THE SPIDER CBABS OF AMERICA 



79 



Chelipeds longer than the legs, the merus, carpus and upper margin 

 of manus tuberculate. Fingers in adult male two-thirds to three - 

 fourths as long as upper margin of palm, gaping in basal half, deflexed , 

 lower margin of propodal finger convex; dactylus with a large tooth 

 in the gape, fixed finger with a smaller tooth nearer the palm. In the 

 ambulatory legs the carpus and dactylus are more than half as long 

 as the propodus. 



Color. — Tan or gray, with dots and small markings of red; color, 

 however, can not be seen until decorative material is removed. 

 (Way.) 



Measurements. — Male (48833), length of carapace with rostrum 

 65.7, length of rostrum 19, width of carapace 39 mm. 



Range. — From Bering Sea (Nunivak Island and Commander 

 Islands) to Monterey Bay, California, and Honshu Island, Japan. 

 Shallow water to 212 fathoms. 



Material examined. — See table, pages 72-78. 



OREGONIA BIFURCA Rathbnn 



Plates 26 -28 



Oregonia bifurca Rathbun, Proc. U. S. Nat. Mus., vol. 24, 1902, p. 885 

 (type-locality, North of Rat Island, Aleutians, 270 fathoms, station 3785; 

 holotype, Cat. No. 25287, U. S. N. M.); Harriman Alaska Exped., 

 vol. 10, 1904, p. 171, pi. 6, fig. 5. 



Diagnosis. — Rostral horns short, divergent. Supra-orbital arch 

 not prominent nor angled posteriorly. Body sub-oblong. 



DescHption. — Body and appendages covered 

 with soft downy hairs. Carapace wider ante- 

 riorly than in 0. gracilis, the width at base 

 of postorbital spines about two-thirds of the 

 branchial width. Tuberculation finer than in 

 gracilis. Rostrum short, flat, horns divergent 

 from their base, gradually tapering, acuminate. 

 Postorbital spines similar in shape to the rostral 

 horns, but shorter; they are directed more for- 

 ward than in gracilis. 



Basal article of antenna with spinulous outer 

 and inner margins and a stout antero-external 

 spine. Lower margins of arm furnished with 

 stout spines, upper margin with much smaller 

 spines. On the inner surface of the palm are four 

 longitudinal rows of spinules, one just within the 

 upper and the lower margins and one at the middle and below the 

 middle. The fingers are nearly as long as the palm and gape ever so 

 shghtly in their basal two-fifths; at the base of the fixed finger an 



Fig. 21.— Oregonia bifurca, 

 male (46488), abdomen, x 



2.7G 



