PART 1 GARTH : PACIFIC OXYRHYNCHA 273 



Remarkable spinulation is shown by a 4.8 mm young from Redondo 

 Beach, California, with a bifid spine at the outer extremity of the basal 

 antennal article and spinules along both anterior and posterior leg mar- 

 gins, and by a 3.6 mm young from Guadalupe Island, Mexico, in which 

 the spinules extend to the base of the rostrum, the basal antennal article, 

 the postocular cup, and the anterolateral margins, as well as to the cheli- 

 peds and walking legs. This condition, which does not persist in the 

 adult, is contrary to the description of Holmes given above. 



Material examined: 222 specimens from 62 stations. (See Table 55) 

 From Santa Cruz Island, California, and Rocky Point, Gulf of Cali- 

 fornia, Mexico, to Petatlan Bay, Guerrero, Mexico. 



Measurements: Male specimen: length 21.2 mm, width 14.5 mm, 

 rostrum 5.9 mm, width 2.4 mm, cheliped 22.2 mm, chela 11.3 mm, 

 dactyl 5.2 mm, height of palm 4.7 mm, ambulatory legs 28.2, 19.3, 16.2, 

 and 12.6 mm, respectively. Female specimen: length 20.5 mm, width 

 13.0 mm. 



Color in life: Carapace cadmium orange. Chelae white, lightly mot- 

 tled with brown ; fingers brown at base, gradually blending into orange 

 and fading to white on tips. Merus of ambulatory legs strong cadmium 

 orange; carpus, propodus, and dactylus white with a few markings of 

 brown. Ventral side grayish white. (Petersen, of a Gulf of California 

 specimen) 



Habitat: These sluggish creatures live under stones at low tide and 

 usually have their legs closely folded to them. (Nininger) When turned 

 upon its back, will remain motionless with its legs upcurved and is 

 almost indistinguishable from the surroundings. (Johnson and Snook) 

 Almost all specimens are sponge covered, the sponge being either soft 

 fibrous and covering the entire dorsal portion of the carapace and the 

 enlarged meral segments of the legs, or hard and disposed in discrete 

 clumps, as if planted by the crustacean. 



Two specimens from Lower California and the Gulf of California 

 are hosts of rhizocephalan parasites. It is thought that there may be some 

 connection between susceptibility to parasitism in this species and the 

 occurrence of a definitely recognizable form in the male (Pelia clausa) 

 in which the secondary sex character of the enlarged chelipeds fails to 

 develop. More observation is needed to establish this as a fact. 



Depth: Shore to 55 fathoms; possibly to 70 fathoms (Gulf of Cali- 

 fornia). 



Size and sex: From the Hancock series it is apparent that Pelia 

 tumida attains its maximum size in the colder waters off southern Cali- 

 fornia, where males up to 21 mm were encountered. In the Gulf of 



