1899.] A. Alcock — Garcinological Fauna of India. 51 



B. Last spine of the an tero- lateral border far larger 



than any of the others G. hoplites. 



III. The lobular process of the basal antenna-joint does not 

 nearly touch the front, so that the flagellum stands in 

 the upper part of the orbital hiatus (Oonioneptunus) : — 



A. Posterior border of dorsum of carapace forming 

 an angular junction with the postero-lateral 

 borders : the posterior border of the arm ends 

 in a spine : — 



1. Transverse ridges of carapace faint : a 

 large red impermanent spot on either 



branchial region G. truncatus. 



2. Transverse ridges of carapace promi- 

 nent : a persistent small dark brown 



spot on either branchial region , G. bimaculatus. 



B. Posterior border of dorsum of carapace forming 

 a curve with the postero-lateral borders : no 

 spine on the posterior border of the arm : 

 carapace little transverse, the extent of the 

 fronfco-orbital border nearly equal to the 



greatest breadth of the carapace G, investigatoris. 



[Besides the species mentioned in the above Key, other two, which 



I have not seen, are included in the Indian Fauna by other authors. 

 They are G. enjthrodactylum (Lamk.) and G. sexdentatum (Herbst) 

 A. M. E. 



G. erythrodactylum is recognized, according to A. Milne Edwards, 

 by having seven teeth, of which the second and fourth are rudimentary, 

 on the antero-lateral borders. 



G. sexdentatum, A. Milne Edwards, if not of Herbst, is very proba- 

 bly the same as de Man's G. merguiense.'] 



28. Charyhdis (Gomosoma) crucifera, (Fabr.) A. M. Edw. 



Rumph, Amboinsche Rariteitk, pi. VI. fig. P. 



Cancer sexdentatus, Herbst, Krabben pi. viii. fig. 53 (1790). 



Cancer cruciatus, Herbst, Krabben pi, II, V. 155, pi. xxxviii. fig. 1 (1794.) 



Portunus crucifer, Fabricius, Ent. Sjst, Suppl. p. 364 (1798) ; Bosc, Hist. Nat, 

 Crust. I. p. 218: Latreille, Hist. Nat, Crust. VI. p. 14 and Encycl. Meth. X. p. 191. 



Thalamita crucifera, Milne Edwards, Hist. Nat, Crust. I. 462 : Lucas, Hist. Nat. 

 Anim. Art. Crust, p. 104 : Haswell, Cat. Austral. Crust, p. 81. 



Oceanus crucifer, De Haan, Faun. Japon. Crust, p. 40. 



Charyhdis crucifera, Dana, U. S. Expl. Exp. Crust, pt. I. p. 286, pi. xvii. fig, 



II a-c: Stimpson, Proo. Ac. Nat. Sci. Philad. 1858, p. 39. 



Goniosoma cruciferum, A. Milne Edwards, Archiv. du Mus. X. 1861, pp. 371. 

 385: Tozzetti, "Magenta" Crust, p. 82, pi. vi. fig. 2 a-g : Nauck, Zeits. Wiss. 

 Zool. XXXIV. 1880, p. 61, pi. i. fig. 27. {gastric teeth) : Muller, Ver. Ges. Nat. 

 Basel, VIII. 1886. p. 475 : Miers, " Challenger " Brachynra p. 191 : de Man, 

 Archiv. f. Naturges. LIII. 1887, 1. p. 334, and Journ. Liuu. Soc, Zool., XXII. 1887, 



