STALK-EYED CRUSTACEA 85 



Subgenus i. Nemausa. 

 Subgenus 11. Mithrax. 



Synopsis of the Subgenera and the Species. 



I. Carapace longer than broad. 



Rostrum well developed. 



Long spines on distal end of basal joint of external 

 antennae. First pair of legs of moderate size. — (Subgenus 

 N email sa.') 



1. Carapace almost smooth. Prreocular spine short. — 

 (J/, rostrata.) 



II. Carapace transverse. Spines of rostrum short or 

 wanting. Short spines on distal end of basal joint of 

 external antennae. First pair of legs often large. — (Sub- 

 genus Mithrax.) 



A. Carapace with the branchial regions not dorsally 

 sulcated ; the lateral margin usually armed with spines. 



a. Spines of rostrum distinct, acute. Palm of hand of 

 first pair of legs with or without spines on superior 

 margin. 



rt\ Palms with spines on superior margin. 



2. Carapace covered with spines. — {M. spinosissinnis.) 



3. Carapace tuberculous, — {AI. coiniutus^ 



4. Carapace covered with large round granulations. — 

 (^M. aadeatus.) 



b. Spines of rostrum short or wanting. First pair of 

 legs with the palms unarmed. 



U^. Two spines on basal joint of external antennae. 



5. Carapace with a few spines on upper surface. — i^M. 

 /lispidiis.) 



6. Carapace flat. — {M. dcpjrssus.) 



7. Spines on border of carapace broad and tuber- 

 culous. — (^M. pleiiracantlnis.) 



