Prairie-Falecon 185 
the longest ; the outer only, or the outer two, emarginate on the inner 
web ; feet rather short, tarsus feathered or bare, without regular scutes. 
This genus contains the Falcons and Kestrels, and is found all over 
the world. 
Key oF THE SPECIES. 
A. Larger; wing over 11; only the outer primary emarginate. 
a. Clay-brown above; below with dusky, linear spots. 
F. mexicanus, p. 185. 
b. Slaty-blue above; below transversely banded with dusky. 
F. p. anatum, ad., p. 187. 
c. Blackish, edged with tawny above ; below streaked with dusky. 
F. p. anatum, juv., p. 187. 
B. Smaller, wing under 10; the two outer primaries emarginate. 
a, Tarsus scarcely as long asthe middle toe without claw ; without 
vertical black stripes on the face. 
al Tail with traces at least of four black transverse bands, 
including the broader subterminal one ; no white spots on 
the outer webs of the primaries, F. columbarius, p. 188. 
b! Tail with traces of five black transverse bands; outer web 
of primaries spotted with white. F. c. richardsoni, p. 189. 
b. Tarsus very clearly exceeding the middle toe without claw ; 
face with two vertical black stripes. 
al Smaller and more highly coloured. F. sparverius, p. 190. 
b! Larger and paler coloured, F. s. phaloena, p. 192. 
Prairie-Falcon. Falco mexicanus. 
A.0.U. Checklist no 355—Colorado Records—Henshaw 75, p. 410 
(F. lanarius polyagrus); Coues 77, p. 26; Scott 79, p. 96; Allen 
& Brewster 83, p. 197; Drew 85, p. 17; Dille 87, p. 97; Morrison 89, 
p. 65; Kellogg 90, p. 87; Lowe 94, p. 267; Cooke 97, p. 76; Hender- 
son 03, p. 235, 09, p. 229; Gilman 07, p. 154; Richards 09, p. 164. 
Description—Male—Above pale clay-brown, tinged with rusty 
and indistinctly barred with pale buffy anteriorly, and pale bluish-grey 
posteriorly ; a white nuchal collar and dark patches on the side of the 
face; primaries ashy-brown, with paler tips and whitish bars on the 
inner webs only, the outer one only with the inner web cut out ; below 
white, marked most heavily on the flanks, less so on the belly, with 
dusky, linear spots; throat unmarked; iris brown, bill bluish-horn, 
yellow at the base; cere and feet yellow. Length 17-0; wing 12; 
tail 7-25; culmen -8; tarsus 2:1. 
The female is larger—wing 13-5, tail 8-2—and has a more uniform 
appearance above without the lighter bars. Young birds have more 
