212 



LONG-WINGED SWIMMERS — LONGIPENNES. 



in winter: Similar to the summer plumage, but head and neck streaked with jiale brownish gray. 



"The bill is wine-yellow, the lower mandible Avith an orpiment patch near the end ; the edges 



of the eyelids pale yelltnv ; the feet flesh-colored, the claws bluish black" (Macgillivray). 



Young, first plumage : Ashy white, more or less tinged with pale brownish ash below, the upper 



jiarts more or less mot- 

 tled transversely with 

 the same ; head and 

 neck faintlj' streaked 

 with the same. Ter- 

 minal third of bill 

 dusky, basal portion 

 flesh-color ; legs and 

 feet flesh-color ; " iris 

 yellowish brown " 



(KUMLIEN, MS.).i 



Young, in second win- 

 ter : Wholly juire 

 white, the bill and feet 

 colored as above. 

 Downy young (No. 

 76217, Kingwah Fiord, 

 Cumberland Gulf, 



June 24,1878; L.KuM- 

 lien) : Grayish white, 

 paler below ; head 

 and neck irregularly 

 marked with scattered 

 large spots of dusky ; 

 back, wings, and rump 

 Bill brownish, crossed by a broad dusky band ; feet 



Adult. 



irregularly clouded with dark grayish 

 light brown. 



Total length, 28,50 to 32.00 inches ; extent, 57.00 to 65.00 ; wing, 16.75-18.60 (17.93) ; culmen, 

 2.15-2.65 (2.44) ; depth of bill through angle, .75-1.00 (.85) ; tarsus, 2.30-3.00 (2.70) ; middle 

 toe, 1.95-2.50 (2.26). [Fourteen .specimens.] 



There is a very great amount of individiuil variation in this species, some specimens being hardly 

 distinguishable from L. leucojHerus, while others are larger than the average of L. marinus. We 

 have found it exceedingly difficult, witli a series of eighteen examples of both species before us, to 

 define the limit between glaucus and leucopterus, the coloration being quite the same in the adult 

 stage, and the individual variation in each so great that they very nearly intergrade, notwith- 

 standing the vast difference in size between the largest specimens of the former and the smallest of 

 the latter. The variation in size seems to be individual and sexual rather than local. 



The Burgomaster Gull appears to be confined, during the summer, to the northern 

 shores of the Atlantic and Pacific oceans, and to the connecting portions of the Arc- 

 tic; Sea. It is peculiarly a high northern species, being found in the Arctic Ilegions 

 of Europe and Asia, and in the more northern portions of North America. In the 

 Pacific it appears to be to a large extent replaced, on the American shore, by the 

 glaiteescens. 



Messrs. Evans and Sturge, in their visit to Spitzbergen, found it breeding in ini- 



1 Macgillivray ("Hi.st. Brit. P>." V. 563, 564) describes thu fresh colors of the bill, etc., in the young as 

 follow.s : " Young : The bill is horn-color, or pale yellowish gray ; the upper mandible brownish black be- 

 yond the nostrils ; the lower beyond the angle. The feet are flesh-color ; the claws lightish brown. Youmj, 

 in third winter : The bill is ycllowisli flesh-color, with only a dusky spot on each mandible toward the 

 end ; iris dull gray ; the edges of the eyelids yellow ; the feet flesh-color ; the claws light grayish f)laek." 



