384 



ORNITHOLOGY. 



monstrated, by future explorers, to be the same in a seasonal plumage 

 not heretofore determined. 



Mr. Peale remarks of this species : 



" Our specimens were obtained, on the 2d September, at Vincennes 

 Island, one of the Paumotu Group. In flight and general appearance 

 this species much resembles the Sooty Tern [Sterna f/iliginosa), but 

 besides the difference of color, is less in size and has a proportionately 

 longer tail." 



We find this bird also mentioned by Dr. Pickering, as seen in large 

 numbers at the locality just given. Specimens in the collection of the 

 Expedition are apparently in fully mature plumage, and are in good 

 preservation. 



3. Sterna poliocerca, Gould. 



Sterna poUocerca , GouLD, Proc. Zool. Soc. London, 1837, p. 26. 



Sterna rectirostris, Peale, Zool. U. S. Exp. Exp. Birds, p. 281 (1848).* 



Gould, B. of Aiist. VII, PI. 24. 



This species, of which the young bird is described by Mr. Peale as 

 above, Avas observed by the naturalists of the Expedition, at the Feejee 

 Islands, especially at Sandalwood Bay, in large numbers. 



We find a single specimen only, in the collection of the Expedition, 

 which is in quite immature plumage, but is apparently Mr. Gould's 

 species as above given, and is quite identical with his specimens now 



* " Neck, breast, and belly, white ; crown, occiput, and back, mottled with brown ; 

 wings and tail, very dark brownish-gray ; bill and legs, obscure bluish-green ; the latter 

 being mottled with brown ; wings white ; beneath, shafts white ; inner webs of the pri- 

 maries black next the shafts, the rest white; outer webs dark gray; secondaries black, 

 margined with white ; outer margin narrowest ; lesser coverts white, slightly tipped with 

 brown ; those along the anterior margins of the wings plumbeous ; scapulars margined 

 with brown ; tail forked, the shafts white ; tips and outer webs, grayish-brown ; inner 

 webs white ; irides brown. 



"Total length, thirteen and one-half inches; wing from the carpal joint, twelve and 

 seven-tenths inches ; tail, four and eight-tenths inches ; middle feathers, two and nine- 

 tenths inches ; bill, one and six-tenths inches ; to the angle of the mouth, two and one- 

 half inches ; tarsi, nineteen-twentieths of an inch ; middle toe, one and two-tenths inches; 

 nail, three-tenths of an inch. Specimen, a young female." 



