560 



BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



rectrices wliite, all except those of tlii*ee outer pairs, however, olive- 

 browii siibterminally. 



Downy young. — Upper parts pinkish buff or light brownish buff 

 (more or less deep) fading into bufty whitish on forehead, super- 

 ciliary region, and under parts; a postocular streak or elongated 

 spot of black, and on occiput a median transverse spot or bar and 

 two lateral spots (one on each side) of black. 



Adult ma^e.— Wing, 223-260 (244); tail, 110-122 (117); exposed 

 cuhnen, 37.4-43 (40.2); tarsus, 11.9-13.2 (12.5); middle toe, 20.4- 

 22.5 (21.7).« 



Adult female.— Wm.g, 231-254 (241); tail, 107-129 (119); exposed 

 culmen, 36.7-41.6 (39.2); tarsus, 11.1-12.8 (12); middle toe, 21-22.4 

 (21.7).° 



More eastern portions of middle Pacific Ocean, from Krusen- 

 stern Island, Lisiansk}^ Island, Laysan, Necker Island, and Christ- 

 mas Island eastward to Revillagigedo Islands (Oneal Rock, near 

 Socorro Island), Clipperton Island, Cocos Island, and Galapagos 

 Archipelago (Tower Island). 



[Sterna] Candida Gmelin, Syst. Nat., i, pt. ii, 1789, 607 (Christmas Island and other 

 parts of the South Seas, seen also in St. Helena; founded on Latham, Gen. 

 Sj-n., iii, 2, 363, no. 17). 



a Ten specimens from Clipperton and Cocos Islands, 40 miles south of Cocos Island 

 and Oneal Rock, near Socorro Island. (Measurements from Gifford, Proc. Calif. 

 Acad. Sci., 4th ser., ii, 1913 34.), 



