male one cheliped is enormously enlarged, and the other very small, 



as are both chelipeds in the female Uca. p. 374. 



A 1 . No special recess between the bases of any of the legs. Antennular flagella 

 well developed, folding transversely, the interantennular septum very 

 narrow. Chelipeds usually subequal__Subfaimly Macrophthalminac, p. 423. 



Euplax, p. 423. 



Subfamily OCYPODINAE Dana. 



Ocypodiacgs ordinaire* MILNE EDWARDS, Ann. Sci. Nat., Zool., ser. 3, vol. 18, 



1852, p. 140 [104]. 

 Ocypodlnce DANA, Amer. Journ. Sci., ser. 2, vol. 12, 1851, p. 286 ; U. S. Expl. 



Exped., vol. 13, Crust., vol. 1, 1852, p. 312 (part). ALCOCK, Journ. 



Asiat. Soc. Bengal, vol. 69, 1900, p. 290. 



Carapace deep, subquadrilateral, the regions seldom well defined; 

 front narrow, deflexed. commonly a mere lobe between the long eye- 

 stalks ; antemmlar flagellum small, folding obliquely or almost verti- 

 cally, the interantennular septum broad; the external maxillipeds 

 completely close the buccal cavern, their exognath is inconspicuous 

 but is not, or not entirely, concealed, and may either have, or be desti- 

 tute of, a flagellum; chelipeds remarkably unequal either in both 

 sexes or in the male only. There is an orifice or recess, the edge of 

 which is thickly fringed with hair, between the bases of the second 

 and third pairs of true legs. 1 



Genus OCYPODE Fabricius. 



Ocypode FABRICIUS, Entom. Syst., Suppl., 1798, p. 312; type, 0. ceratoph- 

 thalma (Pallas). 



Monolepis SAY, Journ. Acad. Nat. Sci. Philadelphia, vol. 1, 1817, p. 155; 

 type. M. inermis Say, larval stage of O. albicans Bosc. 



Ceratophthalma MACLEAY, Zool. S. Africa, Annul., 1838, p. 64; type C. 

 cursor (Herbst, 1782) ceratophthalma (Pallas, 1772). 



Parocypoda NEUMANN, Cat. Podoph. Crust. Heidelberger Mus., 1878, p. 26; 

 type, P. ceratophthalma (Pallas). 



Carapace deep, subquadrilateral, somewhat broader than long, 

 moderately convex, strongly declivous anteriorly, dorsal surface 

 closely granular, regions indistinctly and incompletely defined. 

 Front a narrow deflexed lobe, from one-seventh to one-ninth the 

 greatest breadth of the carapace. 



Orbits large, divided into 2 chambers. The eye occupies the 

 ventral surface of the eyestalk and is often prolonged in a horn 

 or style. 



Only the basal joint of the antennulae is visible; antennae small 

 and rudimentary. 



1 For a description of this connection with the branchial cavity, see Fritz Miiller'a 

 Facts and Arguments for Darwin, translated by W. S. Dallas, London, 1869, pp. 33-36. 



