260 AVES: RAPTORES. — XLI. 
426. FALCO Linneus. Fatucons. (Lat., falcon.) 
a. First primary only emarginate on inner web; tarsal plates small; sexes 
colored alike. 
6. Tarsus longer than middle toe and claw. 
c. Tarsus feathered in front more than half way down. (Hierofalco 
Cuvier.) 
820. F. rusticolus (L.). Gray Gyrratcon. Bluish gray 
above with dark bands; lower tail coverts always with ashy; young 
plain above, streaky below. L. 24. W. 16. T. 10. Northern 
regions; var. obsoletus, S.to U.S.in winter. This form is darker, 
the lower parts chiefly dusky. (Hu.) (Lat. rural.) 
cc. Tarsus not feathered more than half way down in front. (Gennaia 
Kaup.) 
821. F. mexicanus Schlegel. Prarrre Faucon. Grayish 
brown, more or less barred and streaked. L.18. W.14. T.8. 
S. W., E. to IIL, allied to the Lanier of Europe. 
bb. Tarsus not longer than middle toe, scarcely feathered below heel joint. 
(Rhynchodon Nitsch.) 
822. F. peregrinus Tunstall. PEREGRINE Fatcon. Duck 
Hawk. Blackish ash with paler waves; top of head black ; below 
whitish ; black cheek patches. L. 16. W. 13. T.7. Northern 
regions, not very common; the American bird, var. anatum Bona- 
parte, has the breast unstreaked. (u.) 
aa. Two primaries emarginate; tarsal plates enlarged in front, appearing 
like scutella. 
d, Tarsus about equal to middle toe; basal joints of toes with small hex- 
agonal scales. (salon Kaup.) 
823. F. columbarius L. Pigeon Hawk. AMERICAN MER- 
LIN. Ashy blue or brownish above with darker streaks; lower 
parts whitish or buffy, streaked with brown; middle tail feathers 
in g with about 4 black bands; in 9 with about 6 pale bands. 
L.13. W.8. T.5. U.S. (Lat., pertaining to a pigeon.) 
dd. Tarsus longer than middle toe; basal joints of toes with transverse 
scutella. (Tinnunculus Vieillot.) 
824. FP. sparverius L. Sparrow Hawk. Rusty Crownep 
Fatcon. Back tawny; wings bluish and black in ¢ ; seven black 
blotches about head ; tail chestnut, with a broad black band in 
¢, and a narrow terminal one of white ; below white or tawny. 
? different, more streaky, the tail tawny with numerous narrow 
darker bars; back and wing coverts rusty barred with black. One 
of the most active and courageous of the hawks; a genuine falcon, 
notwithstanding its small size L. 11. W. 7 T.5. U.S, 
abundant. (Lat., relating to a sparrow.) 
