Carcinological Fauna of India. 179 



arms sharply trigonal ; hands a good deal compressed ; fingers stout 

 and compressed, about half or two-thirds the length of the hand. 



The abdomen of the male consists, usually, of 3 pieces, that of the 

 female of 4. 



Key to the Indian species of Nursia. 



I. An oblique ridge crossing either hepatic region, 

 in addition to the longitudinal, transverse, and 

 epibranchial ridges : upper surface of hand 

 convex, but without a conspicuous median 

 ridge : — 



1. The posterior margin of the carapace 

 has the form of two blunt semicircular 

 lobes : the lateral margins are sinuous, 

 or only bluntly jagged : chelipeds in 

 the adult male less than twice the 

 length of the carapace : — 



i. Lateral margins jagged : front 

 with a coarse thickened granu- 

 lar edge, and not projecting 

 much beyond the eyes: carapace 



much broader than long N.plicata. 



ii. Lateral margins sinuous : front 

 in tbe form of a large ovate 

 snout, projecting far beyond the 

 eyes : carapace nearly as long 

 as broad : — 



a. Outer surface of wrist and 

 hand bluntly and incon- 

 spicuously carinate : rid- 

 ges of carapace coarse 

 and granular: snout semi- 



circularly rounded ... N. blanfordi. 



b. Outer surface of wrist 

 and hand sharply and 

 conspicuously cristate : 

 ridges of carapace clean- 

 cut : snout ovate-pointed N. nasuta. 



2. The posterior margin of the carapace 

 has the form of two sharp laminar 

 teeth : the lateral margins are sharply 

 jagged : front sharply 4-denticulate : 



184 



