250 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 21 



4b. Dactyli of walking legs nearly as long as propodi 



Micropisa 



3b. Rostrum longer. Carapace narrower than 3a, distinctly 

 longer than broad 

 5a. Chelipeds more slender than ambulatory legs 



Lepteces 



5b. Chelipeds as stout as, or stouter than, ambula- 

 tory legs 



6a. First pair of walking legs much longer than 

 remaining pairs 

 7a. Carapace oval; antennae concealed by 



rostrum Chorinus 



7b. Carapace pyriform, four spines in a dia- 

 mond on widest portion ; antennae visible 



dorsally Notolopas 



6b. Walking legs diminishing regularly from first 



to last pair Nibilia 



2b. Seven male, five female free abdominal segments 



Holoplites 



lb. Intercalated spine absent ( Hyasteniinae of Balss) 



8a. Seven free abdominal segments in both sexes 



9a. Supraocular eave and postocular process not closely ap- 

 proximated 

 10a. Rostrum double 



11a. Rostrum bifid for more than half its length 

 12a. Rostral pines broad 



13a. Rostrum thin, flat, horizontal; 

 carapace lumpy . . Scyra 

 13b. Rostrum thick and deflexed ; cara- 

 pace hairy . Loxorhynchus 

 12b. Rostral spines slender 



14a. Two rows of spines on walking 

 legs .... Oplopisa 

 14b. Walking legs without two rows of 

 spines 

 15a. An infero-orbital spine 



Trachymaia 

 15b. No infero-orbital spine 



