Birds 99 



common Mountain Bluebird (S. currucoides) is splendid bright 

 blue in the male, without any chestnut, much grayer and duller 

 in the female. The Chestnut-backed Bluebird (S. mexicana 

 bairdi of Ridgway) is in the male ultramarine above, with a dark 

 red patch on the back, while the sides below and a band across the 

 chest are chestnut. The female is duller colored, as in other species. 

 Sclater says that this bird appears to be confined to the south of 

 the State and to the eastern foothills and neighbouring plains. 

 The Eastern Bluebird (S. sialis) is ultramarine above in the male 

 without the patch on the back, and the female has the throat 

 cinnamon like the chest. The female of S. m. bairdi has the 

 throat gray and the chest cinnamon. S. sialis is a rare bird of 

 the eastern part of Colorado, back to the foothills. Townsend s 

 Solitaire (Myadestes townsendi of Audubon) is a bird with a long 

 (about four inches) tail, the general color above slaty gray with 

 two light buffy bars. The bill is quite short and flattened. It 

 breeds in the mountains from about 7,000 feet to timber line, but 

 may be seen at lower altitudes in winter. The Western Robin 

 (Planesticus migratorius propinquus of Ridgway) is one of our 

 commonest birds, well known to everyone. Although it is migra- 

 tory, a few will often be found wintering with us. Although of 

 the same family, this bird is entirely different in size and appear- 

 ance from the English Robin, the breast of which is bright scarlet 

 or reddish orange instead of rusty red. The Eastern Robin (P. 

 migratorius') has been taken at Crook (see Condor, vol. 14, p. 151). 

 It will be known from our common Colorado bird by the darker 

 coloration, and the distinct white spot at tip of inner web of outer 

 tail feathers. The Varied Thrush (Ixoreus naevius) has been 

 reported as a straggler in Colorado. The genus Hylocichla of 

 Baird includes our thrushes, not remote from the true thrush of 

 Europe, though placed in a different genus. Our commonest one 

 is the Rocky Mountain Hermit Thrush {Hylocichla guttata audu- 

 boni of Baird), grayish brown above, cinnamon on upper tail- 

 coverts and tail; below white, with triangular dusky spots. The 

 typical H. guttata, a smaller bird (wing under five and one-half 

 inches), occurs on migration in summer and autumn along the 

 eastern foothills. There is a record of H. g. sequoiensis of Belding 

 as a rare migrant (Condor, vol. 14, p. 151). The Olive-backed 

 Thrush (//. ustulata swainsoni) is common in spring and fall. It 



