LARUS BEEVIEOSTEIS, KED-LEGGED KITTIWAKE. G47 



(^)Iii8sa h-achi/rhyncha, Brdch, J. f. O. 1853, 103. 



Missa brachtjrhi/iidia, Bp., Consp. Av. ii, 1856, 226.— CoUES, Pr. A. N. S. Phila. 1862, 306. 



Eissabreriroslris, "Bkandt."— Bruch, J. f. 0. 1855, 285.— Lawp,., B. N. A. 1858, 855 



{parnm).—DA.Lh & Bann., Tr. Chic. Aciul. i, 1«69, 30.5. 

 Larus hrerii-oslrls, Codes, Key, 1872, 315 ; Elliot's Prybilov Islands (biography, &c.). 

 (?)ia»-H.s loarncclcii, Comde, K. M. Z. 1860, 401. 



DiAG. L. albus, paUio cinereo, pagonio exieriore ct apice remigis 1"' nigris, rcmigiius 2^", 

 Sti", et 4'° notd apicali cinercu, 5*° vittd nigra et apice cinereo ; rostro Irevi, flamssimo, pedi- 

 bus rubroflavis. 



Hob. — North Pacific, both Asiatic and American. 



Sp. ch. AdtiU. breeding plumage. — (No. 24296, Smithsonian Museum ; from Kamt- 

 schatka; received from Mr. Gould.) Bill very short, stout, wide at the base, the upper 

 mandible much curved, though not attenuated nor very acute. Convexity of culmen 

 very great toivard the tip ; the culmen beiug, from the nostrils to the apex, almost the 

 arc of a circle, whose centre is the syraphyseal eminence. Outline of rami of under 

 raaudible and gonys both somewhat concave ; the eminentia symphysis but slightly 

 developed. Tarsus very short, hardly more than two-thirds the middle toe and claw. 

 Wings exceedingly long, reaching, when folded, far beyond the tail. Tail of moderate 

 length; even. 



BUI a uniform clear light straw-yellow, with no tinge of olivaceous (some speci- 

 mens, however, are thus tinged). Head and neck all round, under parts and tail, pure 

 white. Mantle deep leaden or bluish-gray, much darker thau in B. tridactyla ; the 

 color on the wings extending to withiu half an inch of the apices of the secondaries, 

 which terminal half inch is white. Primaries: the fimt has its shaft and outer vane 

 black, but has on its inner vane a space of dull gray (not tvhite), which at the base of 

 the feather occupies nearly all the vane, but gradually grows narrower until it ends by 

 a well-defined rounded termiuatiou half as broad as the vane itself, about 2-J inches 

 from the tip of the feather, these 2^ inches being black, like the outer vane. Second : 

 The outer vane is of the same leaden gray as the back, to within 4 inches of the tip ; 

 the inner vane is of a rather lighter shade of the same color, to within 3 inches of the 

 tip, the gray ending abruptly, being in fact almost truucated. Third : Like the secoud, 

 hut the gray extends further, leaving only a space of 2 inches black ; and the tip has 

 also a minute apical gray spot. Fourth : Wholly bluish -gray to within li inches of the 

 tip, which has a larger gray apical spot thau has the third, so that the black is less 

 than li inches long. Fifth : The gray extends so far that it is separated from the well- 

 defined white apical spot by a band of black less than 1^ inch wide. Sixth : Gray, 

 fading into white at the tip, and with the black reduced to a small subapical spot on 

 one or both wehs ; other primaries like the sixth, minus the black spot. (This " gray " 

 of the primaries is the color of the mantle.) Legs and feet in the dried specimen clear 

 straw-yellow (in life coral-red, especially the toes and webs ; the tarsi themselves not 

 quite so bright). Claws black. 



Dimensions. — Bill, along culmen, 1.20 inches ; along rictus, about 1.70 ; from nostril t:> 

 tip, 0.60; depth at base, 0.50 ; width, 0.42 ; depth at symphyseal eminence, 0.42 ; wing, 

 13 ; tail, about 5 ; tarsus, 1.25 ; middle toe and claw, nearly 2 ; length of the whole 

 bird, apparently about 14 inches. 



In the above specimen the feet are plain yellow ; in one more recently obtained (No. 

 54695, St. George's Island, August 15, 1868 — W. S. Dall) the toes and webs are coral, 

 almost vermilion red ; the tarsi nearly yellow, but apparently already faded some- 

 what. This bird agrees minutely with Gould's typical specimen ; the bill, however, is 

 a little more attenuated toward the tip, with less convexity of the culmen, and is 

 clouded with olivaceous. It appears to be perfectly mature. I have since examined 

 scores of specimens from the Prybilov Islands — they are all alike red-legged. 



I know of no species that resembles this one so intimately that detailed comparison 

 is required for the separation of the present. The species is in fact one of the more 

 strongly marked of the subfamily : The shape and color of the bill ; the relative pro- 

 portions and color of the feet ; the dark mantle and peculiar pictura of the primaries, 

 stamp it with an individuality not easily overlooked or misunderstood. 



Young birds I have not seen ; but I presume that the changes of plumage will he 

 found correspondent with those of B. tridactyla. The bill may be hlack, very likely ; 

 there may be a bar of black on the wings, and another across the back of the neck ; 

 but this, it must be cautioned, is merely supposititious on my part. Of the color of the 

 feet of the young I prefer not to conjecture. 



So much has been said of the hind toe of Pacific Bissw that it is incumbent upon me 

 to add my testimony in resi^ect of this species in this particular. The hallux of B. 

 brevirostris is not appreciably larger than that of tridactyla ; it bears a minute, abortive 

 black claw — a mere speck of corneous, as distinguished from cuticular, tissue. I should, 

 not on this account, say that the hind toe was better developed than in B. tridactyla ; 

 hut some authors may have done so, thus further entangling the Bissa question ; for it 



