Carciuologkal Fauna of India. 261 



Carapace almost oval transversely, and with the surface granular 

 or pustular. (In the young, besides tubercles, there are some coarse 

 spinules in five series — a median, and two oblique lateral on either 

 side.) The lateral borders are spinulate or crenulate anteriorly, spinate 

 posteriorly, smooth quite posteriorly at the junction with the posterior 

 border: the posterior border, except for a hook-like spinule at either 

 end, and two spinules in the middle line, is smooth : there are often one 

 or two curved spines on the branchial region : the pterygostomian region 

 is quite smooth, but on the inferior branchial region are a few coarse 

 spinules, most distinct at the bases of the legs. 



The rostrum, which is symmetrically trilobed, is very small, its 

 length being less than one-twelfth that of the rest of the carapace. 



The chelipeds, which are massive, are about four times the length 

 of the carapace in the male, about 3| times in the female : the mero- 

 podite is prismatic, or, in transverse section, rhomboidal ; its anterior 

 and posterior edges are armed with numerous, somewhat curved, spines 

 — alternating larger and smaller; its upper edge, as sometimes either 

 upper surface, has a row of spinules ; its lower edge is rounded, and has 

 a discontinuous series of spinules ; its under surfaces are smooth and 

 polished : the carpus has 3 or 4 sharp thin teeth on its outer margin : the 

 trigonal palm has twelve or more sharp thin laciniated teeth on its 

 outer edge — alternately larger and smaller; along its inner edge is a 

 long series of multicuspid spines ; its under edge is finely beaded, and 

 its under surfaces are almost smooth ; its upper surface has numerous 

 irregularly disposed spinules and granules : the dactylus has numerous 

 spinules on the outer surface of its broad base. 



The ambulatory legs have the merus compressed and spinulate as 

 to its edges, especially the posterior (inferior) edge : the longest of the 

 ambulatory legs is hardly longer than the meix>podite of the chelipeds. 



Colours in life, pale lilac dorsally, white ventrally. 



In the Museum collection are numerous specimens from the Madras 

 coast, from Arrakan and Mergui, and from the Andamans. 



Sub-genus Platylambrus, Stimpson. 



Platylambrus and Enoplolambrus, A. Milne -Edwards, Miss. Sci. Mex., Crust., 

 I. pp. 146 and 147. 



Lambrus, Miers, ' Challenger' Brachyura, p. 92 (part). 



Carapace carinated or tuberculated, broader than long, broadly 

 triangular with rounded sides and a broad but acute and projecting 

 rostrum : no post-ocular constriction : chelipeds with the meropodite 

 dan palm straight, the former joint prismatic, the latter sharply tri- 

 107 



