1900.] A. Alcock — Carcinologieal Fauna of India. 359 



The " Challenger " specimens referred by Miers to this species 

 have a broad front and are identical with specimens from Hongkong 

 that I take to be G. splendidus. 



53. Gelasimus Marionis, Desm. 



Gelasimus Marionis, Desmarest, Consid. Gen. Crust., p. 124, pi. xiii. fig. 1, and 

 Diet. Sci. Nat. XXVIII. 1823, p. 243: Milne Edwards, Ann. Sci. Nat., Zool., (3) 

 XVIII. 1852, p. 145, pi. iii. fig. 5 (nee Hist. Nat. Crust. II. 53): de Man, Notes 

 Leyden Mus. II. 1880, p. 67: Miers, Ann. Mag. Nat. Hist. (5) V. 1880, p. 308 : 

 Kingsley, Proc. Ac. Nat. Sci. Philad. XXXII. 1880, p. 141, pi. ix. fig. 8. 



Gelasimus cidtrimanus, White, P. Z. S. 1847, p. 205, Ann. Mag. Nat. Hist. XX. 

 1847, p. 205, and Samarang Crust, p. 49 (apud Miers loc. cit. supra}. 



Gelasimus cidtrimanus var. Marionis, Ortmann. Zool. Jalirb. Syst. VII. 1893-94, 

 pp. 750, 754. 



Length of the carapace about two-thirds of the greatest breadth, 

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



Carapace little convex, all its regions very well defined, the 

 posterior border of its dorsum in the adult male is half its greatest 

 breadth and the true lateral borders are moderately convergent posteri- 

 orly : the fine raised line that in some other species defines the greater 

 part of the dorsal plane is here, in the adult male, confined to the 

 neighbourhood of the antero-lateral angles. 



The breadtli of the front between the bases of the eyestalks is no* 

 a fifteenth the greatest breadth of the carapace. 



Orbits not very oblique nor very sinuous ; the lower border, which 

 is nearly straight, is elegantly crenulate throughout. 



In the large cheliped of the adult male the upper border of the arm 

 is prominent and the inner border ends in a sharp tooth, independent of 

 the terminal constric ted-off lobule ; the upper surface of the wrist is 

 granular, and the inner border of the wrist has a denticle or spinule 

 at its angle; and the haud (fingers included) is about three times the 

 length of the carapace. 



This large hand has a curious twist : its palm is compressed and 

 has the upper and lower margins well defined, the outer surface 

 covered with large granules, and the two granular crests on its inner 

 surface fairly prominent : its fingers are broad thin and laminar ; the 

 dactylus, which may be four times as long as the upper border of the 

 palm, is shaped like a knife-blade ; and in the immobile finger, which 

 has a groove or line of pits along its outer surface, the dentary edge has 

 a simple S-shaped curve. 



The merus of the last pair of legs is not at all foliaceous. 



In the Indian Museum are 9 specimens from the Andamans. The 

 carapace of a large specimen is 18'5 millim. long and 265 milling broad. 

 J. ii. 47 



