COMPLETE HAIG : EASTERN PACIFIC PORCELLANDDAE 35 



their margins ; anterior margin usually with a few smaller denticles be- 

 tween these teeth; surface with large, flattened tubercles, median ones 

 largest and forming an irregular longitudinal row; some of those along 

 posterior margin produced into spines, and posterodistal angle with a 

 long spine-tipped extension. Manus broad, flattened, covered with tu- 

 bercles similar to those of carpus, but usually more rounded; 

 a few of the proximal ones along outer margin usually produced into 

 spines. Fingers with tubercles similar to those of manus; gape with a 

 short, thick pubescence, confined to dactylus and extending nearly to 

 tip of latter. 



Walking legs with small, flattened tubercles; anterior margin of 

 merus and carpus with a fringe of plumose hairs, all segments covered 

 with long, non-plumose setae; anterior margin of merus of leg 1 with 

 nine to eleven spines, of leg 2 with ten to twelve, of leg 3 with five to 

 eleven; one or two (rarely three) posterodistal spines on merus of legs 

 1 and 2. 



Ventral surface of chelipeds and walking legs, and abdomen, with- 

 out distinct striations. 



Material examined: See Table 5. 



Measurements: Males, 3.8 to 15.9 mm; non-ovigerous females, 3.3 

 to 12.3 mm; ovigerous females, 4.7 to 14.7 mm. Measurements of the 

 type were given as 7 by 7 lines (about 16 mm). 



Color: In alcohol the striations of the carapace show red stripes, 

 which may be broken up into spots. The tubercles of the chelipeds are 

 red, the carpus and propodus of the walking legs are broadly striped 

 with red, and the abdomen is spotted. The palp of the outer maxillipeds 

 is bright blue. 



Ecology: Petrolisthes edwardsii occurs in the intertidal zone under 

 stones, and in coral heads to a depth of about 6 fathoms. It has also 

 been dredged in depths to about 20 fathoms; the Vetera III took it on 

 hard substrates such as sand and shell, gravel, corallines, rock, and nul- 

 lipores. Hancock Foundation collectors recovered it on one occasion 

 from a sponge dredged by the Velero IV in 1-4 fathoms. A specimen in 

 the Hancock Foundation collections was taken from the stomach of a 

 tuna, Neothunnus macropterus, captured off Mazatlan, Gulf of Cali- 

 fornia. 



Ovigerous females have been collected in every month from Decem- 

 ber through May, and in September. 



