THE GBAPSOID CKABS OF AMERICA. 365 



Legs strongly dentate along the last three joints; 6 rows of spines 

 on the dactyli. 



Color. — Brownish-red. 



Ilahitat. — Lives in moist land or mud. Migrates to the sea during 

 the rainy season to hatch the eggs. Vast quantities of the megalopa- 

 larva have been found in the sea shortly after migration; also, at a 

 later date, the young crab.^ 



Measurements. — Male type (according to the figure), length of 

 carapace 61, width of same 8G.5 mm. 



Range. — Brazil (Milne Edwards) ; South America (White, Brit. 

 Mus.). Both these localities are doubtful. It is likely that the 

 species inhabits only Indo-Pacific Islands. 



Family OCYPODIDAE Ortmann. 



Ocypodicns jriLNE Edwards, Hist. Nat. Crust, vol, 2, 1837, p. 39, 

 Ocypodiuw Milne Edwabds, Ann. Scl. Nat, ser. 3, Zool., vol. IS, 1S52, p. 



140 ri04] (part). 

 Alactophthuhnidw Dana, U. S. Expl. Exped., vol. 13, Crust, pt 1, 1852, 



pp. 308 iiiKl 312. 

 Ocypodidw Oktmann, Zool. Jahrb., Syst., vol. 7, 1894, pp. 700 and 741. — 



Alcock, Journ. Asiat. Soc. Bengal, vol. G9, 1900. pp. 283, 290, and 294. 



Palp of external maxillipeds coarse, articulating at or near the 

 antero-external angle of the merus; exognath generally slender and 

 often more or less concealed. Front usually of no great breadth and 

 often a narrow lobe more or less deflexed. The orbits occupy the 

 whole anterior border of the carapace outside the front, and their 

 outer wall is often defective. 



Buccal cavern usually large and a little narrower in front than 

 behind, the external maxillipeds often, but not always, completely 

 close it. Abdomen of male narrow. Male openings sternal. 



Amphibious littoral and estuarine crabs, burrowing and commonly 

 gregarious. 



KEt TO THE AMERICAN SUBFAMILIES AND GENERA OB" THE FAMILY OCTPODIDAE. 



\*. An orifice or recess, the edge of which is thickly fringed with hair, hetween 

 the bases of the second and third pali-s of ambulatory legs, Anteniudar 

 flagella small or rudimentary, folding obliquely or almost vertically, the 

 interantennular septum broad. Chelipeds very unequal either in both 



sexes or in the male only Subfamily Ocripodinae, p. SOG. 



B\ Antennular flagella rudimentary, completely hidden beneath the front; 

 antennae small, almost rudimentary. Eyes very large, occupying the 

 greater part of the ventral surface of the eyestalks. Chelipeds very 

 unequal in both sexes Oci/pode, p, 3GG. 



* See Andrews, Monogr. Cbriistmas Island, 1900, p. 163. 



