1920] 



Swurth: Revision of Avian Genus Passerella 



129 



thickets. No alders now grow on that portion of Unalaska Island 

 within sight from the town of Unalaska or its vicinity, but they may 

 have done so formerly, or may now occur in other parts of the island. 

 At any rate, it seems better to retain the name unalaschensis for the 

 present form rather than to give it a new one, since the Emheriza 

 unalaschensis of Gmelin seems almost certain to have been the present 

 form. ' ' 



There is in the Museujn of Vertebrate Zoology a Passerella from 

 the island of Unalaska. This specimen (no. 4585, male adult), col- 

 lected by C. L. Hall, is labelled as from "Ounalaska, Alaska, June 4, 

 1894." There is no reason to doubt the authenticity of the skin. 

 It is one of a large collection of 

 Alaskan animals that came into 

 the possession of this Museum, 

 all taken by the same man, and 

 all carefully prepared and fully 

 labelled ; furthermore, the date 

 of capture of this skin accords 

 with other dates upon specimens, 

 from the same island, of species 

 well known to occur there. These 

 facts, together with other cor- 

 roborative evidence adduced 

 from the collection as a whole, 

 fix the origin of this fox sparrow 

 beyond any reasonable doubt, 

 even were there occasion to view 

 it with suspicion. This skin is 

 unfortunateh' a rather poorly 

 made specimen, but it is apparently of the plumbeous colored, heavy- 

 billed type above described. 



On the other hand, the considerable series of breeding birds from 

 points on the Alaska Peninsula are all of the more ashy colored, 

 slender billed type, also represented in California in winter. These 

 facts point to the further restriction of iinalaschce'nsis, as a plumbeous 

 colored, heavy-billed bird, breeding on Unalaska Island and possibly 

 some adjacent territory, with the consequent naming of a new sub- 

 species (of ashy coloration and with longer, more slenderly pointed 

 bill), breeding on at least the eastern two-thirds of the Alaska Penin- 

 sula. In the lack of an adequate series of birds from Unalaska it is 



Fig. P. Bills of specimens of Passe- 

 rella iliaca unalaschcensis, natural size. 

 These birds are from different parts of 

 the range of the subspecies, as it is now 

 defined. Note the short, stubby bill of a, 

 as compared with the long, slender one 

 of h. These structural differences are 

 correlated with differences of coloration. 



a. Adult male; no! 4585, Mus. Vert. 

 Zool. ; "Ounalaska, " Alaska; June 4, 

 1894. 



b. Adult male ; no. 90835, Amer. Mus. 

 Nat. Hist. ; Muller Bay, Alaska Penin- 

 sula, Alaska; June 1, 1903. 



