418 NORTHERN ZOOLOGY. 











Dimensions. 















Inch. 



Lin. 







Inch. 



Lin. 





Inch. 



Lin. 



Length, total 



23 







Length 



from nostrils to tip 







ii 



Length of inner toe 



1 



6 



„ of tail 



7 



3 



ii 



of nostrils . 







41 



,, of inner nail . 



. 



4 



,, of wing 



10 



6 



ii 



of tarsus 



. 2 



4* 



„ of hind toe 







3 



,, of bill above 



2 







n 



of middle toe 



2 



1 



„ of hind nail . 



. 



n 



,, of bill to rictus 



. 3 







ii 



of middle nail 



. 



5 









Six individuals, killed on Melville Peninsula, in June, July, and September, varied in total 

 length from 23 to 25 inches, and in the length of their tarsi from 27 to 31 lines. — R. 



[183.] 3. Larus leucopterus. (Faber.) White-winged Silvery Gull. 



Genus, Larus, Linn. 



Larus argentatus. Sab. Birds of Greenl., p. 546. 



Larus arcticus. Macgillivray, Wern. Trans., v., p. 268. 



" Larus glaucoides. Temm." 



Larus leucopterus. Bonap. Syn., No. 301. 



During Captain Ross's and Sir Edward Parry's first voyages, many specimens 

 of this Gull were obtained in Davis's Straits, Baffin's Bay, and at Melville 

 Island. Temminck, to whom they were communicated, considered it at first to 

 be merely an Arctic variety of L. argentatus ; and, in deference to his authority, 

 it was described as such by Captain Sabine. Both he and other ornithologists 

 have, however, since that time, published it as a distinct species under different 

 appellations, the one which we have selected having the priority. The plumage 

 of L. leucopterus differs little from that of L. glaucus ; but the great superiority 

 of the latter bird in point of size is sufficient to distinguish the species. — R. 



DESCRIPTION. 



Colour. — Mantle pearl-grey ; quills fading to white, their shafts pure white, as well as 

 the rest of the plumage. Bill wine-yellow, with an orange-coloured spot near the tip of the 

 lower mandible. Feet flesh-coloured. 



Form. — Bill compressed, deep ; upper mandible considerably longer than the under one. 

 Nostrils narrowly pyriform. Wings equal to the even tail*. 



Dimensions. 



Inch. Lin. Inch. Lin. Inch. Lin. 



Length, total . 26 Length of tarsus . .26 Length of middle nail . 5 



,, of bill above .26 ,, of middle toe .2 1 Extent of wing . . 50 



* This description is compiled from Mr. Macgillivray's account, above quoted, — no specimens having been obtained 

 on Sir John Franklin's Expeditions, and Sir E. Parry's not being at hand. — R. 



