512 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.5 



with ridges of orange red; tips of teeth white. Ambulatory legs apricot 

 orange banded with orange red on merus, carpus, and propodus, and 

 dactylus. Tip of nail white. (Petersen) 



Habitat. — Coarse sand and nullipore ; sand and rock. 



Depth.— 32-2n fms. 



Remarks. — The specimens have been compared with the cotypes from 

 Barbados at Harvard MCZ by Dr. Fenner Chace and with a male and 

 two females taken off Santa Lucia by Captain E. Cole of the Blake in 

 the collections of the U.S. National Museum. Concerning the former 

 comparison Dr. Chace writes: "From the specimens I have seen, both 

 Atlantic and Pacific, I do not believe the latter deserve a specific designa- 

 tion at this time." With this sentiment the writer, in his examination of 

 the Blake specimens, is in perfect agreement. 



E. americanus is now recorded for the first time in Pacific waters. 



Subfamily PlAGUSIINAE 



Genus PLAGUSIA Latreille, 1806 



Plagusia immaculata Lamarck 



Plagusia immaculata Lamarck, Hist. Nat. Anim. sans Vert., vol. 5, p. 

 247, 1818. Rathbun, Bull. 97, U.S. Nat. Mus., p. 335, pi. 103, 1918. 

 Boone, Zoologica, vol. 8, no. 4, p. 264, fig. 95, 1927. 



Type locality. — Mediterranean Sea or Indian Ocean. 



Type. — In Paris Mus. 



Range. — From Punta Arenas, Costa Rica (Biolley), to Taboga 

 Island, Panama (Meek and Hildebrand) ; Galapagos Islands (Arcturus) ; 

 also Indo-Pacific. 



Diagnosis. — Carapace subcircular, depressed, covered with low tu- 

 bercles or squamae, lateral margin toothed. Meri of ambulatory legs with 

 an anterodistal spine, legs conspicuously hairy. 



Material examined. — None from Galapagos Islands. Hancock col- 

 lections contain a series from Cocos Island, Costa Rica. 



Remarks. — ^A pelagic species, the Pacific Log Rider is to be expected 

 whenever the warm Niiio current carries floating rafts southwestward 

 from the Bay of Panama. 



Genus PERGNON Gistel, 1848 



Percnon gibbesi (Milne Edwards) 



Plate 86, Figs. 5, 6 



Acanthopus gibbesi Milne Edwards, Ann. Sci. Nat., ser. 3, Zool., vol. 20, 

 pp. 180 and 146, 1853. 



