COMPLETE HAIG : EASTERN PACIFIC PORCELLANIDAE 113 



Material examined: See Table 34. 



Measurements: Males, 2.6 to 6.7 mm; non-ovigerous females, 3,1 

 to 6.5 mm; ovigerous females, 3.6 to 7.0 mm. A male syntype examined 

 by the writer measures 5.2 mm in length, 4.8 mm in breadth; a fe- 

 male ovigerous syntype, 5.3 by 5.0 mm. 



Color: In alcohol, some specimens show traces of reddish blotches 

 on the carapace and chelipeds. 



Ecology: Petrolisthes ortmanni inhabits the littoral zone, where 

 it has been taken under stones and from coral. The Jskoy recovered 

 it from coral taken from 2 to 3.5 fathoms (Haig, 1957b). 



Ovigerous females have been collected in January, February, 

 March, and April. 



Relationships: Petrolisthes ortmanni is most closely related to P. 

 crenulatus Lockington ; the latter species differs from it chiefly in its 

 larger size, hairier chelipeds and carapace, and more elongate carpus. 



Remarks: Earlier the writer determined (Haig, 1957b) that the 

 two specimens from Isla Flamenco, Panama, reported by Nobili 

 (1901b) as Petrolisthes sp., fall within the normal range of variation 

 of his P. ortmanni. Material studied for the present report extends the 

 range of the species still further in both directions. 



Range: Puerto San Carlos, Gulf of California, south to Islas 

 Lobos de Afuera, Peru ; Islas Las Tres Marias and Isla del Coco, 

 Costa Rica. 



Petrolisthes lewisi lewisi (Glassell) 

 Plate 23, fig. 1 



Pisosoma lewisi Glassell, 1936, p. 287 (type locality, Bahia Tenaca- 

 tita, Mexico). Steinbeck and Ricketts, 1941, p. 458. 



Petrolisthes lewisi, Haig, 1957b, p. 7 (part of synonymy; not new 

 records). 



Previous records: 

 Gulf of California. Punta Lobos, Isla Espiritu Santo : J. Steinbeck and 



E. F. Ricketts (Steinbeck and Ricketts). 

 Mexico. Bahia Tenacatita; Bahia de Tequepa N of Acapulco: F. O. 



l^twh on Stranger (Glassell). 



Diagnosis: Carapace nearly smooth, anterior regions and grooves 

 strongly accentuated ; no epibranchial spine ; front trilobate ; carpus 



