NATURAL SCIENCES OE PHILADELPHIA. 
299 
mg the claims of these markings to be considered as of value. The radical 
difference still exists. 
But if then the terminal marking of the primaries of californicus are like 
those of the European argentatus , and the two species are nearly identical in 
size and general robustness, what are the differences between these two 
species ? Briefly as follows : The European argentatus, though less robust 
than the does not exhibit that decided approach to the “j/ew gull ” 
type indicated in the californicus by its greenish legs. Though the terminal 
markings of the primaries are quite identical, the character of the bluish bases 
differ decidedly. In californicus this color is very light, so much so as to be 
almost white. It runs up further on the primaries (especially on the first), 
and with a different pattern, its edge being nearly parallel with the shaft for 
the greater part of its length, and then turning off suddenly atari angle to the 
edge. It runs up nearly as far on the edge of the feather as in the middle. 
Now in the European argentatus (and also in Smithsonianus,) this color is but 
little lighter than the mantle ; runs an oblique course to the edge of the 
feather ; and goes further up centrally than at the edge of the inner vane, 
where the terminal blackish descends for a little distance as a narrow margin. 
Moreover, in californicus the line of demarcation of the two colors is very 
distinct and decided, while in argentatus , they are more blended at their 
union. In discussing this point, the habitat of the californicus should not be 
lost sight of. 
With regard to the name by which this species is to be designated : — 
So far as I have been able to ascertain, the species has never been desig- 
nated by any other name than that of L. argentatusby American authors,. it 
having been always considered by them as identical with the European 
species of Briinnich. 
The Laroides americanus , Brehm, might perhaps be considered to refer to 
this species. It is, however, evidently quite a different bird. The brief 
diagnosis of Brehm is as follows : “ Unterscheidet sieli von Laroides argenta- 
toides Brehm durch den etwas kleinern Schnabel und der noch weiter hirsten 
erhohten scheitel.” Now the Laroides argentatoides of Brehm is said by that 
author, “vor alien vorhergehenden ” — L. major , argentatus and argenteus — 
“an ihrem kleinen Schnabel und ausserst hohen scheitel zu erkennen.” 
Thus, the L. americanus of Brehm is a bird with a much smaller bill even 
than L. argentatoides of that author, and therefore cannot possibly be the 
species now under consideration, which has a larger bill than argentatus , 
Briinnich. I regard it as not at all impossible that Brehm should have based 
his species ( americanus ) on a small specimen of L. californicus , but his diag- 
nosis is so brief and unsatisfactory that I do not see how the identity of the 
two names is to be proved positively. 
The Laroides argentatoides , Brehm, is given by Bonaparte and some other 
authors as the “ Lar us argentatus ex America which would make it the bird 
now under consideration. Brelim’s description, however, gives no tangible 
points of difference, and the measurements indicate a bird rather smaller in- 
stead of larger than the argentatus , Briinn. The distinctive characters from 
argentatus are summed up as lying in the smaller size, smaller bill and higher 
forehead ; — features quite a^variance with those presented by the species now 
under consideration. Moreover, the expression “sie ist nordlichate unter 
alien silbermoven,” proves decisively the non-identity of the two. I have 
been unable to find any other name which could by any possibility be referred 
to this species. 
There is, in the collection of the United States Exploring Expedition, (Vin- 
cennes and Peacock,) a G-ull labelled as having been obtained in Oregon. The 
specimen presents the characters of the present species typically, agreeing 
perfectly with eastern skins. This locality I was at first disposed to consider 
as erroneous, but very recently specimens received from J. Hepburn,- Esq., of 
1862.] 
