FALCONIDJE DIURNAL RAPTORES. 461 



but much lighter. Beneath pure white, all the feathers, including lower tail-coverts, 

 with sharp, central, longitudinal streaks of clear dark brown, the shafts of the feathers 

 black; on the sides and tibice these streaks are expanded into a more acuminate, ellip- 

 tical form; the crissum only is immaculate, although the throat is only very sparsely 

 streaked; on the ear-coverts the streaks are very fine and numerous, but uniformly 

 distributed. 



Young female, second year? (No. 26,921, Nova Scotia: W. G. Wiuton). Head above, 

 nape, rump, and upper tail-coverts, with a deep ochraceous tinge; the character of 

 markings, however, as in the male. Bands on the tail more sharply defined, the narrow 

 white bar separating the black from the grayish bands more continuous and conspicu- 

 ous; lateral feathers more mottled; grayish tip of tail passing terminally into white. 

 Beneath with a faint ochraceous wash, this most apparent on the lining of the wings 

 and tibias; streaks as in the male, but rather more numerous, the throat thickly streaked. 



Young male, first year (No. 49,662, Calais, Me.: G. A. Boardnian). Differs from No. 

 26,9:21 as follows: On the wings and upper tail-coverts the yellowish white spots are less 

 concealed, or, in fact, this forms the ground-color; secondary coverts ochraceous white, 

 with two very distinct transverse spots of dark brown, rather narrower than the white 

 spaces; tips of feathers broadly white; secondaries grayish brown, tipped with white, 

 more mottled with the same toward bases, and crossed by five bands of dark brown, the 

 first two of which are concealed by the coverts, the last q.uite a distance from the end of 

 the feathers; upper tail-coverts white, mottled on inner webs with brown, each with two 

 transverse broad bars, and a sub-terminal cordate spot of dark brown, the last not 

 touching the edge of the feather, and the anterior bars both concealed by the overlaying 

 feather. Tail grayish brown, tipped with white, and with six bands of blackish brown; 

 these bordered with white, as in the older stage. Markings beneath as in the older 

 stage, but those on the sides more cordate. Wing formula, 4, 5, 3-6-7-2-S-9, 1. 10. Wing, 

 14.00; tail, 11.50. 



Some of the examples upon which the supposed western race 

 "A. atricapillus var. striatuhis," of "History of North American Birds" 

 (Vol. III., pp. 238-240) was based, prove to be only very old birds 

 of the true A. atricapillus. They differ from the ordinary plumage 

 of the adult in the much finer pencilings of the plumage of the 

 lower parts, and more bluish cast to the upper parts. 



This daring and powerful hawk is by no means common in Illi- 

 nois, where it makes its appearance only in winter. Mr. Nelson 

 (page 119 of his list) says of it as follows: 



"Formerly a common winter resident; now very rare. Dr. A. L. 

 Marcy, of Evanston, found them quite plentiful during the winter of 

 1870-71, and obtained specimens. The only time I ever saw the 

 bird alive, was the 3d of May, 1876, at Waukegan, when a fine 

 adult specimen passed slowly overhead and disappeared toward the 

 north." 



GENUS ASTURIN"A VIEILLOT. 



Asturina VIEILL, Analyse, 1816, 24. Type Falco nitidus LATH. 



SP. CHAR. Somewhat similar to Astur, but of much heavier and more robust build; 

 tarsi longer and stouter, tail shorter and less rounded, wings longer, etc. Bill more 

 elongated than in Astur, the cere longer, and the festoon on the commissure more de- 

 veloped; nostril oval, horizontal. Wings rather short, but less concave beneath than in. 



