1920] Swarth: Revision of Avian Genus Passerella 93 



vagans, alike in their relatively bright coloration and in proportions. 

 Iliaca is by far the most widely distributed of the fox sparrow sub- 

 species. Its breeding range extends from Newfoundland to western 

 Alaska, and while certain slight average color differences have been 

 pointed out between eastern and western birds, these have not as yet 

 been demonstrated as of sufficient importance or uniformity to warrant 

 nomenclatural recognition (see Ridg-way, 1901, page 387, footnote). 

 The eastern fox sparrow (P. i. iliaca) is in life a rather plump bird 

 of "chunky" appearance. The tail is shorter than the wing, and the 

 coloration is of strongly contrasting reds and grays. It is the most 

 brightly colored of any of the races. The bill is typically Fringilline 

 in character, and of moderate size — an average sparrow bill, lacking 

 the excessive development seen in certain extremely large-billed and 

 extremely small-billed southwestern races of the species. 



In altivagans is illustrated a step from the Iliaca toward the 

 Schistacea group. As seen in its relatively heavy bill, foxy coloration, 

 and proportionate lengths of wing and tail, altivagans evidently 

 belongs within the former aggregation, but, compared with iliaca, this 

 subspecies shows a diminution in general size as well as in the bill, a 

 sobering of bright hues, and a lengthening of the tail, all clearly in 

 the direction of schistacea. 



The Unalaschcensis group contains the subspecies nnalaschcensis, 

 in-sularis, sinuosa, annectens, townsendi, and fuliginosa, distributed 

 along the northwest coast from the Alaska Peninsula to Puget Sound, 

 and apparently restricted to the immediate vicinity of the mainland 

 coast and the adjacent islands. In this group general build and 

 ratio of wing to tail are about the same as in the Iliaca group, but 

 coloration is very different. As is the case with other variable bird 

 and mammal species in the same general region, dark brown tones 

 predominate, and the grays are reduced to a minimum. Color varia- 

 tion within the group ranges consistently from one extreme to another 

 in exact accordance with the geographic position of the several races. 

 At the north is unalascKc&iisis, the least brown of any of the coast 

 subspecies, while the other races to the southward illustrate successive 

 steps in the deepening of this color, culminating in the extremely dark 

 brown "sooty" fox sparrow of the Puget Sound region. 



In connection with the coloration of the fox sparrows of the north- 

 west coast (the Unalaschcensis group) a point worthy of consideration 

 arises. All six of the subspecies involved are heavily marked and 

 noticeably brownish in coloration. This is a peculiarity that is shared 



