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



and incompletely indicated, strongly convex fore and aft and anteriorly 

 declivous. 



Pronto-orbital border about two-thirds tlie greatest breadth of the 

 carapace : anterolateral borders sharp, entire, curved : postero-latei al 

 borders parallel. 



Front about a third the greatest breadth of the carapace, its free 

 edge slightly arched, notched in the middle line. 



The orbits are in the usual position and the eyestalks are immov- 

 ably fixed in them, but the eyes are fairly well formed, though they 

 may be deficient in pigment. The antennules fold transversely in 

 proper pits. The basal antenna-joint is short : the flagellum, which is 

 of good length, stands in the orbital hiatus. 



Epistome well formed and prominent: buccal cavern quadrilateral, 

 slightly increasing in breadth from behind forwards, almost completely 

 closed by the external maxillipeds, the merus of which has the antero- 

 external angle much produced and carries the flagellum at the antero- 

 internal angle. 



Chelipeds subequal, more massive but decidedly shorter than the 

 legs; the palm short, deep, and compressed. 



Legs slender, unarmed, the 3rd pair the longest : dactyli styliform. 



The abdomen in both sexes consists of 7 separate segments and 

 does not nearly occupy the space between the last pair of legs. 



Distribution : Indo-Pacific from the Bay of Bengal to Ecuador. 



Key to the Indian species of Ceratoplax. 

 I. Surface of carapace nude, eyes well pigmented : outer 



surface of palm polished and nearly smooth C. ciliata. 



II. Surface of carapace tomentose, eyes deficient in pigment : 

 rows of vesiculous granules on the outer surface of the 

 palm ... , ... C. hispida. 



22. Ceratoplax ciliata, Stimpson. 



Ceratoplax ciliatus, Stimpson, Proc. Ac. Nat. Sci. Philad. 1558, p. 96 : A. 0. 

 Walker, Journ. Linn. Soc, Zool., XX. 1890, p. 110. 



Ceratoplax ciliata, Miers, Challenger Brachyura, p. 234, pi. xix. fig. 3 : Cano, 

 Boll. Soc. Nat. Napol. III. 1889, p. 229. 



Carapace, chelipeds and legs rather scantily fringed with hairs, but 

 with a nude surface. 



Carapace, length a little more than three-fourths the greatest 

 breadth, sparsely punctate, the regions not distinguishable. Front 

 about a third the greatest breadth of the carapace, its free edge slightly 

 arched and notched in the middle line. Eyes well pigmented. Cheli- 

 peds decidedly shorter than the legs : inner angle of wrist sharp, but 



