1895.] A. Alcock —Carcinological Fauna of India, 193 
Sphenocarcinus, A. Milne-Edwards. 
Sphenocarcinus, A. Milne-Edwards, Miss. Sci. Mex., Crust., I., p 135. 
Sphenocarcinus, Miers, Journ. Linn. Soc., Zool., Vol. XIY. 1879, p.663; and 
‘ Challenger ’ Brachyura, p. 34. 
Carapace elongate sub-pentagonal, broad behind, tapering in front 
to a long rostrum formed of two spines (fused together to near the tip). 
The surface of the carapace is symmetrically and deeply honey-combed 
by broad deep channels which leave symmetrical tubercles with over¬ 
hanging edges between them. 
There are no true pre-ocular and post-ocular spines, but the eye is 
deeply sunk between two’low smooth excrescences which are pre-ocular 
and post-ocular in position. 
The basal antennal joint is truncate-triangular, and the antennary 
flagella are completely hidden beneath the rostrum. The epistome is 
long and narrow. The external maxillipeds have the merus as broad 
as the ischium, somewhat dilated at the antero-external angle, and 
somewhat excavated at the antero-internal angle for the insertion of the 
small palp. The chelipeds are not much stouter, and not much shorter 
than the next pair of legs, which are the longest: the* dactyli of the 
legs, though stout recurved and prehensile, are not toothed along the 
posterior edge. Abdomen, in both sexes, seven-jointed. 
Oxypleurodon Miers (‘Challenger’ Braehyura, p. 38) differs from 
Sphenocarcinus only in the form of the rostrum, the spines of which are 
divergent instead of convergent and more or less fused. I much suspect 
the generic value of this character. If, however, the two forms be iden¬ 
tical, then Sphenocarcinus would have to be removed to the next sub¬ 
family, in which case the sub-family Acanthonychinee would be perfect¬ 
ly homogeneous. 
Sphenocarcinus cuneus (Wood-Mason). 
Oxypleurodon cuneus, Wood-Mason, Ann. Mag. Nat. Hist., (G) VII. 1891, p. 261. 
Carapace elongate sub-pentagonal, narrowing to a long tapering 
cylindrical rostrum, which, in the male, is longer than the carapace and 
only emarginate at the extreme tip, but, in the female, is shorter than 
the carapace and distinctly bifid at the end. 
The carapace is symmetrically honey-combed by deep channels, 
which leave between them great symmetrically undermined islets, as 
follows :—one, very elongate-oval, on the gastric region ; one, triangu¬ 
lar, on the cardiac region; one, somewhat semilunar with one horn 
