DECAPOD CRUSTACEANS OK THE BEAUFORT, N. C, RJEGION. 423 



lateral lobe; the last posterolateral lobe quite prominent; front usually with a narrow buttonholelike 

 sinus. 



Cheliped short, thick, tuberculate on the outer face and with rough margins; hand stout; thumb 

 thick; movable finger comparatively slender and straight; upper margin of hand with three simple 

 teeth. Walking legs of moderate size, more or less prismatic and lightly grooved. Abdomen narrow, 

 eroded along the margins and on the last two segments. 



Length of a female, 11. 6 mm.; width, 13 mm. 



Two specimens of this ciuious little crab were obtained by the Fish Hawk (station 7959 and 7978) 

 in about 14 fathoms. The species belongs to the West Indian fauna and hitherto has not been collected 

 north of Florida. 



Osachila tuberosa Stimpson. PI. xxxi, fig. 10. 



Osachila tuberosa Stimpson, 18716, p. 154: A. Milne-Edwards, 1880, p. 20 (pt.); Smith, 1886. p. 636 [32]; Rathbun, 1898, p. 

 118; ibid., 1916, p. 649. 



Carapace octagonal with six large protuberances; one mesogastric, one metagastric (paired), one 

 cardiac, one mesobranchial (paired) all of which as well as the lateral margins and, to some extent, 

 the depressions of the shell are eroded; anterolateral margins continued toward the buccal cavity and 

 finely dentate ; posterolateral margins with four lobes, the first of which projects sideways slightly beyond 

 the adjacent anterolateral tooth ; front usually with a narrow sinus. 



Cheliped short, thick, tuberculate on outer face and with rough margins; hand stout; thumb thick, 

 movable finger with a short, dense pubescence; upper margin of hand with three teeth, the proximal 

 one of which is bifid. Walking legs more or less prismatic, with sharp margins and light longitudinal 

 grooves. Abdomen narrow, deeply eroded all over. 



Length of female : 18.2 mm.; width, 20.2 mm.. 



This species has been recorded by Smith (loc. cit.) from off Cape Hatteras in 48 fathoms. Like O. 

 semilevis, it belongs to the West Indian fauna and strays northward along the edge of the Gulf Stream. 



Family LEUCOSIIDAE. 



Oxystomata of normal crablike form having the abdomen hidden beneath the 

 thorax; the antenna small, the legs normal in position, the afferent openings of the gill 

 chambers on either side of the mouth at the base of the third maxillipeds, the gills 

 less than 9 on each side and the male openings sternal. 



Of the 36 genera now placed in this family 4 have representatives in the Beaufort 

 region. 



KEY TO THE GENERA OP THE BEAUFORT REGION. 



o. Carapace ovoid or globular and smooth or granular. 



6. Fingers opening in a horizontal plane Persephona. 



bb. Fingers opening in vertical plane Iliacantha. 



aa. Carapace polygonal, uneven, nodular or eroded. 



b. Posterior portion of carapace without deep cavities Lithadia. 



bb. Posterior portion of carapace with a deep rounded cavity on each side Spelaeophorus. 



Genus PERSEPHONA Leach. 



Persephona Leach, 1817, p. 18, 22. 



Persephona punctata (Linnaeus). Purse crabs. PI. xxxn, fig. 9. 



Cancer punctatus Linnasus, 1758, p. 630 (part.). 



Guaia punctata H. Milne-Edwards, 1S34-1840, t. n, p. 127; Gibbes, 1850, p. 185. 



Persephona punctata Stimpson, 1859, p. 70; Coues, 1871, p. 123; Kingsley, 187S-79, p. 324: Rathbun, 1901, p. 87, 



Carapace globular, thickly strewn dorsally and laterally with granules of various sizes and with 

 three sharp, recurved spines, one at each end of the posterior margin and one median just above the 

 posterior margin; front narrow, broadly bidentate, produced and elevated and with the dentiform angles 

 of the branchial channels projecting slightly beyond it; anterior and lateral regions bounded externally 



