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



Alliance IV. Xanthoida. 



Xantho. Etisus. Orphnoxanthus. 



Leptodius. Etisodes. 



Medaeus. 



Cycloxanthns. 



Hoploxanthus. 



Xantho, Leach. 



Xantho, Leach, Malac. Pod. Britt. pi. xi and text, 1815 ; and Trans. Linn. Soc, 

 XI. 1815, p. 320. 



Xantho, Desmarest, Consid. Gen. Crust., p. 104. 



Xantho, (part) and Eudora (part), De Haan, Faun. Japon. Crust, pp. 18 and 22. 



Xantho, (part) Milne Edwards, Hist. Nat. Crust. I. 387. 



Xantho, (part) Dana, U. S. Expl., Exp., Crust, pt. I. p. 166. 



Xantho, A. Milne Edwards, Ann. Sci. Nat., Zool., (4) XX. 1863, pp. 275 and 294 

 and Miss. Sci. Mex., Crust, p. 251. 



Xantho, Miers, Challenger Brachyura, p. 124. 



[Type Xantho floridus, Leach.] 



Carapace broad, moderately convex anteriorly, flat in the posterior 

 half ; the regions generally well delimited and fairly well lobulated in 

 the anterior two-thirds, but not posteriorly. 



Antero-lateral borders arched, usually cut into four teeth or lobes : 

 postero-lateral borders moderately convergent, not concave. 



Extent of fronto-orbital border half, or less than half, the greatest 

 width of the carapace : front about a fourth the greatest breadth of the 

 carapace. 



Front little deflexed, rather prominent, usually sublaminar, notched 

 in the middle line, usually separated from the supra-orbital margin by a 

 notch or groove. 



Orbital margin with two (often indistinct) suture lines above and 

 one (more distinct) just below the outer angle: usually a prominent 

 tooth at the inner angle of the lower edge of the orbit. Eyes on short 

 thick stalks. 



Basal antennal joint short, meeting the front at the inner angle : 

 the flagellum, which is about as long as the orbit, lodged in the orbital 

 hiatus. 



Anterior edge of merus of external maxillipeds nearly transverse, 

 with commonly a small tooth near the antero-internal angle. 



Chelipeds either unequal in both sexes, or less commonly equal in 

 both sexes (Xantho impressus, Xantho scaberrimus) ; fingers pointed. 



Legs subcylindrical, with the upper edges often sharp (crested in 

 Xantho scaberrimus.) 



