18 



Marsh — On Two New Species of Diaptomus 



Explanation of Plate I. 



Fig. 1. Diaptomus mississippiensis — fifth foot of male X 163. 



2. 



3. 

 4. 

 5. 



6. 



abdomen of female X 163. 



fifth foot of female X 300. 

 birgei — fifth foot of male X 163. 

 fifth foot of female X 300. 

 terminal joints of male antenna 

 X300. 



