COMPLETE HAIG : EASTERN PACIFIC PORCELLANIDAE 41 



Ovlgerous females have been collected in every month from January 

 through May. 



Relationships: This species is closely related to Petrolisthes gala- 

 thinus (Bosc), but is easily distinguished from the latter form by the 

 absence of any pubescence in the gape of the fingers, and the presence 

 of two marginal epibranchial spines. 



Remarks: Petrolisthes glasselli was first reported by Boone (1932), 

 who identified it as Petrolisthes amoenus (Guerin), 1855, an Atlantic 

 form. Boone's description and accompanying illustration leave no 

 doubt that her specimens should be referred to the present species. 



In the original description of the species, the holotype was inad- 

 vertently given an Allan Hancock Foundation catalog number. This type 

 is housed in the U. S. National Museum where it bears catalog num- 

 ber 102402. 



Range: Cabo San Lucas at the mouth of the Gulf of California, 

 south to Isla Gorgona, Colombia; Isabel, Tres Marias, Revillagigedo, 

 and Galapagos Islands. Shore to 4 fathoms. 



Petrolisthes polymitus Glassell 

 Plate 22, fig. 1 

 Petrolisthes polymitus Glassell, 1937, p. 81, pi. 1, fig. 1 (type local- 

 ity, off Arena Bank, Gulf of California) ; 1938a, p. 443. 



Previous records: Gulf of California. Off Arena Bank: W. Beebe 

 on Zaca (Glassell 1937). 



Diagnosis: Carapace with distinct, transverse, piliferous striations, 

 continuing across metabranchial regions; a single epibranchial spine; 

 front broad, sinuously triangular; carpus about one and a half times as 

 long as wide, anterior margin with four or five broad, serrate-edged 

 teeth, and surface with short flattened rugae ; manus with similar rugae 

 and large flattened granules; merus of walking legs with one or two 

 distal spines on anterior margin, that of leg 1 spined at posterodistal 

 angle. 



Description: Carapace covered with distinct, transverse, piliferous 

 striations, not interrupted at grooves separating the various regions, 

 latter not distinct; absent only on frontal region, this area granulate. 

 Front broadly, sinuously triangular, its margin minutely denticulate, 

 and with a median sulcus extending between protogastric lobes ; a small 

 supraocular spine. Postorbital angle scarcely produced. A single epi- 

 branchial spine. 



