COMPLETE HAIG : EASTERN PACIFIC PORCELLANIDAE 39 



A survey of unreported collections, chiefly from the U. S. National 

 Museum, revealed many more Pacific records for Petrolisthes gala- 

 thinus. On the Atlantic coast this species is very common and ranges 

 from Cape Hatteras, North Carolina, to Rio de Janeiro, Brazil, through- 

 out the Caribbean area, and on the Brazilian island of Ilha Trindade, 

 about 700 miles from the mainland. In the Pacific, on the other hand, 

 nearly all the known specimens have come from a relatively small area 

 in the vicinity of Panama City. Despite extensive collecting along the 

 Pacific coast over a period of many years, the only known examples 

 of P. galathinus from outside this area are three specimens from Isla 

 San Lucas, Costa Rica, collected in 1930, and three taken off La 

 Libertad, Eduador, in 1933. It seems strange that the species has ap- 

 parently remained almost entirely concentrated in a very limited area 

 in the Pacific, particularly since it is unusually wide-ranging on the 

 Atlantic coast. 



Petrolisthes glasselli Haig 

 Plate 20, fig. 2 



Petrolisthes amoenus, Boone, 1932, p. 41, text-figs. 11-12. Not P. 



amoenus (Guerin). 

 Petrolisthes glasselli Haig, 1957a, p. 33, pi. 8, figs. 1-3 (type locality, 



Bahia Octavia, Colombia) ; 1957b, p. 13. 



Previous records: 

 Mexico. Islas Las Tres Marias: (Haig 1957a). 

 Panama. Isla Saboga, Islas de las Perlas: Askoy (Haig 1957b). 

 Colombia. Bahia Octavia: Velero III (Haig 1957a). Isla Gorgona: 



Askoy (Haig 1957b). 

 Galapagos Islands. Bahia de Gardner, Isla Hood: W. Beebe on 



Arcturus (Boone). 



Diagnosis: Carapace with distinct, transverse, piliferous striations, 

 not continuing across metabranchial regions; two epibranchial spines; 

 front triangular ; carpus less than twice as long as wide, anterior margin 

 with four or five broad, serrate-edged teeth, and surface with oblique 

 striations; manus with oblique striations; merus of walking legs with 

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

 posterodistal angle. 



Description: Carapace covered with distinct, transverse, piliferous 

 striations, interrupted at cervical and branchial grooves; frontal region 

 granulate and metabranchial regions punctate, these regions lacking 



