1898.] A. Alcock — Carcinological Fauna of India. 113 



Abdomen of male five-jointed, the 3rd-5th somites fused ; (in 

 X. impress us the sutures are so distinct that the abdomen may appear 

 7- join ted). 



Key to the Indian species of the Genus Xantho. 



I. Chelipeds equal, or almost equal, in both sexes : — 



i. Legs crested, the crest sharp, or serrate, or 



crenate : length of carapace a good deal 



more than two-thirds the greatest breadth : 



lobules of carapace covered with convex 



subsquamiform tubercles Xantho (Lophoxanthus) 



scaberrimus, 

 r ii. Legs thick, sub-cylindrical, length of carapace 



less than two-thirds the greatest breadth : 



lobules of carapace smooth Xantho (Eudora) im- 



pressus. 

 II. Chelipeds unequal in both sexes : length of carapace 

 two-thirds, or a little more than two-thirds, the 

 greatest breadth : the 'legs may have sharp, but 

 never distinctly crested edges : — 



i. First two teeth of the antero-lateral margin 

 faint, obsolescent ; carapace and chelipeds 



smooth (non-granular) Xantho bidentatus. 



ii. Either the last three, or all four, teeth of 

 the antero-lateral margin distinct ; a large 

 part of the carapace and of the exposed 

 surfaces of the chelipeds wrinkled and 

 granular Xantho distinguendus. 



40. Xantho distinguendus, De Haan. 



Cancer (Xantho) distinguendus, De Haan, Faun. Japon. Crust, p. 48, pi. xiii. 

 fig. 7 : Heller, SB. Ak. Wien, XLIII. 1861, p. 323. 



Chlorodius distinguendus, Stimpson, Proc. Ac. Nat. Sci. Phila., 1858, p. 34. 



Xantho macgillivrayi, Miers, Zool. H. M. S. Alert, pp. 183, 211, pi. xx. fig. o. 



Lophozozymus (Lophoxanthus) bellus, var. leucomanus, Miers, Challenger 

 Brachyura, p. 115, pi. xi. fig. 1. 



Medxus distinguendus, de Man, Journ. Linn. Soc, Zool., XXII. 1887-88, p. 31 : 

 J. R. Henderson, Trans. Linn. Soc, Zool., (2) V. 1893, p. 359. 



Regions of carapace well delimited, fairly well divided into lobules : 

 the anterior and lateral parts of the carapace are covered with granular 

 transverse wrinkles which have almost a scaly look. 



Front cleft into two rather prominent, square-cut, sub-laminar 

 lobes. Antero-lateral margin cut into four sharply granular teeth, 

 •which may be all sharply acuminate, or the first may sometimes be 

 rather indistinct. • 



J. ir. 15 



