PLATE II. 



1. End of male antennae. 



Diaptomus castor. 



2. End ot abdomen, 

 Duipioinus giganteus. 



8. Antennule. 

 Male fifth foot. 

 Female fifth foot. 

 Spermatic tube. 



9. 

 10, 

 11. 



S, Caudal stylet, 



4. One pair of feet. 



5. Maxilliped. 



6. Maxilla. 



7. Mandible and palp. 



Potomoichetor fucosus. 



12. Female fifth foot. 



13. Female abdomen and egg-sac, 



14. Abdomen of young. 



15. First foot of Diaptomus giganteus, one branch drawn reverse. 



16. " " castor, " '' " 



