iSq4 1 R IDGWAY > Geographical Variation in Sialia vicxlcaua. 1^7 



by an indistinct orbital ring of dull grayish white; malar region, chin, 

 and throat, pale grayish brown; whole breast dull light cinnamon, this 

 color extending (more faintly) over sides but disappearing on flanks; 

 rest of under parts similar in color to throat, passing into dull whitish on 

 lower belly and anal region; lower tail-coverts grayish blue centrally, with 

 blackish shaft-streaks, and bioadly margined with grayish white. ' Bill 

 and feet brownish black. Total length (skin), 6.10; wing, 3.95 ; tail, 2.45; 

 exposed culmen, 0.45; tarsus, 0.82; middle toe, 0.60. 



Adult female in autumn (No. 2,949, Columbia River; J. K. Townsend) : 

 Similar to the spring plumage, as described above, but colors more suf- 

 fused, the blue less bright, top of head and hind-neck more strongly 

 tinged with blue, whitish orbital ring much more distinct, the breast and 

 sides deeper cinnamon-brown. Total length (skin), 6.50; wing, 3.97; 

 tail, 2.42; exposed culmen, 0.45; tarsus, 0.85; middle toe, 0.63. 



b. Chestnut-backed form (S\ m. bairdi). 



Adult male in spring- 1 (type of 5. m. bairdi Ridgw., No. 7637, Camp 

 no, "New Mexico," Jan. 31, 1854; Kennedy and Mollhausen) : Head and 

 neck all round, chest, and upper parts except back and scapulars, rich 

 ultramarine-blue, with a tinge of smalt-blue, rather paler on chin, throat, 

 and chest; entire back, including most of the scapulars, uniform chestnut, 

 forming a 'solid' shield-shaped patch, abruptly defined anteriorly against 

 the blue of the hind-neck: upper tail-coverts with indistinct blackish 

 median streaks; ends of remiges abruptly blackish dusky, with very 

 narrow but distinct terminal margins; shafts of remiges and rectrices 

 glossy black. Entire breast (except lower median portion), sides, and 

 flanks, uniform chestnut, of a rather lighter more rusty shade than that on 

 the back ; lower median portion of breast and upper part of abdomen, 

 bright grayish blue, like throat and chest; rest of belly light bluish gray 

 becoming whitish about the anal region ; under tail-coverts light cam- 

 panula-blue, margined with white. Bill and feet black. Total length 

 (skin), 6.60 (6.25 before skinning); wing, 435; tail, 2.75; exposed 

 culmen, 0.45; tarsus, 0.80; middle toe, 0.52. 



Adult male in autumn (No. 68,442, Black River, Arizona, Oct. 7, 1S74; 

 H. W. Henshaw) : Similar to the spring plumage, as described above, 

 but blue of head, neck and chest obscured by brownish gray tips to the 

 feathers (these more rusty on the chest), chestnut of back and scapulars 

 duller and broken by paler tips to the feathers, that of the chest also 

 varied with paler tips; blue of upper belly and median lower breast rather 

 paler and duller. Total length (skin), 6.20; wing, 4.43; tail, 2.85; 

 exposed culmen, 0.40; tarsus, 0.80; middle toe, 0.5S. 



1 Although the date is so early the plumage is in perfect condition, without a trace 

 of the paler, duller tips to many of the feathers which characterize the autumnal and 

 early winter dress. 



