144 BIRDS OF THE COMMANDER ISLANDS. 



I refer it to Swiulioe's B. </riseisticU( with some doubt, however, for it 

 differs considerably from two aiitheiitic specimens of the latter from 

 China iu being much lighter and grayer above and in having the 

 dusky streaks on the under surface much smaller and paler. The white 

 on the supraloral region is broader and continues backwards in a tol- 

 erably well-detined superciliary streak. Mr. 11. B. Sharjje observes 

 (Cat. B. Brit. Mus., lY, 1879, p. 153) that "si)ecimens differ in the dis- 

 tinctness of the markings on the under surface, which is more striped 

 with brown in some examples than in others." The specimens which 

 he had before him, however, ai)pear to have been collected in the win- 

 ter quarters of these birds, and the light and *lark birds may really be- 

 long to two different races. Whether, if such being the case, Wallace's 

 B. hypogrammica would be applicable to the light race I do not knoM-. 

 but should the type of the latter name be strictly identical with Swin- 

 hoe's griseisticta, I would propose Butalis xmllens for the Bering Island 

 bird. 



From B. sibirica it is easily distinguished by having the under wing- 

 coverts and the inner edges of the quills drab-grfiy, while in B. sibirica 

 these parts are " wood-brown" (Ridgw., Nomencl. Col., pi. iii, n. 19): 

 and by having sharply-defined smoke-gray longitudinal spots on the 

 breast and the sides of the throat. The specimen in question measures; 

 Total length, ISS'"'" ; wing, SS'"'" ; tail feathers, oi"^'" ; tail beyond wing, 

 16™™. 



A single straggler among the many B. sibirica that visited Bering 

 Island in the spring of 1883 was shot on June 17. 



129 (163). Erythrosterna albicilla (Paxl.) 273. 



Occasional visitor to Bering Island during thes pring migrations. In 

 addition to the specimens secured by myself, Mr. Grebnitzki has sent 

 me a female which was captured during the spring of 1885. It (U. S. 

 ]S^at. Mus. Xo. 106608) measures as follows: Wing, 66""™; tail-feathers, 

 50"'"'. 



130 (164), Authus gustavi Swinhoe 274. 



One of the commonest summer visitors to the Commander Islands.* 

 131(166). Anthuscervinus (Pall.) 323. 



Has been obtained once on Bering Island during the spring migra- 

 tion, according to Dybowski, Bull. Soc. Zool. France, 18S3, p. 361. 



132 (168). Budytes flavus leucostriatus (Homey.) 280. 



Occasional visitor to Bering Island in spring. No authentic observa- 

 tion of its breeding there is on record. 



133 (169). Motacilla melanope Pall. 283. 



One of the rarer spring migration visitors to Bering Island, although 

 during the extraordinary spring of 1883 this species was not uncom- 

 mon there. 



" A. jajionicus from Bering Islaiid, according to Dyb. «fe Tacz., " Liste," &c.; but 

 see footnote antea. 



