96 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 24 



considerably larger than any specimens seen by the writer and is per- 

 haps an error. 



Color: Dark brownish or bluish black, somewhat lined transversely. 

 (Dana) Reddish-brown, waved and mottled with darker red; paler 

 beneath ; tips of maxillipeds bluish-purple. (Kinahan) 



Ecology: This species usually occurs under stones in the intertidal 

 zone. Kinahan (1857) reported it from a gravelly bottom at a depth of 

 10 fathoms. 



Ovigerous females were taken in January and February by the 

 Velero III, in April or May by the Hassler, and in June and September 

 by the Lund University Chile Expedition. 



Remarks: Guerin (1835) briefly characterized Porcellana granu- 

 losa and P. laevigata from Chile. The only distinction made by him 

 in this and subsequent papers was in the degree of roughness of the 

 carapace, chelipeds, and walking legs, which were said to be granulose 

 in P. granulosa and smooth in P. laevigata. Guerin's (1838b) restric- 

 tion of the type locality of P. granulosa to Paita, Peru, makes it clear 

 that he was dealing with the present species, for the following form does 

 not occur north of central Chile. Since no type locality more specific 

 than "Chile" was given for P. laevigata, the identity of that species 

 cannot be established on a geographical basis. The possibility that 

 Guerin might have applied the name to smooth examples of the present 

 species can be ruled out, however ; three dry specimens from the Guerin 

 collection labelled ^'Porcellana laevigata' and housed in the Academy 

 of Natural Sciences of Philadelphia confirm its identity with the fol- 

 lowing form. One of these specimens is labelled "Type" and the other 

 two "Type" with a query. 



Ortmann (1892) reported several crabs from Golfo de Ancon, 

 Ecuador, among them Petrolisthes granulosus. He later (1897, pp. 279, 

 296) corrected this locality to Ancon, Peru. On the basis of the 1892 

 work Rathbun (1910) included Ecuador in the distribution of Petro- 

 listhes (?) laevigatus ( = that species plus P. granulosus) . 



Ortmann (1897) included Porcellana granulosa and P. striata in 

 the synonymy of Petrolisthes laevigatus. The present writer followed 

 Ortmann, in reporting material in the Hamburg Museum and collected 

 by the Lund University Chile Expedition (Haig, 1955). However, after 

 examination of types and other material, and re-evaluation of char- 

 acters in the light of closely related species, it became evident that 

 Petrolisthes granulosus and P. laevigatus are distinct and valid forms. 



