COMPLETE HAIG : EASTERN PACIFIC PORCELLANIDAE 43 



Remarks: Formerly known from a single specimen taken in the 

 southern part of the Gulf of California, Petrolisthes polymitus is now 

 shown to extend along the mainland as far south as Ecuador and also 

 to be common in the Galapagos Islands. 



Range: Isla Espiritu Santo, Gulf of California, south to La Lib- 

 ertad, Ecuador; Tres Marias and Galapagos Islands. Shore to 4 

 fathoms. 



Petrolisthes desmarestii (Guerin) 

 Plate 19, fig. 3 



Porcellana desmarestii Guerin, 1835, p. 115 (type locality, Chile); 

 1838b, p. 7, pi. VII 26, fig. 1 (type locality restricted to Val- 

 paraiso) ; 1839, p. 175, pi. 52, fig. 1. Nicolet, 1849, p. 198. Not 

 White, 1847, p. 62. 



Porcellana acanthophora H. Milne Edwards and Lucas, 1844, p. 33, pi. 

 16, fig. 2 (type locality, Valparaiso, Chile). Nicolet, 1849, p. 196. 



Porcellana dubia Kinahan, 1857, p. 348, pi. 14, fig. 4 (type locality, 

 Callao, Peru). 



Petrolisthes acanthophorus, Stimpson, 1858, p. 228. Cano, 1889, pp. 

 96, 100, 258. Rathbun, 1910, p. 600. Porter, 1925, p. 320; 1936b, 

 p. 153; 1936c, p. 339. Haig, 1955, p. 54, text-fig. 13. 



[Petrolisthesi desmarestii?, Stimpson, 1858, p. 228. 



Petrolisthes (?) desmarestii, Rathbun, 1910, p. 600. 



Petrolisthes desmaresti, Haig, 1955, p. 54. 



Previous records: 



Peru. Callao: J. R. Kinahan (Kinahan) ; Vettor Pisani (Cano). 



Chile. "Chile": (Guerin 1835). Pisagua; Iquique; Coloso near Anto- 

 fagasta: R. Paessler (Haig). Bahia de Taltal: A. Capdeville 

 (Porter 1925). Taltal: R. Paessler (Haig). Valparaiso: Favorite 

 (Guerin 1838b) ; A. d'Orbigny (H. Milne Edwards and Lucas). 

 Bahia de Talcahuano: (Porter 1936b, 1936c). Coronel: R. Paess- 

 ler (Haig). 



W coast of South America [probably Chile] : Rehberg (Haig). 



Diagnosis: Carapace covered with fine plications; a single epi- 

 branchial spine; front triangular; carpus about twice as long as wide, 

 anterior margin with four or five broad, serrate-edged teeth; manus 

 covered with small flattened tubercles; merus of walking legs with a 

 row of spines on anterior margin, that of legs 1 and 2 spined at postero- 

 distal angle. 



