COMPLETE HAIG : EASTERN PACIFIC PORCELLANIDAE 31 



carpus; outer margin with a row of spines and a fringe of scattered 

 plumose hairs. Fingers with granules similar to those of manus; outer 

 margins of both pollex and dactylus with a row of spines; gape with a 

 short, thick pubescence. 



Walking legs rugose; all segments thickly covered with setae; an- 

 terior margin of merus of leg 1 with five to seven spines, of leg 2 with 

 three to six, of leg 3 with two to four; merus of legs 1 and 2 with a 

 posterodistal spine. 



Ventral surface of chelipeds and walking legs rugose; abdomen 

 smooth to very lightly rugose. 



Material examined: See Table 3. 



Measurements: Males, 3.1 to 11.1 mm; non-ovigerous females, 3.1 

 to 7.9 mm; ovigerous females, 7.6 to 7.9 mm. The male holotype meas- 

 ures 8.7 mm in length, 9.0 mm in breadth. 



Color: Live specimens with a faint pinkish tint; when freshly pre- 

 served in alcohol, beautifully colored with rich reds and purple. (Glas- 

 sell, 1936) 



Ecology: Taken at mean low tide level and below, from among 

 sponges and gorgonians (Glassell). Most of the Velero III and Velero 

 IV specimens were dredged in 3 to 25 fathoms, with recorded bottoms 

 of rock; sand; shell and mud; and mud, sand, and shell. 



Ovigerous females were recovered in March by the Velero III and 

 in June by S. A. Glassell. 



Relationships : This species is not closely related to any of the other 

 eastern Pacific Petrolisthes forms with striated carapace; it is the only 

 one from that area with groups of spines on the carapace surface. 



Remarks: Glassell (1937, p. 82) stated that a bifid-tipped dactylus 

 is characteristic of both this species and Petrolisthes polymitus Glas- 

 sell. In the latter species a single forward-pointing spine is always 

 present near the tip of the dactylus; however, examination of a number 

 of specimens showed that in P. sanfelipensis the row of spines along 

 the outer margin of the dactylus extends to its distal end only in oc- 

 casional individuals. 



Previously recorded only from the northern end of the Gulf of Cali- 

 fornia, Petrolisthes sanfelipensis is now known to occur as far south as 

 Guaymas and also on the west side of the Baja California peninsula. 

 It does not appear to be abundant anywhere. 



