332 A. Alcock—Carcinological Fauna of India. [No. 3, 



2. Ischium of the external maxillipeds as well deve- 

 loped as the merus, the dactylus not enlarged. 

 The orbits are narrow slits situated dorsally 

 with their long axis almost at right angles with 

 the anterior border of the carapace, and the 



eyes are minute or obsolescent Xenophthalmus. 



3. Ischium of the external maxillipeds very much 

 larger than the merus, the appendages as a 

 whole being slender and not nearly closing the 

 buccal cavern. The orbits are in the usual 



marginal position Chasmocarcinops. 



Subfamily Xerophthalmia, nov. 

 Xenophthalmus, White. 



Xenophthalmus, White, Ann. Mag. Nat. Hist. XVIII. 1846, p. 177 : Milne 

 Edwards, Ann. Sci. Nat., Zool., (3) XX. 1853, p. 220: Burger, Zool. Jahrb., Syst. 

 VIII. 1894-95, p. 386. 



Carapace broader than long and broadest behind, arched antero- 

 lateral ly, the regions faintly indicated. Front narrow, strongly deflexed. 



The orbits are small, oblique or nearly longitudinal, button-hole like 

 slits, placed dorsally almost at right angles to the frontal border, and the 

 eyestalks are immovably embedded in them. The eyes are, at most, 

 minute specks of pigment. The antennules and antennae are extremely 

 small, the antennules folding nearly vertically beneath the front. 



Epistome not denned. Buccal cavern almost semicircular, com- 

 pletely closed by the external maxillipeds. The external maxillipeds 

 have the ischium and merus equally well developed (the ischium being 

 nearly square and the merus about a quadrant of a circle) and the 

 palp articulated at the antero-external angle of the merus. Exognath 

 small and concealed. 



Chelipeds in the male " with the hands somewhat elongated and 

 thickened," in the female short and very slender. 



Legs fairly stout, the third pair the longest. 



The abdomen in both sexes consists of seven separate segments. 



Key to the Indian species of Xenophthalmus. 



I. The legs are ciliated and the third (longest) pair are not 



twioe the length of the carapace • •• X. pinnoteroides. 



II. The legs are ciliated towards the tip only, and the third 

 (longest) pair are more than twice the length of the 

 carapace • X. obscurus. 



33. Xenophthalmus pinnoteroides > White. 

 Xenophthalmus pinnotheroides, White, Ann. Mag. Nat. Hist. XVIII. 1846, p. 178, 

 pi. ii. fig. 2, and Samarang Crust, p. 63, pi. xii. fig. 3 : Milne Edwards, Ann. Sci. 



