COMPLETE HAIG : EASTERN PACIFIC PORCELLANIDAE 67 



Petrolisthes tuber culifrons, Stimpson, 1858, p. 227. 



Petrolisthes tuberculosus, Stimpson, 1858, p. 228. Rathbun, 1910, p. 

 600. 



Petrolisthes affinis, Ortmann, 1897, p. 290. NobiH, 1901a, p. 7; 1902, 

 p. 235. Lenz, 1902, p. 746. Doflein and Balss, 1912, p. 35. Haig, 

 1955, pp. 43, 50, text-fig. 12. Not P. affinis (Gray). 



Previous records: 



Chile. "Chile": (Guerin 1835); (H. Milne Edwards); Favorite 

 (Guerin 1838b); T. Bell (White). Taltal: R. Paessler (Haig). 

 Coquimbo: Nassau (Cunningham) ; L. H. Plate (Lenz). Penin- 

 sula Coquimbo; Bahia Herradura de Guayacan; Montemar: 

 Lund Univ. Chile Exped. (Haig). Valparaiso: (H. Milne Edwards 

 and Lucas); (Nicolet) ; U. S. Expl. Exped. (Dana). Tumbes: 

 L. H. Plate (Lenz). San Vicente: F. Silvestri (Nobili). Bahia 

 de San Vicente: Lund Univ. Chile Exped. (Haig). Chiloe: Nas- 

 sau (Cunningham). 



Coast of South America [probably Chile] : R. Paessler (Doflein 

 and Balss). 



Diagnosis: Carapace with groups of small tubercles anteriorly, 

 rugose posteriorly; no epibranchial spine; front strongly trilobate, 

 median lobe broad, rounded, and concave, lateral lobes narrow and 

 truncate ; carpus about twice as long as wide, anterior margin with two 

 or three strong, uneven, serrate teeth followed by a number of denticles ; 

 merus of walking legs unarmed. 



Description: Carapace with groups of small tubercles anteriorly, 

 rugose on posterolateral regions; surface covered with a fine pubes- 

 cence. Front strongly trilobate, lateral lobes narrow and truncate, median 

 lobe broad, rounded at tip, with a deep concavity flanked on either 

 side by a small tubercle. Outer orbital angle strongly produced into a 

 long, narrow tooth. No epibranchial spine. 



First movable segment of antenna with a low granular crest on 

 anterior margin; second granular; third nearly smooth; flagellum 

 naked, other segments pubescent. Outer maxillipeds nearly smooth or 

 punctate. 



Chelipeds granular, covered with a fine, short pubescence. Merus 

 with a strongly projecting, pointed lobe on anterior margin. Carpus 

 about twice as long as wide ; armed on anterior margin with two or 

 three strong, uneven, serrate-edged teeth, followed by a number of 

 denticles; surface with a strong longitudinal crest, composed of small, 



