FALCO. 24g 



a\ Two outer quills with inner webs emarginated near tip ; first quill shorter than 

 fourth. 



b 1 . Tarsus not decidedly longer than middle toe ; basal segment of toes covered 

 with small hexagonal or roundish scales. 

 Adult males : Bluish gray above, with blackish shaft-streaks ; hind- 

 neck spotted or mixed with whitish and buffy or ochraceous ; quills 

 dusky ; tail crossed by a greater or less number of blackish bands, 

 and tipped with whitish; lower parts whitish, buffy, or light rusty, 

 striped with brownish or dusky. Adult females : Brownish above, 

 the tail usually with a greater or less number of lighter (usually 

 narrow) bands ; top of head streaked with blackish, and feathers of 

 back and rump with shaft-streaks of the same ; lower parts much as 

 in the male, but without rusty tinge. Young (both sexes) : Much like 

 adult female, but darker, or else much tinged above with ochraceous 

 or rusty. (Subgenus JEsalon Kaup.) 

 c 1 . Middle tail-feathers of adult male crossed by about six imperfect, mostly 

 concealed, blackish bands, besides the broad and continuous subter- 

 minal one; that of adult female and j'oung crossed by about eight 

 light bands, including terminal band. Adult male with closed tail 

 showing one black band, this a broad subterminal one ; inner web 

 of longest quill with about ten white spots ; hind-neck, breast, and 

 sides more deeply rusty than thighs; dark markings on breast 

 linear, and streaks on cheeks crowded into a distinct "mustache"; 

 length about 11.00, wing 7.60-8.00, tail 5.10-5.30, culmen .45-50, 

 tarsus 1.35-1.45, middle toe 1.15. Adult female: Tail with about 

 eight narrow pale bands (more on lateral feathers), the first two 

 or three concealed, however, by upper coverts ; upper parts usually 

 much spotted with a lighter tint than ground-color; length about 

 12.00-14.00, wing 8.60-9.00, tail 6.00-6.30, culmen .52-.55, tarsus 

 1.45-1.47, middle toe 1.20-1.25. Young : Similar to adult female, 

 but more or less tinged with rusty, the lighter spots on upper parts 

 more distinct. Sab. Europe, etc. ; accidental at sea near coast of 

 Greenland. 



F. regulus Pall. Merlin. 1 

 c s . Middle tail-feathers of adult male crossed by not more than four black- 

 ish bands besides the broad subterminal one, that of female and 

 young never with more than six light bands, including terminal one. 

 Adult males with closed tail showing more than one black band ; 

 inner web of longest quill with less than ten white spots ; hind-neck, 

 breast, and sides less tinged with rusty than thighs ; markings on 

 breast broad, stripe-like, and streaks on cheeks not crowded into a 

 distinct "mustache." 

 d 1 . Middle tail-feathers with not more (altogether) than four blackish 

 or five lighter bands. 



1 Falco regulus Pall., Reis. Russ. Reichs. ii., Anhang, 1773, 707. 

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