NATURAL SCIENCES OF PHILADELPHIA. 
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vane wholly of a lighter shade of the same color to within three inches ; this 
gray ends very abruptly, being almost truncated, as it were ; third, like the 
second, but the gray extends further (nearly as far on the outer as on the 
inner web), to within about two inches of the tip, which has a minute gray 
apical spot ; fourth, wholly leaden gray to within one and a half inches of 
the tip, which has a larger apical spot than the second ; fifth, the leaden gray 
body of the feathers is separated from the well-defined and now white apex 
by a band of black, less than an inch long ; and the gray begins to be edged 
internally with white ; sixth, gray, fading into white at the tip and internal 
border, with a small subapical spot of black on one or both webs ; other pri- 
maries like the sixth, without any black. This “ gray” of the primaries is 
precisely the color of the mantle. Legs and feet in the dried specimen light 
straw yellow ; probably tinged with coral red in life. Claws black. Dimen- 
sions : Bill along culmen 1*19 inches; depth at base *50; width *42; depth 
at angle same ; nostril to tip -60. Wing 13-00 ; tarsus 1-25 ; middle toe and 
claw 1-95. (No. 24,296, S. I. Coll, from Kamtschatka.) 
Habitat. — Kamtschatka. 
This is a very strongly-marked species, and one which it is impossible to 
confound with any other. The fine specimens before me agree in the minutest 
particulars with Gould’s description. Its peculiar characters of the shape of 
the bill, its color and that of the feet, with the dark mantle and the peculiar 
style of the markings of the primaries, separate it widely from any other Gull 
with which I am acquainted. Having never seen the young bird, I am totally 
unacquainted with the changes of plumage which the species undergoes. 
Having thus characterized the two species of Rissa from the Northwest 
coast, I proceed to the difficult task of discussing their intricate synonyms. 
While it is believed that the characters of the species are accurately given, 
the hope is scarcely indulged that the synonyms are more correctly assigned 
than they have hitherto been by previous authors. 
Concerning the proper location of no name bas there been a greater dif- 
ference of opinion among authors than of Larus niveusoi Pallas ? Many writers 
consider it a Rissa, and refer it to the R. brachyrhyncha of Gould. Bonaparte 
considers it a true Larus, and makes it a distinct species. I am decidedly of 
opinion that it is a true Larus, and very closely allied to, if, indeed, not identical 
with, the Larus brachyrhynchus , Richardson, of this paper. Let us examine the 
characters given by Pallas. “ Rostrum virescente-flavum.” There is no trace 
of greenish in the bill of Rissa brachyrhyncha, which is a clear straw yellow. 
“ Pedes fusci.” The feet of Rissa brachyrhyncha are yellow, with a tinge of 
coral red. With his known accuracy of description, Pallas could hardly have 
made such a mistake as this ; and hence, I do not see why Bruch has identi- 
fied the bird with Rissa brachyrhyncha. In Pallas’ description thus far, there 
is nothing absolutely inconsistent with the characters of C. Kotzebui of this pa- 
per. The description continues, however, ‘ ‘ apice alserum nigro prsecedenti simil- 
limus.” The preceding species is L. cachinnans , Pall., the description of the 
primaries of which is, “ remiges 1 ad 6 extremitate nigrae, extimse sensim ulte- 
rius ; duae extimae macula transversa albaet apice, 3 ad 6 tantum apice albas.” 
This is the usual pattern of coloration of the primaries of Herring- Gulls, and 
very different from that which obtains throughout the genus Rissa, being 
equally inapplicable to either species of the genus. It is true that the plate 
gives no indication of these subapical spots on the primaries ; but in the case 
of conflict, the text should certainly have precedence. Is the bird, then, a 
Rissa ? If we examine Pallas’ descriptions of his Larus rissa, L. torquatus , or 
L. gavia, we find that he is very careful to use the expressions “ tridactylus” 
and “ subtridactylus,” and it seems hardly probable that the rudimental cha- 
racter of the hind toe would have passed unnoticed. The plate shows the 
hind toe and claw as fully formed as many species of Larus, and there is no 
expression in the text contradicting it. While I am thus of opinion that the 
1862.] 
