852 



U. 8 P. E. R. EXP. AND SURVEYS — ZOOLOGY — GENERAL REPORT. 



at the end; tlie second, tliird, fourth, and fifth also crossed with black towards their ends, decreasing beliind ;oii tlio sixtli a nar" 

 row bar of black; the tips of all white, occupying most space on the si.xlh and lessening in extent to the first, where it becomes a 

 mere edging ; the remaining primaries, the secondaries, and tertiaries terminate largely with white ; the shafts of the tliree outer 

 primaries are blackish brown ; the three lateral tail feathers are white, the others light pearl blue, deepest in color on the two 

 central ones ; bill deep carmine, crossed near the end with black, tip dull yellow ; legs and feet red. 



Lengtii of skin about 13 inches; wing, 11^ ; tail, 4 ; bill, Ij, depth at base C-IG, at angle 5-16 ; tarsus Ij ; middle toe and 

 claw, Ij. 



Young. Differs from the adult in having the forehead grayish white, crown, occiput, and siees of the head blackish browji, 

 the white eye spots as in the adult ; the lesser wing coverts brownish ash, the primaries nmch darker, the inner ones tipped with 

 while ; secondaries and tertiaries witli dark brown centres and ending witli while ; tail crossed with a subtcrminal band of 

 brownish black. 



Length of skin, 131 inches ; wing, 11 ; tail, 4 ; bill, 1^ ; tarsus, l^. 



Httb. — lanama; coast of Louisiana. 



Two specimens are iu the collection ; the adult is in fine plumage, and was obtained in 

 Louisiana by Mr. G. Wurdemann, the first instance of its occurrence within the limits of the 

 United States. This example agreeing so well with Bruch's description of cucullatus, cited above, 

 I have referred it to that species. Mr. Bruch considers L. ptpixcan, Wagler, to be the same as 

 cucullatus, but in Wagler's description nothing is said of the white eye spots, which are a very 

 conspicuous character. 



List of specimens. 



CHROICOCEPHALUS PHILADELPiIIA, Lawrence. 



Bonaparte's Gull. 



Sterna plUladelphia, Onn, Guthrie's Geog. 2d Am. ed. II, 1815, 311). 



Larus capistratus, Bonai'. Syn. 1828, No. 293. 



I.arus bo7iapartei, Rich. &. Sw. F. E. A. II, 1831, 425 ; pi. Ixxii.— Ninr. Man. 11,1834, 294.— Aun. Birds Am. VII, 



1844, 131 ; pi. ccccxiii. 

 CUroicoccpkulus bonaparlei, Bruch, Cab. Jour. 1855, 292. 



Sp. Cii. — ^idult. Head and upper part of neck grayish blr.ck, this color exletnling rather lower on the throat than on the neck 

 behind ; lower part of neck, under jjlumage, rump, and tail white ; hack and wings clear bluish gray ; first primary black on the 

 outer web ; inner web of the first primary , both webs of the second, and the outer web of the third white; the inner web of tho 

 third and all the other primaries are of the same color as the back ; the six outer primaries have their ends black for the extent 

 ofaI)Out an inch on the central ones, but less on the first and sixth, they are all slightly tipped with white ; shoulders, anterior 

 borders of the wings, and outer webs of the primary coverts white ; bill deep black ; inside of mouth carmine ; iris hazel ; legs 

 and feet orange with a reddish tinge. 



Length, 14 j inches ; wing, lOi ; tail, 4] ; bill, 1 i ; tarsus, 1 5-lC. 



}lab. — Texas to Nova Scotia, IVIississippi river, fur countries. Pacific coast of North America. 



The young have the head white, intermixed on the occiput and hind neck with dark gray ; a 

 round spot of dark plumbeous behind the eye ; the smaller wing coverts brown ; the outer webs 

 of several of the primaries and a subterminal band on the tail lilack. 



There are eleven specimens in the collection. 



The specific name of " bonaparlei," under which this species has been so long known, iu my 



