144 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 24 



The specimens listed under Material Examined, above, plus the 

 holotype and two ovigerous females from the Askoy Expedition, are so 

 far the only known representatives of the species. It is not known 

 whether it is a very rare species or whether its apparent scarcity merely 

 reflects collecting methods. Although most of the material was taken 

 from coral heads, it was not found in abundance as are most porcel- 

 lanid members of the coral community. The closely related Pachy- 

 cheles ackleianus has been taken in quantity from coral heads and 

 sponges dredged in 14 to 37 fathoms; this suggests that P. crassus 

 may normally live under similar conditions. 



Range: Balboa, Panama, south to Isla Gorgona, Colombia. 



Pachycheles biocellatus (Lockington) 



Plate 32, fig. 1 



Petrolisthes (Pisosoma) biocellatus Lockington, 1878, pp. 396, 403 



(type locality, Baja California, exact locality unknown). 

 Petrolisthes (Pisosoma) gibbosicarpus Lockington, 1878, pp. 396, 402 



(type locality, Baja California, exact locality unknown). 

 Pisosoma aphrodita Boone, 1932, p. 53, text-figs. 17-18 (type locality, 



Bahia de Gardner, Isla Hood, Galapagos Islands). 

 Pachycheles biocellatus, Glassell, 1937, p. 84 (neotype designated; neo- 



type locality, off Arena Bank, Gulf of California) ; 1938a, p. 444. 



Schmitt, 1939, pp. 16, 25. Steinbeck and Ricketts, 1941, p. 455. 



Haig, 1957b, p. 4. 



Previous records: 



Gulf of California. "Lower California" [probably Gulf]: (Locking- 

 ton). Off Arena Bank: W. Beebe on Zaca (Glassell 1937). Pulmo 

 Reef: J. Steinbeck and E. F. Ricketts (Steinbeck and Ricketts). 



Clipperton Island: Presidential Cruise of 1938 (Schmitt). 



Colombia. Bahia Humboldt; Isla Gorgona: Askoy (Haig). 



Ecuador. Isla La Plata: Askoy (Haig). 



Galapagos Islands. Bahia de Sulivan, Isla James: Presidential Cruise 

 of 1938 (Schmitt). Bahia de Gardner, Isla Hood: W. Beebe on 

 A returns (Boone). 



Diagnosis: Carapace smooth, devoid of hairs; carpus nearly smooth, 

 anterior margin with a broad lamellar lobe, latter indistinctly to dis- 

 tinctly subdivided into three lobes; manus nearly smooth, outer margin 

 with a smooth crest extending onto pollex and defined by a distinct 

 groove; walking legs covered with long setae; telson five-plated; no 

 pleopods in male. 



