EALCONID2E DIURNAL RAPTORES. 437 



coverts with more or less conspicuous cordate spots of black, rather sparsely distributed ; 

 basal two thirds of secondaries, and whole of primaries, deep black, the latter whitish 

 around the terminal margin, and with nine transverse bands of white on inner web of 

 longest (second), the white rather exceeding the black, the points of which do not reach 

 the edge of the feather; lining of the wing white, with conspicuous cordate spots of 

 black. Front and superciliary region more hoary than the forehead, almost approach- 

 ing white. Whole lateral region of the head, with chin, throat, and lower parts, white; 

 the neck, breast, and sides, however, with a deep tinge of ochraceous, the tint hardly 

 approaching the depth of color seen on the nape. On the head there are (considering 

 both sides) seven black spots, the first originating in front of the bare anteorbital space 

 (leaving the lores white), and extending in a stripe downward across the malar region, 

 forming a conspicuous "mustache;" the second crosses the tips of the ear-coverts, in 

 the form of an oblong transverse spot; the third is smaller, situated as far behind the 

 last as this is posterior to the "mustache," crossing the side of the neck. The last is an 

 odd nuchal spot, separating the ash of the occiput from the rufous of the hind-neck. 

 Breast and sides with circular or cordate spots of pure black, these varying in size, but 

 generally larger on the sides. Other lower parts immaculate. Wing formula, 2=3-4, 1. 

 Wing, 7.10; tail, 4.50; tarsus, 1.32; middle toe, .98; culmen, .45. 



Adult female (No. 10,751, Fort Bridger, Utah: C. Drexler). Blue above confined to the 

 head, which shows rufous patch as in the male ; entire upper parts rufous, lighter and 

 less purplish than in the male, everywhere barred with black. Tail with twelve sharply 

 defined narrow bars of black, the subterminal broadest, and about Ithree eights of an 

 inch in width. Longest primary with eleven transverse spaces of pale rufous, nearly 

 twice as wide as the dusky ones, which scarcely touch the edge. Beneath yellowish 

 white, paler than in the male; breast and sides with rusty longitudinal spots. Head as 

 in the male. Wing, 7.60; tail, 5.20; tarsus. 1.50; middle toe, .90; bill,.50. Wing formula, 

 2=3-4~L 



Young male (No. 5,581, Medicine Bow Creek, Nebraska, August 7, 1856: W. S. Wood.) 

 Exactly like the adult male, but with rufous darker, approaching to chestnut; spots be- 

 neath inclining to a tear- shaped form, and, though more numerous, not so well defined 

 as in the adult; also rufescent tinge beneath more general; blue of the wings with 

 scarcely any spots; white terminal band of tail tinged with rufous. Sometimes the two 

 or three outer feathers are clouded with ash, and possess indication of bars, formed of 

 irregular black spots. 



Young female (No. 40,520, Fort Eice, Dakota: S. M. Rothhammer). Generally like the 

 adult, but with rufous above darker, approaching ferruginous; the bars everywhere 

 broader, and purer black ; rufous vertical patch streaked centrally with black; spots be- 

 neath larger, darker, approaching reddish umber. 



VARIATIONS. While perhaps a majority of specimens of this species 

 agree very nearly with those described above, there is nevertheless 

 a very wide range of individual variation, in each plumage. Speci- 

 mens from the eastern United States are apparently more variable 

 in their markings than western examples, and this is true of any 

 locality within that region. The extreme variation reached in this 

 portion of the continent is that plumage upon which Swainson 

 based his Falco isabellinus, which is characterized (1) by the uniform 

 dark plumbeous pileum, the usual rufous crown-spot being absent 

 or much reduced in size; (2) by the whole breast and jugulum, in 

 the adult male, being immaculate deep ochraceous or buff, the few 

 spots, should any be present, confined to the sides. The females 

 of this style are much darker colored than those in the normal 



