174 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.24 



broad lobe on anterior margin, edged with large, pointed, conical gran- 

 ules arranged in groups, giving the margin an irregular sawtoothed ap- 

 pearance ; lobe and rest of surface covered with small granules, latter 

 concealed by short, thick-set plumose hairs; two even, longitudinal rows 

 of small pearly tubercles on dorsal surface and a double row along 

 posterior margin, not concealed by this pubescence. Manus and fingers 

 with large coarse granules; a large, strongly projecting granular pro- 

 tuberance at base of pollex; an irregular longitudinal row of smaller 

 protuberances, composed of groups of pointed tubercles, near outer 

 margin of manus and a double row of tubercles along the margin; sur- 

 face of manus covered with short plumose hairs as in carpus, extend- 

 ing onto proximal two-thirds of pollex and inner proximal fourth of 

 dactylus, and not concealing the tubercles and protuberances. Fingers 

 gaping in major cheliped, meeting for entire length in minor cheliped; 

 gape in major cheliped with a thick tuft of plumose hairs, extending 

 along cutting edges of fingers nearly to tips; in minor cheliped, gape 

 with shorter and sparser hairs. 



All segments of walking legs with long plumose hairs; carpus and 

 propodus with short, thick-set, plumose hairs on dorsal surface. 



Telson of abdomen with five plates. A pair of pleopods in male. 



Material exa?nined: See Table 54. 



Measurements: Males, 4.1 to 16.4 mm; non-ovigerous females, 3.9 

 to 12.8 mm; ovigerous females, 4.4 to 15.1 mm. The ovigerous female 

 holotype measures 18 mm in length, 19 mm in width. 



Color: Specimens preserved in alcohol vary in color from dark rust 

 to pale yellow-buff, with the tips of the fingers nearly white. The thick 

 pile covering the chelipeds usually appears black because of the fine 

 silt with which it is filled. 



Ecology: Usually occurring under stones in the intertidal zone. It 

 has also been reported among polychaete tubes and from sponge cavi- 

 ties; it was taken by T. A. Burch in 6 J/2 fathoms from submerged pil- 

 ings at Redondo Beach. 



Ovigerous females were encountered in every month from Novem- 

 ber through March, and in June and July. 



Relationships: Pachycheles rudis Stimpson, which is commonly as- 

 sociated with P. holosericus in the southern part of its range, is closely 

 related to the latter species but may readily be distinguished from it 

 by the much less strongly projecting protuberances and tubercles on the 



