1900.] A. Alcock — Carcinological Fauna of India. 341 



orbital portion, forms an upturned crest, so that the dorsal surface of tlie 

 cam pace is depressed and saucer-like. Other crests are found on the dorsal 

 surface of the cnrapace and, in the centre, a large mushroom-like tubercle. 



Though it is on an inferior plane, the narrow front is prominent 

 and not deflexed. 



The buccal cavern and mouth-parts have the same curious form, 

 except that (owing to the encroachment of the epistome in the middle 

 line) the anterior edge of the buccal cavern is bilobed or bow-shaped 

 rather than semicircular, and the dactylus of the external maxillipeds 

 is wanting or is represented by a few hairs. 



Distribution : Iudo- Pacific, from the east coast of Africa to Fiji. 



42. Xanthasia mtirigera, White. 



Xanthasia murigera, White, Ann. Mag. Nafc. Hist. XVIII. 1846, p. 177, pi. ii. 

 fig. 3: Dana, U. S. Expl. Exp., Crust, pt. I. p. 384, pi. xxiv. figs. 6 a-b : Milne 

 Edwards, Ann. Sc. Nat., Zool., (3) XX. 1853, p. 221: A Milne Edwards, Noav. 

 Archiv. du Mus. IX. 1873, p 321 : Hnswell, Cat. Austral. Crnst. p. 113 : Miers, Zool. 

 H. M. S. Alert, pp. 518, 546: de Man, Jonrn. Linn. Soc, Zool., XXII. 1887-88, 

 p. 106: Burger, Zool. Jahrb., Syst. VIII. 1894-95, p. 386, pi. x. fig. 33: Adensamer, 

 Ann. KK. Nat. Hofmus. Wien, XII. 1897, p. 109 : Nobili, Ann. Mus. Genov. (2) XX. 

 1899, p. 264. 



The edge of the carapace is formed, in all but its short fronto- 

 orbital portion, by a thin sharp upturned overhanging crest, which ends 

 in a curl on the anterior part of either branchial region. 



A large mushroom tubercle, having a rough or reticulate surface 

 and a more or less reniform outline, occupies the middle of the dorsal 

 surface of the carapace, and between this and the front is a pair of 

 parallel longitudinal crests. 



The front is somewhat prominent and is dorsally grooved or 

 obscurely bilobed, and on each side of it, beyond the small orbits, is a 

 small wing-like projection. 



Chelipeds not, or hardly, stouter than the legs : the dactylus in the 

 male is about two-thirds, in the female not much more than half the 

 length of the palm. 



Legs rather coarse : the first three pairs, which are about equal to 

 one another and to the chelipeds in length, are about as long as the 

 carapace, the fourth pair are a little shorter: the dactyli in all are 

 about equally short. 



In the female the broad abdomen is traversed longitudinally by a 

 sort of coarse interrupted carina. 



In the Indian Museum are 5 specimens from the Andamans and 

 Mergui. The carapace of the largest female is 11*5 millim. long and 

 15*5 millim. broad. 



