852 
U. S P. E. R. EXP. AND SURVEYS — ZOOLOGY GENERAL REPORT. 
at the end; the second, third, fourth, and fifth also crossed with black towards their ends, decreasing behind ; on the sixth a nar- 
row bar of black; the tips of all white, occupying most space on the sixth 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 three 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. 
Length of skin about 13 inches ; wing, 11^ ; tail, 4 ; bill, lj, depth at base 6-16, at angle 5-16 ; tarsus H ; middle toe and 
claw, lj. 
Young. Differs from the adult in having the forehead grayish white, crown, occiput, and sioes of the head blackish brown, 
the white eye spots as in the adult ; the lesser wing coverts brownish ash, the primaries much darker, the inner ones tipped with 
white ; secondaries and tertiaries with dark brown centres and ending with white ; tail crossed with a subterminal band of 
brownish black. 
Length of skin, 13| inches ; wing, 11 ; tail, 4; bill, 1| ; tarsus, 1|. 
Hab. — Panama; coast, of Louisiana. 
Two specimens are in 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. pipixcan, 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. 
Catal. 
No. 
Sex k 
Age. 
Locality. 
When collected. 
Whence obtained. 
Point of bill to 
end of tail. 
Wing from 
carpal joint. 
4320 
4522 
o 
Calcasieu Pass, Louisiana - 
1854 
Dec. 28, 1855. 
G. Wurdemann 
Dr. Suckley 
13. 00 
13. 50 
11. 12 
11. 00 
CHROICOCEPHALUS PHILADELPHIA, Lawrence. 
Bonaparte's Gull. 
Sttma Philadelphia, Ord, Guthrie's Geog. 2d Am. ed. II, 1815, 319. 
Larus capislratus, Bonap. Syn. 1828, No. 293. 
Larus bonapartei, Rich. & Sw. F. B. A. II, 1831, 425 ; pi. Ixxii.— Nutt. Man. II, 1834, 291.— Aud. Birds Am. VII, 
1844, 131 ; pi. ccccxlii. 
Chroicocephalus bonapartei, Bruch, Cab. Jour. 1855, 292. 
Sp. Ch. — Adult. Head and upper part of neck grayish blr.ck, this color extending rather lower on the throat than on the neck 
behind ; lower part of neck, under plumage, rump, and tail white ; back 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 the 
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 
of about 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± inches ; wing, 10| ; tail, 4;} ; bill, 1| ; tarsus, 1 5-16. 
Hub- — Texas to Nova Scotia, Mississippi 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 black. 
There are eleven specimens in the collection. 
The specific name of " bonapartei/' under which this species has been so long known, in my 
