REPORT ON THE BRACHYURA. 
237 
its antero-external angle ; the post-abdomen in the male usually much narrower than the 
sternum at the base. 
Genera: — Ocypoda, Fabricius; Gelasimus, Latreille; Acanthoplax, Milne Edwards 
(perhaps to be regarded as a subgenus of Gelasimus)-, Cleistostoma, de Haan ; 
Helcecius, Dana. 
2. Gonoplacinse. 
Gonoplaces canceroides, Milne Edwards (pt.), Ann. d. Sci. Nat., ser. 3, vol. xviii. p. 162, 1852. 
Carapace trapezoidal, with the antero-lateral angles produced and spiniform; the fifth 
joint of the endognath of the exterior maxillipedes articulated with the merus at its 
antero -internal angle ; post-abdomen in the male occupying the whole width of the 
sternum, between the bases of the fifth ambulatory legs. 
Genera : — Gonoplax, Leach, and Ommatocarcinus, White. 1 
3. Macrophthalminse. 
Gonoplaces vigils, Milne Edwards, Ann. d. Sci. Nat., ser. 3, Zool. xviii. p. 155, 1852. 
Macroplithalminx, Dana, XJ.S. Explor. Exped., vol. xiii., Crust., p. 312, 1852. 
Carapace transverse and quadrate, depressed, and clentated behind the antero-lateral 
angles, which are not greatly produced. Front narrow or of moderate width. The 
post-abdomen in the male does not cover the whole width of the sternum at the base, 
between the coxal joints of the fifth ambulatory legs. The fifth joint of the endognath 
of the exterior maxillipedes is articulated with the merus at or near its antero-external 
angle. 
Genera : — Macrophthalmus, Latreille ; Euplax, Milne Edwards ( = Chseno stoma, 
Stimpson, subgenus) ; Hemiplax, Heller; Rhaconotus, Gerstsecker ; Ilyoplax, 
Stimpson. 
Ocypodinte. 
Ocypoda, Fabricius. 
Ocypoda, Fabricius (pt.), Entom. Syst. Suppl. p. 347, 1798. 
,, Milne Edwards, Hist. Nat. Crust., vol. ii. p. 41, 1837; Ann. d. Sci. Nat., ser. 3, 
Zool. xviii. p. 141, 1852. 
,, Kingsley, Proc. Acad. Nat. Sci. Philad., p. 179, 1880. 
„ Miers, Ann. and Mag. Nat. Hist., ser. 5, vol. x. p. 376, 1882. 
Carapace quadrate, moderately transverse and convex, with the dorsal surface closely 
granulated, the lateral margins entire, the cervical and cardiaco-branchial sutures in part 
1 The genus Prionopla x, Milne Edwards, which that author arranges with these genera, is, I think, better placed in 
the family Carcinoplacidae ; it is intermediate in structure between Pseudorhombila and Macrophthalmus. 
