Eyes without orbits ; the eye-stalks usually long and slender, and 

 affords no concealment. The basal joint of the antennas is extremely 

 (in Platymaia apparently trifid). 



Alliance I. Leptopodioida. Antennas with the basal joint usuall; 

 with the merus narrower than the ischium, and often with a large coe 



Carapace of the 

 typical O x y - 

 rhynch shape, 

 elongate -trian- 

 gular or pyri- 

 form. 



fi, Chelipeds both mai-kedl 

 the carapace : post-ocular 



r 



. Carapace well- 

 calcified, not 

 depressed : ros- 

 trum separated 

 from the cara- 

 pace by a dis--i 

 tinct post-ocular 

 constric tion, 

 which sometimes 

 forms a long 

 " neck " 



i. Chelipeds ne- 

 ver approaching 

 the longest legs 

 in length : ros- 

 trum bifid and 

 never approach- , 

 ing the carapace ' 

 in length : post- 

 ocular neck, 

 when distinct, 

 short. 



<.. Free 

 the ant 

 duncle 

 cylindi 

 not coa 

 sute : ( 

 almost 

 rostrui 

 tal. 



b. Fret 



rostru 



2. Carapace semi-membranous, exceedingly de] 

 ^ the last pair of legs subdorsal in position 



II. Carapace nearly circular. [Epistome narrow : a large post-ocular 

 nal joint perfectly free, legs long, with much flattened blade-like , 



Alliance 2. Inachoida. Antennas with the basal joint flattened or co 

 external angle produced to form a spine which is visible from abo 

 broader than the ischium, and with the palp small. 



1. Rostrum simple : post-ocular spine small : basal antennal spine 

 moderate, 



II. Rostrum bifid : post-ocular spine large : basal antennal spine large 



