390 Carcinological Fauna of India. 



B. Exognath of the external maxillipeds 

 as broad as or broader tbau the ischi- 

 ognath : daetyli of the legs com- 

 pressed but not broadened : — 

 a. Carapace flat and depressed .... Ptychognathus. 

 h. Carapace deepish, strongly con- 

 vex in both directions Pyxidognathus. 



2. An oblique hairy ridge on the exposed surface of 

 the external maxillipeds (Sesarininx) : — 



i. Carapace little, sometimes not at all, broader 

 than long, the pterygoatomian regions and 

 sidewalls with a sieve-like reticulation : lower 

 border of orbit not abnormally prominent : — 



A. Antennae lodged in the orbital hiatus : — 



a. Carapace neai-ly square : front 

 abruptly and vertically de- 

 flexed Sesaema. L-I^^ 



h. Antei'o-lateral borders of cara- 

 pace arched : front obliquely 

 deflexed Sarmatium. Li 2.,^ 



B. The tooth at the inner angle of the 

 lower border of the orbit meets the 

 front, so as to exclude the antennae 

 from the orbit : — 



ct. Cai'apace dorsally smooth and 



nude JIetasesarma. 



b. Carapace dorsally verrucose and 



densely tomentose Clistoc(ELOMA. v) 



ii. Carapace much broader than long, the ( 



pterygostomiau regions, etc., not retici^lated : 

 lower border of orbit prominent beyond the 

 front. Front gradually declivous. General 



appearance much like MacrophthalmUs Mktaplax. ^'bO 



II. The antennules fold nearly longitudinally in deep notches 

 in the front visible in a dorsal view {Plagusiinie) :— 



1. Merus of the external maxillipeds of good size and 



as broad as the ischium Plagdsia. LLoh 



2. Merus of the extei-nal maxillipeds small and much 

 narrower than the ischium Liolophus. 



Sub-family GRAPSiNiE, Dana (pt.). 

 Grapsds, Lamk,, Kingsley. 



Grapsus (part) Lamark, Syst. Anim. Sans Vertebr. : Latreille, Hist. Nat. Crust, 

 et Ins. VI. p. 56, and Gen. Crust, p. 32. 



Grapsus, Leach, Trans. Linn. Soc. XI. 1815, pp. 309, 323. 



Grapsus (part) Desmarest, Consid. Gen. Crust., p. 129, and Diet. Sci. Nat. 

 XXVIII. p. 247 : Milne Edwards, Hist. Nat. Crust. II. 83, and Ann. Sci. Nat,, Zool., 

 (3) XX. 1853, p. 166 : Dana, U. S. Expl. Exp. Crust, pt. I. p. 336. 



732 



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