Carcinohgiral Fauna of InHa. 357 



^- . _ Gelasimus per^lexm, Heller ( nee Edw.), Novara Crust, p. 38, pL v. fig. 4. 

 ;. ,?? Gelasimusininor, Ovren, Zoo\. K, II, S. "Blossom," Crast., p. 79, pi. xxiv. 

 fig8..2, 2a (1839) : Milne Kd wards. Aim. ScLNat., Zool., XVIII. 1852, p. 151 : Kingsley, 

 Proc. Ac. N.-ifc, Sci. Philad. 1880, p. 150, 



Vca. triangularis, Nobili, Ann. Mas. Genor. (2) XX. 1899, p. 274. 



Length of the carapace about four-sevenths of tlie greatest breacTth, 

 which is at the spine-like antero-lateral angles. 



Carapace strongly convex, almost hexagonal, the regions not indi- 

 cated. The posterior border of the dorsum of the carapace is less than 

 half the greatest breadth, hence not oiily the lateral borders of, the 

 dorsum of the carapace, but also the true lateral borders, are strongly 

 convergent posteriorly, the foimei- being defined by a fine raided line in 

 more than two-thirds of their extent. 



Front, as in G. annuUpes, from a fifth to a sixth the greatest 

 breadth of the carapace. 



Orbits sinuous, much oblique : the upper border defined by a fine 

 microscopically-beaded line, which is double in great part ; the lower 

 microscopically beaded, serrulate at its outer end. 



In the large cheliped of tiie adult male the hand is about 2^ times 

 as long as the carapace ; the outer surface of the arm, wrist, and hand 

 are smooth to the naked eye ; all the borders of the arm ai-e sharply 

 defined and finely serrulate, the inner border of the wrist is finely 

 serrulate, and the upper and lower borders of the palm are marginate 

 and gi-auulate, especially the upper border; and the two oblique 

 granular crests on the inner surface of the arm are in strong relief. 



In the lai'ge hand the dactylus, in the adult, is from li to Ij timies 

 the length of the upper boi'der of the palm ; its tip is simplj'^ hooked 

 and overhangs the simple upcurved tip of the immobile fi^nger. 



The meropodito of the last pair of legs is not nearly so broad as 

 that of the two preceding pairs. 



In the Indian Museum are 70 specimens, all but one being from 

 various parts of the Bay of Bengal littoral. The carapace of a large 

 specimen is 10 millim. long and about 18 millim. broad. 



The figures of G. minor, Owen, agi'ee very well with this species, 

 and if the two names should prove to refer (o the same species this name 

 has tke precedence. 



52. Gelasiimis teiragonum (Hei'bst).* 

 Cancer marinus, minor, vociferans, Seba, Thesaurus, III. p. 48, pi. xix. fig. 15. 

 Cancer tetragojion, Herbst, Krabben, I. ii. 257, pi. xx. fig. 110, and III. i. 31. 

 Oelasiwus tetragonnm, Riippell, 24 Krab. roth. Meer., p. 25, pi. v. fig. 5: Milne 



*■ I assume that Herbst used tetragonon as a noun substantiFe in apposition to 

 Cancer : it mnj therefore contiune in apposition to Oelasimos used as a substantive. 



699 



