60 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 24 



changes in salinity may enable the species to traverse the Canal on the 

 hulls of ships. 



Range: Mexico (no specific locality reported) south to Guayaquil, 

 Ecuador. 



Petrolisthes hirtipes Lockington 

 Plate 24, fig. 3 



Petrolisthes hirtipes Lockington, 1878, pp. 395, 397 (type localities, 



Bahia Mulege and Puerto Escondido, Gulf of California). A. 



Milne Edwards and Bouvier, 1894, p. 291. Schmitt, 1924b, p. 



383. Glassell, 1936, p. 284; 1938a, p. 443. Steinbeck and Ricketts, 



1941, p. 457, pi. 29, fig. 3. 

 Petrolisthes hispidus, A. Milne Edwards and Bouvier, 1894, p. 293, 



footnote. 



Previous records: 



Baja California. Bahia de la Magdalena: (Glassell 1936). 



Gulf of California. Bahia de Tepoca, Sonora: F. Baker (Schmitt). 

 Puerto Refugio, Isla Angel de la Guarda; Bahia de los Angeles; 

 Bahia de San Carlos: J. Steinbeck and E. F. Ricketts (Steinbeck 

 and Ricketts). Bahia Mulege; Puerto Escondido: (Lockington). 

 Punta Marcial Reef; Bahia San Gabriel, Isla Espiritu Santo: 

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



Lectotype: Ovigerous female, 6.2 mm. in length by 6.4 mm in 

 width, in Paris Museum, labelled '^Petrolisthes hirtipes Lockington. 

 Californie — Lockington 6-99 (Type)." This specimen is hereby desig- 

 nated lectotype at the request of Mr. Jacques Forest. 



Diagnosis: Carapace finely plicate and lightly tuberculate; no epi- 

 branchial spine, but a tubercle or one or two minute spinules some- 

 times present at epibranchial angle; front trilobate; carpus about twice 

 as long as wide, anterior margin with a row of strongly projecting, 

 conical tubercles ; manus with a thick fringe of hair on outer margin ; 

 fingers markedly dissimilar in the two chelipeds; merus of walking 

 legs unarmed on anterior margin (anterodistal angle sometimes spine- 

 tipped), that of legs 1 and 2 spined near distal end of posterior margin. 



Description: Carapace flattened, covered with fine transverse pli- 

 cations, and with a few scattered tubercles anteriorly; surface covered 

 with a short, velvety pubescence, latter forming a fringe on frontal re- 

 gion. Front trilobate, median lobe slightly broader than lateral lobes 



