482 BIRDS OF THE WEST OF SCOTLAND. 



sunrise my friend being at the time a resident on the island for 

 the express object of taking notes on its ornithology and the sea 

 was unusually quiet. The bird was surrounded by kitti wakes, lesser 

 black-backed and common gulls, and presented a marked contrast 

 to the rest of the group. Mr Sinclair allowed his boat to drift 

 within twenty-five yards of its perch, and he, as well as the two 

 cragsmen who were with him, had an excellent opportunity of 

 seeing the stranger. I have since learned that pure white gulls 

 have oftener than once been noticed of late years in the same 

 place. 



Unlike its congener the kittiwake, which preys upon living 

 fishes, the Ivory Gull, in its native haunts, feeds upon whale 

 blubber and other garbage, generally associated with the fulmar 

 petrel the entertainment and the company but ill harmonising 

 with the spotless plumage of the bird. 



OBS. A specimen of a variety of this gull, which is known as the 

 SHORT-LEGGED IVORY GULL (Pagophila brachytarsus (Holboll), was 

 shot at Thrumster, near Wick, by Mr R. Shearer, and sent to Sir 

 William Jardine, who thus alludes to the bird in a paper read by 

 him before the Royal Physical Society of Edinburgh, 26th 

 January, 1859, and published in vol. ii. of the Proceedings, page 

 57: "In regard to the northern gulls, it was remarked that there 

 were two birds supposed to be confounded under the common 

 name of Larus eburneus or Ivory Gull, and it is uncertain to which 

 of these the few specimens recorded as killed in Great Britain be- 

 long. These gulls are very closely allied, and yet require careful 

 comparison. The one is Pagophila eburnea (Phipps), (Voyages 

 to North Pole, 1773); the other Pagophila brachytarsus (Holboll), 

 (in Bruch's paper, Cab. Journ. fur Ornith., 1855, p. 287). The 

 latter is distinguished by its smaller size, greater comparative 

 length of wing, short tarsi, and darker bill, tipped with bronze. 

 My principal reason for alluding to these is that a beautiful speci- 

 men of the latter form was shot a few years since in Caithness by 

 Mr Shearer, and is now in my possession (vide Proceedings Royal 

 Physical Soc., vol. i., p. 4). At the time I considered it as the old 

 P. eburnea, but I find it now belonging to the long-winged form, 

 and as such the first recorded in this country." 



I find from my note-books that I had several times noticed a 

 disparitj r of size in British-killed examples of the Ivory Gull, and 

 it is possible that this longer-winged and shorter-legged bird has 



