560 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
rectrices white, all except those of three outer pairs, however, olive- 
brown'subterminally. 
Downy young.—Upper parts pinkish buff or light brownish buff 
(more or less deep) fading into buffy 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 male.—Wing, 223-260 (244); tail, 110-122 (117); exposed 
culmen, 37.4-43 (40.2); tarsus, 11.9-13.2 (12.5); middle toe, 20.4- 
22.5 (21.7). 
Adult female.—Wing, 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).2 
More eastern portions of middle Pacific Ocean, from Krusen- 
stern Island, Lisiansky 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 Guetin, 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. 
Syn., ili, 2, 363, no. 17). 
@ 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.), 
Ex- 
Locality. Wing. | Tail. | Posed | Tarsus.| Middle 
men. 
MALES. 
One adult male from Oneal Rock, near Socorro Island (G. a. 
CONMAGI iecccesasaireseeake eucadadameadenseiesadseniemtaan ane 240 115 37.4 12.9]. 20.4 
Three adult males from Clipperton Island (G. a. candida?)..... 236.3 | 117.3 39.2 12.5 21.9 
Six adult males from Cocos Island, Césta Rica (G. a. candida?).| 247.7| 116.5 41,2 12.4 21.8 
Two adult malesfrom Guam, w.-central Pacific(G.a. kittlitzi?)..| 241.5 | 109.5 40.2 13 21.2 
One adult male from Raraka, Paumotu group (G. a. pacifica?).| 251 127 45.5 12.5 21.5 
One adult male from Tahiti, Society group (G. a. pacifica) era aeie 249 103 41.5 12.5 20.5 
One adult male from Dog Island, Pacific Ocean (G@. ¢. ?).| 240 128 40 13 19.5 
One adult male from Aldabra, north of Madagascar (G.a.monte)| 232 110 40.5 12 19.5 
FEMALEs. 
Six adult females from Clipperton Island (G. a. candida?)...... 236.7 | 117.4 38.8 12.2 21.6 
Three adult females from Cocos Island (G. a. candida?)......... 247.3 | 122 40.2 11,9 21.7 
One adult female from 40 miles south of Cocos Island (G. a. 
CONGIAE?) « sixiccrscreyiasrancrsinnisirsenaiarssen giSestesstecininiginiatapeitwavearmiad 245 122 38.9 12.1 22.4 
Two adult females from Laysan (@. a. candida)..........-...-- 238 113.2 37.7 13 21 
One adult female from Guam (G. a. kittlitzi?) ...............2-- 230 112.5 36 1B 22 
One adult female from Aldabra (G. a. monte)............--.5-- 237 111.5 40 12 20 
