30 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 24 



Petrolisthes sanfelipensis Glassell 



Plate 20, fig. 3 



Petrolisthes sanfelipensis Glassell, 1936, p. 281 (type locality, San 



Felipe, Gulf of California) ; 1938a, p. 443. 

 Petrolisthes felipensis, Glassell, 1937, p. 82. 



Previous records: Gulf of California. Punta Penasco, Sonera; San 

 Felipe: S. A. Glassell (Glassell 1936). 



Diagnosis: Carapace with distinct, transverse, piliferous striations, 

 not continuing across metabranchial regions; groups of spines on hep- 

 atic, protogastric, and epibranchial regions, and a row of marginal 

 mesobranchial spines, in addition to the usual epibranchial spine; front 

 triangular, denticulate on margin; carpus about twice as long as wide 

 (longer in some large specimens), anterior margin with three or four 

 low, wide-set, serrate-edged teeth, and surface with short, rough rugae 

 sometimes produced into spinules; merus of walking legs with a row 

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

 distal angle. 



Description: Carapace covered with distinct, transverse, piliferous 

 striations, scarcely interrupted at grooves separating the various re- 

 gions, latter distinct; striations absent only on metabranchial regions, 

 latter areas nearly smooth. Front triangular, denticulate on margin, 

 with a deep median groove extending between protogastric lobes; a 

 distinct supraocular spine, and a row of denticles on orbital margin. 

 Postorbital angle with a strong spine. Upper surface of carapace with 

 groups of spines on hepatic, protogastric, and epibranchial regions, 

 partially obsolescent in large specimens; margins with an epibranchial 

 spine and a row of mesobranchial spines. 



First movable segment of antenna with a strong lamellar lobe, bear- 

 ing a row of spinules; second with two spinules; third nearly smooth; 

 flagellum naked. Outer maxillipeds rugose. 



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

 terior margin. Carpus about twice as long as wide, longer in some 

 large specimens; armed on anterior margin with three or four low, 

 wide-set teeth, denticulate on their margins, some of them often semi- 

 divided into smaller teeth; surface with short, rough rugae, granulate 

 on their margins and often produced in the form of spinules, those 

 rugae along center more elongate and forming a low longitudinal crest; 

 posterior margin with a row of spines. Manus long and slender, covered 

 with small groups of rough granules, often produced into spinules as in 



