l--^7.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 123 



n.— LARUS AFFINIS. 



20 (24). Larus kamtschatchensis (Bp. ) 73. 



A j^oung bird of this species was shot en Bering Island on May 29, 

 1883, when I was absent in Petropaulski. It was not observed abont 

 the isUmds by me, and does not breed there. 



21 (2.5). Laxus cauus Lixx. 76. 



Apparently < 'uly an occasional visitor, like the foregoing. I shot an 

 adult female ou Bering Island November 26, 1882. 



22 (26). Larus ridibundus LiXN. 76. 



Not seen by me, but recorded as occasionally occuring on Bering Isl- 

 and on trustworthy testimony. 



When writing the part of my " Orn. Explor. Kamtsch.," I stated 

 that I had been unable to compare the eastern bird with specimens from 

 Europe. The National Museum has, since then, received a number of 

 European birds, and from Capt. Hunter, in Petropaulski, three more 

 Kamtschatkan specimens. I have carefully measured the whole series, 

 including six specimens from Japan and one from India, and can find 

 no difierence in the dimensions of eastern and western birds. The al- 

 leged larger size of the eastern birds does not exist, nor can I discover 

 any difference in regard to coloration or wing-pattern. 



23 (27). Rissa tridactyla pollicaris Stejn, 78. 



Breeds in immense flocks on both islands. Ou Bering Island it is 

 mostly confined to the southern portion. 



24 (28). Rissa brevirostris (Bruch). 82. 



Large colonies on both islands, but on Bering Island only on the 

 southeastern coast between Cape Manatee and Peregrobnij Mys. 



(30) 25. sterna camtschatica Pall. 83. 



As already remarked in " Orn. Expl. Kamtsch.," I was wrong in 

 originally asserting that this species breeds on Bering Island, the bird 

 breeding there being the common Arctic Tern. The Kamtschatkan 

 Tern is only an occasional visitor to the islands; two specimens were 

 obtained by me in the early summer of 1883. 



