494 Wisconsin Academy of Sciences, Arts, and Letters. 



EXPLANATION OF PLATE XVIII. 



Fig. 1. Diaptomus minutus: abdomen of female (X 165). 



Fig. 2. Diaptomus shoshone: fifth feet of male (X 108). 



Fig. 3. Diaptomus shoshone: abdomen of female (X 68). 



Fig. 4. Diaptomus shoshone: terminal segments of right antenna of 



male (X 180). 

 Fig. 5. Diaptomus shoshone : fifth foot of female (X 108). 

 Fig. 6. Diaptomus Birgei: abdomen of female (X 165). 

 Fig. 7. Diaptom,us minutus: fifth feet of male (X 290). 

 Fig. 8. Diaptomus Birgei: terminal segments of male antenna (X 290). 

 Fig. 9. Diaptomiis siciloides: fifth foot of female (X 290). 



