THE GRAPSOID CRABS OF AMEKICA. 29 



Legs slender, simple, fringed with hair, much like those of G. 

 rhomhoides^ but without spine or merus. Abdomen of (? young) 

 male narrow, like that of G. maldivensis Rathbun.^ (After Bor- 

 radaile.) 



Size. — Length of carapace, 13 mm. (Borradaile). 



Locality.— O^ Rio de Janeiro, Brazil; lat. 22° 56' S.; long. 41° 34' 

 W.; 73 meters (40 fathoms) ; May 2, 1913; Terra Nova; 1 male, 1 

 female (Brit. Mus.). 



GONEPLAX TRIDENTATA (A. Milne Edwards). 



Frevillca tridentata A. Milne Edwards, Bull. Mus. Comp. ZoOl., vol. 8, 

 ISSO, p. IG (type-locality, Barbados, " 7i to 50" fathoms, station 287, 

 Blake; holotype in Paris Mus.). 



Diagnosis. — Three lateral teeth. Two spines on wrist. • 



Description. — Antero-lateral teeth 3. "Wrist armed with 2 spines, 

 one inside, the other outside. No tufts of hair on the chelipeds. 

 Dactyli of last pair of feet styliform. 



Dimensions. — Female holotype, length of carapace 5, width of same 

 8 mm. 



Tyjye-locality.—BviYhfxdiOs; lat. 13° 11' 25" N.; long. 59° 38' 20" 

 W. ; 7 fathoms; Co. S. brk. Sh. ; Mar. 8, 1879; station 287; Str. Blake; 

 female holotype in Paris Mus. 



Subfamily Prionoplacinae Alcock. 



Prionoplacinae Alcock, Journ. Asiat. Soc. Bengal, vol, G9, 1900, pp. 286 

 and 292. 



Differs from the Carcinoplacinae in the form of the male abdomen, 

 which is not broad enough at the third segment to cover all the space 

 between the last pair of legs. Some of the genera approach the 

 Goneplacinae in the form of the carapace which, however, does not 

 attain its greatest breadth at the orbital angles. 



Most of the American Goneplacidae are referable to this sub- 

 family. 



Genus PRIONOPLAX Milne Edwards. 



Prionopluw Milne Edwards, Ann. Sci. Nat., ser. 3, Zool., vol. 18, 1852, p. 163 

 [127] ; type, P. spinicarpus Milne Edwards. 



Carapace quadrilateral, transverse, lateral margins converging 

 posteriorly, dentate. Front about one-third width of carapace. The 

 orbits are deep trenches, which occupy the remaining width of the 

 carapace. Eyestalks stout. Antennary flagellum elongate, situated 

 in the orbital hiatus. Antennules transverse. ISIerus of outer maxil- 

 liped much shorter than the ischium, broader than long, antero- 

 external angle prominent, a shallow notch at antero-internal angle. 

 Chelipeds subequal, fingers flattened, pointed. Third segment of 



^Bull. Mus. Conip. Zool., vol. 30, 1902, p. 124. plate, fig. 5. 



