846 



U. S. p. E. B. EXP. AND SURVEYS — ZOOLOGY — GENERAL REPORT. 



LARUS CALIFORNICUS, Lawrence. 



Tlic Coliroinia Gull. 



Larus calijornictis, Lawr. Ann Lye. N. H. N. Y. VI, 1854, 79. 

 Laroides californicus, Bon. Cons. Av. II, 1856, 220. 



Sp. Ch. — .IduU. The head, neck, under plumage, rump, and tail, pure white ; back and wings pearl blue, darker than in 

 L. argcniutus, but not so dark as in L. occidentalis; the six outer primaries are marked with black towards their ends, extending 

 on the first for about two-thirds its length, and becoming less on the others, until on the sixth it consists only of a sub-termina' 

 bar ; the tips of all are while, on the ex erior quill the white extends about two inches, and is crossed near the end by a black 

 bar; the secondaries and tertiaries terminate with white; iiis hazel; bill yellow; basal part of the upper mandible greenish 

 gray for two-thirds its length ; a blackish band crosses both mandibles near their ends, it is darker in color on the lower mandible, 

 where it is bordered with orange ; tarsus and feet flesh color. 



Length, 225 inclies; wing, 16|; tail, 7; bill, 2; depth at angle, 10-16; tarsus, 23 ; middle toe and nail, 3|. 



There are three specimens of this gull in the collection ; one, of which the above are the 

 measurements, differs only from my original specimen in the three outer primaries not having 

 white tips, the first having a white spot near the end, and the tail being marked with an 

 interrupted sub-terminal black band, an evidence that it is not fully adult. 



The two other specimens are smaller, (probably females ;) they appear to be in mature 

 plumage, and have the end of the first primary white for an extent of two inches ; there is a 

 white spot on the second primary about one inch inside of the white tip, in other respects like 

 my specimen. 



They measure in length 20 inches ; wing, 15^- ; tail, 6 ; bill, If ; depth at angle, j\ ; tarsus, 

 2| ; middle toe and nail, 2^. 



Eoh. — West coast of North America. 



Among various specimens of gulls sent me by Professor Baird from his private cabinet for 

 examination, I find two examples of the above species ; these were brought by Dr. Townsend 

 from the Pacific, and were labelled by him L. argentatus. 



List of specimens. 



LARUS DELAWARENSIS, Ord. 



The Ring-billed Gnll. 



Larus dtla\oaremis, Ord, Guth, Geog. 2nd Am. VA. 11, 1815, .319. 



torus conus, BoN. Syn. 1828, No. 2U6 — Kicii. & Sw. F. Bor. Am. II, 1831, 420. 



torus brachyrhtjnclius, Rich. & Sw. F. Bor. Am. II, 1831, 422, (not of Gould.) 



tartis zonorhynchus, Rich. & Sw. F. B. Am. II, 1831, 422 — Nutt. Man. II, 1834, 300.— Add. IJirds Am. VII, 



1844, 152 ; pi. ccccxlvi.— Bon. Cons. Av. II, 1856, 224. 

 Gavina zonorhynchus, Bruch, Cab. Jour. 1855,262. 



