of P. alata. (x87.) 
