STALK-EYED CRUSTACEA 215 



legs not elongated ; the sixth joint less than twice as long 

 as wide. 



Costa Rica. 



16. Pseudothelphusa chilensis. 



Potamia chilensis . A. Milne Edwards and Lucas. 



Superior margin of front not keeled, tuberculated. 

 Fourth joint of external maxillipede narrow, the outer 

 oblique margin making an angle with the anterior margin. 

 Cervical suture curved. 



Peru, Lima. 



17. Pseudothelphusa nobilii. 



Superior margin of front not keeled, tuberculated. 

 Fourth joint of external maxillipedes narrow, the outer 

 oblique margin making an angle with the anterior margin ; 

 no outer orbital notch. Cervical suture straight. Walking 

 legs slender. 



Ecuador. 



18. Pseudothelphusa bouvieri. 



Superior margin of front not keeled, tuberculate. 

 Fourth joint of external maxillipedes narrow ; the outer 

 oblique margin making an angle with the anterior margin. 

 A well - marked outer orbital notch. Cervical suture 

 straight. Walking legs of moderate width. 



United States of Colombia. 



19, Pseudothelphusa agassizii. 



Carapace coarsely granulate, Superior margin of 

 front not keeled, tuberculate, unilobate, with median 



