I5<^ 



THE NAI/DES CF MISSOURI 



Fig. 8. Proptera alala (Say) 9. Diagram of a gravid individual from 



Platte River, Agency Ford, showing animal characters in left 



valve. Coll. June 7, 1913. (^ 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.). 



Fig. 9a. Lateral view of mature Fig. 9b. Anterior view of open 

 glochidium of P. alata. (xSy.) glochidium of P. alata. (X87.) 



