THE CANCROID CRABS OF AMERICA 255 



ACTAEA BIFRONS Rathban 



Plate 104, Figures 3-6 



Actaea bifrons Rathbun, Bull. Lab. Nat. Hist. State Univ. Iowa, vol. 4, 1898, 

 p. 262, pi. 4, figs. 3 and 4 (type-locality, off Aspinwall [Colon], 34 fathoms; type, 

 Cat. No. 7803, U.S.N.M.); Bull. U. S. Fish Comm., vol. 20 for 1900, pt. 2 

 (1901), p. 34. — Odhner, Goteborg's K. Vet. Handl., Fjarde Foljden, vol. 

 29, No. 1, 1925, p. 50, pi. 3, figs. 12 and 12a. 



Diagnosis. — Carapace flattish, granulation sparse anteriorly; front 

 steeply inclined; palm concealed by long thick hair; fingers long, 

 smooth and punctate, not channeled. 



Description. — Compared to A. setigera, carapace narrower and 

 flatter, areolations similar, but epigastric and postfrontal lobes sharply 

 set off, sparsely granulate, marginal lobes more angular. Single hairs 

 on carapace especially on side margins; like the remaining hairs, they 

 are weak and colorless, not stiff and yellow as in setigera. Frontal 



FiGUEE 41.— Actaea BIFRONS, MALE. a. Dorsal VIEW, X3.2. 6. Fkont,X6.4 



lobes bent abruptly down, margins little advanced. Eyes larger; 

 tooth at lower inner angle of orbit prominent. Chelipeds differ from 

 those of setigera in the fingers longer in proportion to the palm, more 

 strongly bent downward, and smooth, not channeled but with two 

 rows of punctae on outer surface; in the immovable finger wider at 

 base than the movable; in the granules of wrist and hand nearly 

 concealed by thick hairy covering. Ambulatory legs tolerably hairy, 

 especially the dactyls. 



Color. — Carapace above reddish orange; fingers faded brownish 

 black (Henderson). 



Measurements. — Ovigerous female (53769), total length of cara- 

 pace 7, width 10.5 mm. Female, Spanish Water, length of carapace 

 10.5, width 15.2 mm. 



Range. — Florida Keys to north coast of South America. To a 

 depth of 40 fathoms. 



Material examined. — Western Dry Rocks, Key West, Florida; 25 

 fathoms; J. B. Henderson; 1 ovigerous female (53769). 



