CRUSTACEA OF THE MERGUI ARCHIPELAGO. 107 
crabs presents a somewhat different appearance from the cepha- 
lothorax of X. murigera, I am inclined to regard them as a distinct 
species. They differ from it in the following characters :—The 
crests or ridges are rather rounded and not thin or acute, and the 
anterior curls are indistinct or quite absent; they also pass into 
the raised, broad, and nearly straight, posterior margin, which 
projects much more backwards than in X. murigera, and forms 
a right angle with the lateral margins. The length of the 
carapace in these specimens therefore measures more than the 
distance between the raised lateral margins. 
The legs also are more elongated and more slender than in 
typical representatives of X. murigera, all the joints presenting 
this character, especially the hands and the meropodites, carpo- 
podites, and propodites of the ambulatory legs. 
The integument not being strong and solid, but rather pliant 
and similar to parchment, I am inclined to regard the different 
shape of the carapace as an individual variety. I do not venture 
to decide this question, but, as the tegs are also more slender 
and more elongate than those of Xanthasia murigera, these 
Specimens may perhaps prove to represent a distinct species, for 
which I would propose the name of Xanthasia Whiter. 
Dimensions of the larger ova-bearing specimen :— 
iieneth of the cephalothorax................ 14 millim. 
Distance between the raised lateral margins .. 124 
Length of the legs of the antepenultimate pair 22 
Length of the hands, the fingers included .... 7 
99 
99 
99 
Genus Ocypopa, Fabr. 
69. OcYPODA CERATOPHTHALMA, Pallas. 
Cancer ceratophthalmus, Pallas, Spicil. Zool. fase. ix. p. 83, pl. v. 
he, 17 (17/72). 
Ocypoda ceratophthalma, Fabricius, Suppl. Entom. Syst. p. 347 ; 
Milne-Edwards, Hist. Nat. des Crustacés, t. ii. p- 48, and Ann. Sci. Nat. 
3¢ série, t. xvii. p. 141. 
Ocypoda ceratophthalma, de Man, Notes from the Leyden Museum, 
vol. ii. 1881, p. 245. 
Ocypoda ceratophthalma, Miers, Ann. § Mag. Nat. Hist. 5th ser. vol. x. 
1882, p. 379. 
Twenty specimens of this common Indian species were col- 
lected, all being very young, except one nearly adult female. 
