498 Wisconsin Academy of Sciences, Arts,, and Letters. 



EXPLANATION OF PLATE XX. 



Fig. 1. Diaptomus leptopus: fifth foot of female (X 190). 



Fig. 2. Diaptomus leptopus: abdomen of female (X 158). 



Fig. 3. Diaptomus leptopus var. piscince: abdomen of female (X 76). 



Pig. 4. Diaptomus conipedatus : abdomen of female (X 185). 



Fig. 5. Diaptomus leptopus: terminal segments of right antenna of 



male (X 290). 

 Fig. 6. Diaptomus leptopus var. piscince: fifth feet of male (X 165). 

 Fig. 7. Diaptom,us leptopus : fifth feet of male (X 256). 

 Fig. 8. Diaptomus leptopus var. piscince: fifth foot of female (X 165). 

 Fig. 9. Diaptomus clavipes: fifth foot of female (X 165). 



