190 



Carcinological Fauna of India. 



retractile towards the post-ocular tooth, which, however, affords no 

 concealment. 



Chelipeds (in the female) hardly stouter than the ambulatory legs, 

 which are short, with prehensile dactyli. 



Two ovigerous females, the larger of which is 4 millim. long, from 

 off the Malabar Coast, 26 to 31 fathoms. 



The genus Collodes has hitherto been known only as a tropical 

 American genus. It has been found on both sides of Central America 

 so that its occurrence in Indian waters is not without precedent. 



Sub-family II. ACANTHONYCHIN^E. 



Eyes without true orbits : eye-stalks little movable, either short 

 and more or less concealed beneath a forwardly-directed sn.pra- ocular 

 spine, or obsolescent and almost or completely sunk either in the sides 

 of a hnge beak-like rostrum, or between low pre-ocular and post-ocular 

 excrescences (Sphenocarcinus) : a distinct post-ocular spine, which is 

 not cupped, may be present (Pugettia). Basal antennal joint truncate- 

 triangular. 



External maxillipeds with the merus as broad as the ischium, and 

 with the (small) palp arising from the antero-internal angle of the 

 merus. 



Dactyli of the ambulatory legs prehensile or sub-chelate, in the 

 former case the last three pairs of legs are often disproportionately 

 short compared with the second pair. Rostrum either simple or two- 

 spined. 



Key to the Indian genera. 



Rostrum of huge 

 size ; simple, or 

 bifid at tip ; not . 

 flanked on either" 

 side by salient su- 

 pra-ocular spines. 



I 



1. Eye-stalks al- 

 most obsolete, 

 completely sunk, 

 and almost or 

 quite immovable : ^ ii 

 carapace smooth 

 or tuberculate : no 

 post-ocular pro- 

 cess. 



I 



Carapace and 

 rostrum sub-cylin- 

 drical, the latter 

 bifid at tip Xenocarcinus. 



Carapace de- 

 pressed, elongate- 

 triangular : ros- 

 t r u m laterally 

 compressed, not 

 bifid at tip... 



Simocarcinus. 



2. Eye-stalks short, sunken but movable 

 between low smooth pre-ocular and 

 post-ocular excrescences : carapace with 

 huge symmetrical pedicled tablets Sphexocakcinus. 



SO 



