114 A. Alcock—Carcinological Fauna of India. [No. 1, 



The under surface of the carapace, below and external to the orbit 

 is, like the first lobe of the antero-lateral margin, eroded and granular 



Chelipeds unequal in both sexes : upper part of the outer surface 

 of arm with some fine transverse granular wrinkles ; upper and outer 

 surface of wrist and hand closely granular, the wrist and the upper part 

 of the hand being also eroded or pitted, most usually in a peculiar 

 honey-comb, fashion ; fingers stout, fluted. 



Legs rather thin : upper edge of merus sharp (almost subcristi- 

 form), often finely granular : carpus and propodite usually grooved and 

 ridged longitudinally (the propodite most distinctly so, and on both 

 surfaces): dactylus covered with close short fur. The sculpture of the 

 carpus and propodite, as of the chelipeds, is variable, even in specimens 

 from the same locality. 



Abdomen of male 5-jointed, the sutures between the 3rd-5th 

 somites nearly or quite obliterated. 



Colours in spirit : light yellow, fingers blackish brown with whitisli 

 tips. 



In the Indian Museum besides specimens from Hongkong, there 

 are 16 specimens from Mergui, Persian Gulf, and Karachi. Fourteen 

 little specimens from the Malabar Coast, 28 fms., are also probably 

 referable to this species. 



Tf this species is to be removed to Medseus on account of the erosion 

 and consequent indefiniteness of the orbital end of the antero-lateral 

 margin, Xantho floridus and more certainly Xantho tuberculaUis must 

 share the same fate, and Medmus must then be absorbed in Xantho. 



41 . Xantho bidenfattcs, A. Milne Edwards. 



Xantho bidentatus, A. Milne Edwards, Ann. Soc. Ent. France (4) VII. 1867, 

 p. 266: Miers, Challenger Brachyura, p. 126, pi. xi. fig. 4 : Ortmann, Zool. Jahrh. 

 Syst., VII. 1893-94, pp. 444, 449. 



Surface of carapace and appendages smooth (non-granular) : 

 gastric region well defined by fine shallow grooves, and very faintly 

 lobulated: branchial regions imperfectly separated from the hepatic 

 regions and very faintly and imperfectly areolnted. 



Of the four lobes of the antero-lateral margin the first two are 

 faint, broadly-rounded and coalescent, and the last two possess a small 

 acuminatum. 



Front prominent, notched in the middle line, to form two lobes, which 

 have the edge a little concave and the outer angle well pronounced. 



Under surface of carapace smooth to naked eye: the side wall, 

 above the articulations of the legs hairy. • 



