1899.] A. Alcock — Carcinological Fauna of India. 65 



Oonioaoma ornatum, A. Milne Edwards. Archiv, dn Mub. X. 1861, pp. 376, 385 : 

 Miera, P. Z. S. 1879, pp. 20, 33, and Challenger Brachyura p. 191 : Ortmann, Zonl. 

 Jahrb, Syst., VII 1893, p. 83 : J. R. Henderson, Trans. Linn. Soc, Zool., (2) V. 

 1893, p. 376 : de Man, Zool. Jahvb., Syst., NTIII. 1895, p. 562. 



A smalli.sh species : the length of the carapace in adults is abont 

 26 raillim., its extreme breadth about 36 millim. 



Length of carapace rather over two-thirds the extreme bread ih. 

 Carapace moderately convex with the regions fairly well defined, crossed 

 transversely by well marked granular ridges which have much the 

 same disposition as those of G. crucifera, except that there ai-e in 

 addition (1) a broad one — divided in the middle line — on the cardiac 

 region, and (2) a short and broad one — or traces of two — on eitlier 

 branchial region. 



The front is cut into eight lobes {including the inner supra-orbital 

 angles) arranged in four pairs, of which the outermost pair on eitlier 

 side a.re bluntly dentiform, and the two middle pairs are broad shallow 

 and lobe-like. 



The antero-lateral borders are cut into six teeth (including the 

 outer orbital angles) of which the first is obliquely truncated and the 

 last is the smallest : the edges of all are entire. 



The posterior border of the dorsum of the carapace is straight, and 

 forms a somewhat up-turned or dog's-eared angle of j auction with the 

 postero-lateral borders. 



The orbits have a strong dorsal inclination and their major dia- 

 meter is not much less than half the width of the inter-orbital space : the 

 inner angle of their lower border is broad and hardly dentiform. 



The chelipeds are about 2| times the length of the carapace (in 

 the male) and all their surfaces are covered with granular transverse 

 squamiform markings. There are 2 — less commonly 3 — enlarged spines 

 on the anterior border of the arm and the posterior border ends in a 

 spinule. Inner angle of wrist strongly spiniform, three spinules on the 

 outer angle. Hand 6 or 7 costate — the costae with squamiform crena- 

 tions — and with 4 spines on the upper surface. In adults the palm is 

 full and is longer than the fingers in the larger cheliped, but shorter 

 than the fingers in the smaller cheliped. 



Merus of last pair of legs about two-thirds as broad as long, with 

 the usual strong spine on the posterior border: the same border of the 

 propodite is finely serrated. 



In both sexes the 2nd and 3rd — and to a much less extent the 4th — 

 abdominal terga are transversely keeled : the 6th tergum iu the male 

 is broader than long and has strongly curved sides. 



In the Indian Museum are 6 fine specimens from the mouth of the 

 J. II. 9 



