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



Very closely resembles G. quadrimaculata, but may be dia- 

 tinoruished from that species by the following characters : — 



(1) the length of the carapace is two-thirds the breadth : 



(2) the frontal teeth, in the adult are more acute : 



(3) the little lobule at the outer end of the lower border of the 

 orbit is not dentiform : 



(4) there is an acute spine on the posterior border of the carpus of the 

 last pair of legs (as well as the usual one on the merus) : 



(5) the 6th abdominal tergum of the male is, like that of G. annu- 

 lata, as long as broad, or nearly so, with the sides parallel or slightly 

 divergent in about three-fourths of their extent. 



For the rest, this species differs from 0. crucifera in the same 

 particulars as 0. quadrimaculata does, though the last spine of the 

 antero-lateral border is often more prominent than in G. quadrimaculata. 



In the Indian Museum are specimens, 22 in number from Mergui, 

 Andamans, Karachi and the Persian Gulf — besides 1 from Singapore 

 2 from Hongkong. The largest has the carapace 46 millim. long and 

 69 millim. in extreme breadth. 



But for high contrary authority I should have felt inclined to refer 

 this species to the Cancer fasciatus of Herbst (Krabben III. i. 62, pi. 

 xlix. fig. 5). 



33. Charyhdis (Goniosoma) affinis, Dana. 



Charyldis affinis, Dana, Proo. Ac. Nat. Sol. Philad. 1852, p. 85, and U. S. Expl. 

 Exp. Crust, pt. I. p. 286, pi. xvii. figs. 12 a-c. 



Ooniosoma afine, A. Mine Edwards, Archiv. du Mus. X. 1861, pp. 384, 385 : de 

 Man, Journ. Linn. Soc, Zool. XXII. 1887-88, p. 80, pi. V. fig. 2. and Zool. Jahrb., 

 Syst., VIII. 1894-95, p. 559 ; J. R. Henderson, Trans. Linn. Soc, Zool. (2) V. 1893, 

 p. 374. 



Differs from 0. crucifera in the following particulars ; — 



(1) the carapace is flatter, its transverse ridges are much more 

 distinct and there is an additional one across the cardiac region, and the 

 regions are better defined : 



(2 ) the frontal teeth are more acute and are not so parallel : 



(3) the first tooth of the antero-lateral border though distinctly 

 emarginate anteriorly has its inner angle acute, and the last tooth is 

 conspicuously larger and more prominent than the last but one, the 

 other teeth are more regularly cut and the antero-lateral border as a 

 whole is less oblique : 



(4) the inner angle of the lower border of the orbit is distinctly 

 dentiform : 



(5 ) the chelipeds are only about twice the length of the carapace 

 in the male : the hands are 6 or 7-costate and have 5 spines on the 



