REPORT ON THE BRACHYURA. 
241 
Gelcisimus, Latreille. 
Gelasimus, Latreille, Nouv. Diet. cl. Hist. Nat., ed. 2, vol. xviii. p. 286, 1880. 
,, Milne Edwards, Hist. Nat. Crust., vol. ii. p. 49, 1837; Ann. d. Sci. Nat., ser. 3, 
vol. xviii. p. 144, 1852. 
„ Kingsley, Proc. Acad. Nat. Sci. PhilacL, p. 135, 1880. 
Carapace transverse, longitudinally convex, usually smooth on the dorsal surface, but 
sometimes granulated, with the cervical and cardiaco-branchial sutures usually more 
or less distinctly defined, with the antero-lateral angles usually prominent and acute, and 
the lateral margins nearly straight, and convergent to the posterior margin. The front 
is cleflexed, usually very narrow, almost linear between the bases of the eye-peduncles, 
but sometimes much broader, and at the base nearly equalling one-third the width of the 
carapace at the anterior margin. The orbits are very large and, as in Macroplithalmus, 
extend along the whole anterior surface of the carapace, between the front and antero- 
lateral margins. The longitudinal ridges of the endostome are usually more or less 
distinctly developed. The post-abdomen in the male is narrow and distinctly seven- 
jointed, and its base does not occupy the whole width of the sternum between the bases 
of the ambulatory legs. The eye-peduncles (as in Macroplithalmus) are very slender and 
elongated, reaching, or nearly reaching, the antero-lateral angles of the carapace. The 
antennulary flagella are usually somewhat obliquely plicated. The basal joint of the 
antennse is small, and placed beneath the bases of the eye-peduncles ; the flagella are of 
moderate length. The ischium of the exterior maxillipecles is much larger than the 
merus, and is not produced at its antero-internal angle ; the merus is small, usually 
transverse, distally truncated, and not emarginated at the antero-internal angle, and the 
following joint is articulated at the antero-external angle of the merus. The chelipedes are 
very unequally developed, either the right or left may be the larger in the same species ; 
the merus in the larger chelipede is usually trigonous and prolonged beyond the antero- 
lateral angles of the carapace ; the carpus is moderately elongated, and has usually no 
spine on its interior surface; the hand is compressed and enormously developed, usually 
greatly exceeding in length the three preceding joints; the palm is much shorter than 
the fingers, and is usually obliquely cristatecl on the inner surface ; the fingers are 
distally acute or subacute, granulated, and usually lobated on the inner margins ; in the 
smaller chelipede (and in both chelipedes in the female) the joints are slender and feeble. 
The ambulatory legs are of moderate length and present nothing remarkable ; the merus- 
joints are compressed, and the dactyli styliform. 
The described species are extremely numerous, and occur in all the warmer temperate, 
subtropical, and tropical regions of the globe. The two which are mentioned below have 
been described since the publication of Mr. Kingsley’s list. 
Gelasimus thomsoni, Kirk. New Zealand (Wellington). 
Gelasimus cimatodus, Rochebrune. Senegambia. 
(ZOOL. CHALL. EXP. — PART XLIX. 1886.) 
Ccc 31 
