Carcinological Fauna of India. 



191 



II. Rostrum flanked 

 on either side by 

 salient supra-ocu- 

 lar spines ; either 

 long and simple, , 

 or consisting olP 

 two spines of mo- 

 derate length : no 

 post-ocular pro- 

 cess. 



f i. Rostrum laterally- 

 compressed, su- 

 pra-ocular spines 

 small : eye-stalks 

 so short and deep- 

 ly sunken as to 

 hardly reach to the 

 sides of the cara- 

 pace ; carapace of 

 the female with 

 large foliaceous 

 lateral lobes Huenia. 



. Rostrum horizon- 

 tally compressed, 

 supra-ocular 

 spines large : eye- 

 stalks short, but 

 reaching beyond 

 the sides of the 

 Carapace : cara- 

 pace of the female 

 without foliaceous 

 L lobes Men^thius. 



2. Carapace broad, sub-quadrangxilar: ros- 

 trum short and deeply bifid, ambulatory 

 ^ legs subchelate Acanthonyx. 



Carapace elon- 

 ga t e -t r i angular, 

 rostrum elongate, , 

 simple : ambula- ' 

 tory legs not sub 

 chelate. 



Xenocarcinus, White. 



Xenocarcinus, White, Jukes' Voyage H. M. S. ' Fly,' Vol. II. p. 335. 

 Huenioides, A. Milne-Edwards, Ann. Soc. Entomol. France (4) V. 1865, p. 144. 

 Xenocarcinus, Miers, Journ. Linn. Soc, Zool., Vol. XIV. 1879, p. 648, pi. xii. 

 fig. 5. 



Carapace ovate-subcylindrical, tapering to a long thick subcylin- 

 drical rostrum, or beak, the tip of which is einarginate or bifid. 



Eyes short, completely sunken in the sides of the rostrum, almost 

 immovable : no prse-ocular or post-ocular spines. 



Antennas with the basal joint triangular, and with the short mobile 

 portion hidden beneath the rostrum. 



External maxillipeds with the merus as broad as the ischium and 

 giving attachment to the palp at its antero-internal angle. 



Chelipeds not much shorter or stouter than the 2nd and 3rd pairs 

 of legs : 4th and 5th pairs of legs short : all with the dactyli short, 

 stout, curved, and sharply toothed along the posterior surface. 



Abdomen of the female four-joiuted, the 3rd — 6th segments being 

 fused together. 



37 



