COMPLETE HAIG: EASTERN PACIFIC PORCELLANIDAE 117 



found to belong to P. lewisi austrinus. Specimens from the Askoy 

 Expedition referred by the writer (Haig, 1957b) to P. lewisi Glassell 

 have since been re-examined. A portion of those from Guayabo Chi- 

 quito, Panama, are now placed in the new subspecies, while the rest 

 of the Guayabo Chiquito material, as well as that from Golfo de Cu- 

 pica, Colombia, is referred to Petrolisthes artifrons, new species. 

 The subspecific name is from the Latin austrinus, southern. 



Range: Bahia de Salinas, Costa Rica, south to Punta Santa 

 Elena, Ecuador. 



Petrolisthes cocoensis, new species 

 Plate 6 ; plate 22, fig. 2 



Types: Holotype, male, U. S. National Museum Cat. No. 102408, 

 from Bahia de Wafer, Isla del Coco, Costa Rica, rocky shore; 

 March 2, 1933; collected during Allan Hancock Pacific Expedition of 

 1933 at Velero III station 107-33. Paratypes: same data as holotype, 

 two males, seven ovigerous females (U. S. National Museum) ; two 

 males, four ovigerous females (Allan Hancock Foundation). Paratypes: 

 Bahia de Chatham, Isla del Coco, Costa Rica, shore; January 14, 1938; 

 collected at Velero III station 778-38 ; one ovigerous female. 



Diagnosis: Carapace nearly smooth, anterior regions and grooves 

 strongly accentuated ; no epibranchial spine ; front broadly triangular or 

 rounded in dorsal view, strongly deflexed ; orbits very shallow, in dorsal 

 view forming a nearly straight line with front ; carpus about one and a 

 half times as long as wide, anterior margin with a strong, broad lobe; 

 manus with two strong dorsal crests and a third along outer margin, 

 these crests defined by broad grooves; merus of walking legs unarmed. 



Description: Carapace subovate or subquadrate, margins parallel 

 posterior to epibranchial regions; nearly smooth, lightly plicate on post- 

 erolateral regions and punctate anteriorly. Frontal groove and grooves 

 defining protogastric and hepatic regions strongly accentuated. Front 

 broad, strongly deflexed ; broadly triangular or somewhat rounded in 

 dorsal view, in frontal view trilobate, the lobes rounded, about equal 

 in breadth, median one more projecting. Orbits very shallow, in dorsal 

 view forming a nearly straight line with front, latter somewhat resem- 

 bling that of Petrolisthes violaceus (Guerin) ; outer orbital angle not 

 produced. Epibranchial region projecting at a distinct, obtuse angle to 

 hepatic region; no epibranchial spine. Carapace with traces of hairs 

 anteriorly. 



