300 
PROCEEDINGS OP THE ACADEMY OF 
San Francisco, collected in tliat immediate vicinity, would seem to demon- 
strate the existence of the species on the Pacific as well as on the Atlantic 
coast. The specimens I have compared critically with an eastern series, and 
have been unable to detect the slightest difference. They appear to be abso- 
lutely identical. A circumstance that would seem to confirm the belief that 
the present species does extend quite across the continent is the fact that 
there are' undoubted specimens in the collections of Messrs,., «K,e.nnicott and 
Ross from localities whose general avi-fauna is rather of a western than of an 
eastern type. Should the existence of this bird on the Pacific slope be satis- 
factorily demonstrated, its habitat may properly be given as the “Continent 
of North America.” 
I beg leave to dedicate this species to that Institution whose material for 
the illustration of North American ornithology, unequalled in richness and 
extent, has so greatly increased our knowledge in this department of Natural 
History. And the name seems not inappropriate, for, as there is scarcely a 
lake or river in North America which does not furnish sustenance to this Gull 
at some period of its extensive migrations, so there is hardly a locality, how- 
ever remote or inaccessible, which has not yielded its varied productions to 
the Smithsonian Institution, until its collections afford every facility for the 
study of the Natural History of our Continent. 
II. A large white apical space on first primary in adult birds. Legs dusky 
olivaceous, the webs bright chrome. 
9. Larus Californicus Lawrence. 
L. argentatoides, Bp. 1828 et Richardson, 1831; nec Brehm. L. Cali- 
fornicus , Lawr. 1854 et 1858. Laroides Calif. Bp. 1856. 
Sp. char. — Bill moderately stout and strong, the angle well developed ; 
varying considerably in size, larger than in Delawarensis , sometimes nearly 
equalling argentatus. Tarsus equal to or slightly longer than the middle toe 
and claw. Adult : Bill chrome yellow, tinge with greenish, a vermillion 
spot on the lower mandible at angle ; a black spot just above it, forming wfith 
another small black spot, sometimes present on the upper mandible, an im- 
perfect band. Legs olivaceous greenish or yellowish, the webs chrome. Mantle 
pearl blue, much as in brachyrhynchus, lighter than in canus (Linn.), perhaps a 
little darker than in argentatus. Primaries: bases of all light bluish white, almost 
white internally, especially on the outer ; and of great extent on all the prima- 
ries ; first with a white space at the end about two inches long, the shaft white 
along the white portion of the feather ; second with a white spot near the end. 
on the whole of the inner and most of the outer web, divided by the black 
shaft ; tips of all white ; black forming merely a narrow subterminal band on 
the sixth. Tips of inner primaries, of the secondaries and tertials, white. Di- 
mensions, (average, for they vary greatly) wing 15*50 ; bill nearly 2*00 ; tar- 
sus 2*30. Female smaller. 
Habitat . — California ; Pacific coast ; Arctic America, internally ; breeds 
about Great Slave Lake. 
The following is the argument in favor of the synonymy adduced : 
In the first place, argentatoides of Bonaparte’s Synopsis (1828), and of Rich- 
ardson (1831), are the same bird, since the latter quotes the former as au- 
thority for the name, and the diagnosis and descriptions of the two agree 
perfectly. Now, in the collection there are numerous specimens of the fully 
adult bird from Arctic America, from localities not far distant from those 
where Richardson’s specimens were procured. These specimens agree pre- 
cisely with Richardson’s descriptions of argentatoides ,* and correspond very 
* If it be objected that the expression “ six outer quills crossed by a brownish black 
bar, which takes in nearly the whole of the first one” is not correct, I refer to several 
other descriptions of Richardson, (his canus and others,) where it is evident that he does 
[June* 
