290 A. Alcock — Carcinological Fauna of India. [No. 2, 



visible from above, on the ventral aspect of the antero-external angle, 

 as well as a much smaller spinule on the dorsal aspect. There is also a 

 spinule, in the middle line, on the gastric region, and one on the cardiac 

 region, as well as one near the middle of either branchial region. 



The rostrum consists of two slender acute spines, which are about 

 one-fourth the length of the carapace proper, and are in the closest 

 contact up to the very tips. 



The eyes are movable forwards but are quite non-retractile back- 

 wards, and are in great part concealed beneath a large laminar 

 supra-ocular spine, which has its anterior angle produced forwards and 

 its posterior angle produced outwards. No post- ocular spine. 



[The spinule on the ventral surface of the hepatic angle is in no 

 sense a post-ocular spine.] 



The basal antennal joint is broad and has its outer edge irregu- 

 larly wavy, somewhat as in Dana's figure of Oregonia gracilis (IT. S. 

 Expl. Exp., Crust., I. pi. iii, fig. 26.) ; it sharp antero-external angle 

 is, like the following joints and the flagellum, plainly visible, from 

 above, beside the rostrum : the mobile portion of the antenna is rather 

 more than half the length of the carapace and rostrum. 



The chelipeds in the female are not stouter than the other legs, 

 and are shorter than the carapace and rostrum : their palm is nearly 

 twice the length of the fiugers, which meet only at the tip. 



The ambulatory legs all have slender joints and a strongly recurved 

 prehensile dactylus : the first pair, which are the longest, are, in the 

 female, a little longer than the carapace and rostrum. 



A single egg-laden female has the following dimensions : — 



Length of carapace and rostrum ... ... 6 - 2-(-2 = 8 , 2 millim. 



Greatest breadth of carapace ... ... ... 60 ,, 



Length of chelipeds ... ... ... ... ... 7 - ,, 



Length of first ambulatory legs ... ... ... 85 ,, 



Loc. Karachi. 



The place of the above genus in the " Key to the Indian genera of 

 the sub-family Acanthonychinss " (pp. 190 and 191 ante), is with Ruenia 

 and Mensethius, from both of which it is easily diagnosed ( 1) by the 

 P/sa- like rostrum, consisting of two sharp slender spines in the closest 

 contact throughout their extent, and (2) by the largo antennary flagel- 

 lum and by the eroded outer edge of the basal antennal joint. It has, 

 indeed, the closest natural relations with Mensethius. 



The unique specimen has only just been received along with the 

 " Investigator " collections of the season 1894-95. 



