GLOCHIDIA OK FRESHWATER MUSSELS. 

 Species with long period of gravidity . 



o From specimens taken by Mr. Clark in the Yellow River, Ind. 



t From specimens taken by Clark and Boepple in the Cumberland River, Ky. and Teun. 



Species with short period of gravidity. 



a Ohio River records by Mr. Boepple. 



While it is not mj" intention to take up the question of the meta- 

 morphosis of the glochidium while parasitic on the gills, or fhis, of the 

 fish, it is advisable to make brief reference to the record by Coker and 

 Surber (1911) ° of the growth of L. Ixvissima supplemented here with 

 a similar record for P. donaciformis. ^he sheepshead (Aplodinotus 



oOp. dt., Biological Bulletin, vol. xx, p. 179-182, pi. 1. 



