34 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 24 



Petrolisthes edwardsi, Ortmann, 1897, pp. 283, 284. Haig, 1957b, p. 11. 



Petrolistes edwardsii, Nobili, 1901b, p. 11. 



Petrolisthes galathinus, Boone, 1931, p. 155 (part). Not P. galathinus 



(Bosc). 

 Not Petrolisthes edwardsius, Lockington, 1878, pp. 396, 400. 



Previous records: 



Gulf of California. Cabo San Lucas: J. Steinbeck and E. F. Ricketts 

 (Steinbeck and Ricketts). Mazatlan: Verreaux (Saussure). 



Panama. Isia Flamenco: E. Festa (Nobili). Isia Saboga, Islas de las 

 Perlas: Askoy (Haig). Isia del Rey, Islas de las Perlas: W. G. Van 

 Name (Boone 1931). Guayabo Chiquito: Askoy (Haig). 



Colombia. Bahia Utria; Isia Gorgona: Askoy (Haig). 



Ecuador. Isia La Plata: Askoy (Haig). 



Galapagos Islands. Isia Eden off Isia Indefatigable: Williams Gala- 

 pagos Exped. (Schmitt). Off Isia Hood: W. Beebe on A returns 

 (Boone 1932). 



Diagnosis: Carapace with strong, transverse, piliferous striations, 

 not continuing across metabranchial regions, and distinctly interrupted 

 at grooves separating the various regions; a single epibranchial spine; 

 front triangular; carpus about twice as long as wide, anterior margin 

 with three low, wide-set, serrate-edged teeth, and surface with large 

 flattened tubercles; manus with similar but more rounded tubercles; 

 merus of walking legs with a row of spines on anterior margin, that of 

 legs 1 and 2 spined at posterodistal angle. 



Description: Carapace covered with strong, transverse, piliferous 

 striations, interrupted at the grooves separating the various regions, the 

 latter well marked; metabranchial regions without striations, but punc- 

 tate. Front triangular, with a deep median groove extending between 

 protogastric lobes; supraocular spine present or absent, but at least its 

 position clearly marked by a small lobe. Postorbital angle scarcely 

 produced, not spined. A single epibranchial spine. 



First movable segment of antenna with a strongly projecting lamel- 

 lar lobe, granular on its margin and bearing one or two spinules; 

 second granular, with a small conical projection at the distal end of its 

 anterior margin ; third nearly smooth ; flagellum naked. Outer maxilli- 

 peds lightly rugose. 



Merus of chelipeds rugose, with a large serrate-edged tooth on an- 

 terior margin. Carpus about twice as long as wide, armed on anterior 

 margin with three low, wide-set teeth, spine-tipped and denticulate on 



