G40 LARUS CANUS VAR. BRACHYRHYNCHUS, MEW GULL. 



at nostrils, 0.25; height, 0.35; height at angle, 0.35; tarsus, and miadle toe and 

 claw, 1.80. 



The variations in size presented by this species, thouah considerable, are not greater 

 than those of others of the genus. The difference in the lengths of the wiug, tarsns, 

 and bill, of the largest and smallest specimens before me, amounts to, respectively, 1.80, 

 0.30, and 0.20 inches. There is a considerable difference also in general size, which, 

 however, is not always accompanied with corresponding discrepancies in length of bill 

 and feet, small birds having sometimes longer bills and tarsi than those whicli surpass 

 them in total length ; the indefinite character of these variations showing pretty con- 

 clnsively that they are those of a single species. As might be expected, adult birds, 

 as a general rule, are larger, with longer and stouter bills than the young. As will be 

 seen in the diagnosis, during the breeding season the bill, mouth, eyelids, and feet, be- 

 come very highly colored, although the bright tints are retained for only a short time. 

 There may also be .sometimes detected a faint rosy blush on the under parts during 

 this season. In adult birds the markings of the primaries are very constantly pre- 

 served. The relative proportions of the tarsus 'and toes vary a little, but tho former 

 never greatly exceeds the latter in length, as is always the case with canus and 

 zonorhynchus. 



I have before me the type-specimen of Richardson's Larus hranhyrliynchus — the 

 original of his description in the Faun. Bor. Am. — " a female, killed on the 23d of May, 

 1826, at Great Bear Lake." "Some brown markings on the tertials, primary coverts, 

 and bastard wiug, with an imperfect subterminal bar on the tail, point it out as a 

 young bird, most probably commencing its second spring." The specimen in qnestioQ 

 is labeled in a handwriting unknown to me, " 2 , May 23, 1826, Great B ar Lake," and 

 corresponds in every detail with Richardson's description, so there can be no doubt of 

 its identity. This author, in drawing up his diagnosis of the species from a young 

 bird, fell into the error of saying "remigibus apicfe concoloribas," whereas in the adult 

 the primaries are as broadly white tipped as in other species. In this type-specimen 

 the bill is very small, bearing perhaps less than the average even of young birds, but 

 in other specimens before me it is quite as short. 



This is the North American representative of the European canus, but is varietally 

 distinct in the following features : The tarsus little if any longer than the middle toe 

 and claw, instead of beujg a fourth longer. The bill is shorter and smaller in all its 

 proportions, with a rather more convex culmen and less developed eminentia. The 

 bluish bases of the primaries are much lighter, fading nearly into white at their junc- 

 tion with the black portion ; extend for a greater distance along the feathers, and rnn 

 up further in the centre than along the edge of the inner vane. The average size of 

 the bird is less, and the color of the mantle rather lighter. 



The differences between this species and delawarensis, the only other American species 

 which it at all resembles, are so palpable that a detailed comparison is scarcely necessary. 



Synonymy. — Much confusion prevails in the synonymy of this species, for which there 

 is really no occasion, as it is perhaps the most thoronghly marked of all our North 

 American species. Most authors present it as a synonym of zonorhynchus (delawarensis) ; 

 and in addition several nominal species must be referred to it. The difficulty doubtless 

 originated in the reference by some of Larus canus "Linn." of Richardson to the true 

 European canus, and by others to the zonorhynchus Richardson. Brachyrhjnchus Rich- 

 ardson being founded upon an immature bird naturally excited suspicion as to its 

 validity, heightened by the fact that Richardson himself expresses doubts of its dis- 

 tinction from his canus. 



The proper location of Larus niveus Pallas is a point upon -wliich authors widely 

 differ. Bonaparte considers it as a valid species. Cassin queries it as a synonym of 

 occidentalis Audubon. Bruch, and following him Lawrence, consider it as a Rissa, iden- 

 tifying it with iracliyrhyncha* Gould (uot of Richardson). I see nothing in Pallas' 

 description or piate which renders its reference to the large Asiatic form of canus inad- 

 missible. The jilate, it is true, shows no subterminal spots on the primaries, but this 

 is contradicted by the text, which says that the bird is in this respect "entirely like 

 the preceding," -which is L. cachinnans Pallas, a species the description of whose pri- 

 maries shows it to be not essentially diverse from brachyrhynchus Richardson. The 

 measurements given are those of an adult irachyrhynchns. The doubt involved appears 

 to be this. Pallas' bird is from Kamtschatka, and is doubtless the species described by 

 Middendorfif as L. canus major (Siberische Eeise, Birds, p. 213). The question then 

 really hinges upon the identity or distinction of the Asiatic and American bird. The 

 former, according to Middendorffj is larger than canus, and has a bigger bill, while the 

 American bird is as much smaller and weater billed. But it appears that there is in 

 Siberia, &c., a distinct variety, larger than the standard European canus, just as there 

 is in North America one smaller than the latter. In view of these considerations there 

 seems to be no doubt that niveus Pallas is the larger form, which I recognize as L. canus 

 var. nireiis. 



* For discussion of this view see lielow, under head of Bissa hrachyrhyncha. 



