1895.] A. Alcock — Car etiological Fauna of India. 289 



Carapace hexagonal : the spines of the rostruni far apart : lateral 

 angles of the carapace in the form of stout outstanding spines the tips 

 of which are turned forwards : a pair of sharp tubercles in the middle 

 line behind the rostrum — these being tufted with hairs. 



Chelipeds stout, about twice the length of the carapace and ros- 

 trum, finely granular, and longitudinally grooved. 



A single specimen of this small species, from the Malacca Straits, 

 is in the Museum Collection. 



Appendix to sub-family ACANTHONYCHINjE. 



MENMTHI0P8, n. gen. 



Closely allied to Mensethius. 



Carapace pyriform, its surface smooth beneath a pubescent cover- 

 ing. The rostrum consists of two acute slender spines of moderate 

 length, which are in the closest contact throughout. 



The eyes, which are movable forwards but not retractile, are in 

 great pai-t concealed beneath a large, very conspicuous, laminar supra- 

 ocular spine. No post-ocular spine. [A spinule is present on the 

 ventral aspect of the hepatic region of the single species.] The basal 

 antennal joint is broad ; and the mobile portions of the antenna? are 

 visible, from above, on either side of the rostrum. 



The external maxillipeds have the merus as broad as the ischium, 

 and the palp inserted at the antero-internal angle of the merus. 



The ambulatory legs, of which the first pair are longer than the 

 rest, have strongly recurved prehensile dactyli. 



The chelipeds in the female (male unknown) are not enlarged. 



The abdominal segments in the female appear to be all distinct. 



This genus has a superficial resemblance to Oregonia, Dana ; but 

 in Oregonia tlaere is a large post-ocular spine, quite distinct from the 

 hepatic angle, and the eyes are said to be retractile against this spine. 



Mensethiops bicornis, n. sp. 



Body and legs tomentose, with additional long scattered seta?. 



Carapace pyriform, somewhat Acheeus-like in shape, there being 

 a slight constriction behind the eyes, and another slight constriction 

 behind the hepatic regions : the gastric and cardiac regions very promi- 

 nent, the branchial regions prominent : the surface, when denuded, 

 smooth, except for a granular ridge on the pterygostomian regions ; the 

 hepatic regions are laterally rather prominent, and carry a small spinule 



