109 
NISUS TILEATUS. 
FaJco pi I eat ns Temm. PI. Col. i. 1824, pi. 205 .—Max. Beitr. iii, 1850, 107. 
Accipiter pileatus Vig Zool. Journ. i, 1824, 338 .— Gray, Geii. i, 1849, 29 ; Hand List, 
i, 1809, 33. —BoNAP.Consp. i, 1850,32.— Strickl. Orn.Syn. i, 1850,109(in part).— 
Scl. & Salv. Ex. Orn. xi, 1869, 170 ; Nom. Neotr. 1873, 120 .—Pelz. Orn. Bras i 
1871, h, 399. —Sharpe, Cat. Ace. B. M. 1874,153. 
Xmis pileatus Less. Man. i, 1828, 98.— Bukm. Tli. Bras, ii, 1855, 73.—Scnr. Mus P - 
B. Astures, 1862, 36; Rev. Ace. 1873, 70. 
Xisuspileatus var . pileatus Ridgw. Boston Soc. Pr. N. H. May, 1873 89. 
Cooperastur pileatus Bonap. Rev. et Mag. Zool. 1854, 538. 
Falco betskii Light. Nom. Av. 1854,4. 
ITab. —Brazil. 
Wing, 8.10-10.40: tail, 0.80-9.00; culmen, 0.50-0.70; tarsus, 2.20-2.05 ; 
middle toe, 1.35-1.70. Fourth and fifth quills longest, first shortest) 
outer five with inner webs emarginated. Tail slightly rounded. 
Adult :—Uniform plumbeous, except on the pileum, tibiae, crissum, 
lining of the wing, remiges and rectrices; darker above, lighter be¬ 
neath, where inclining to bluish-gray, the shafts conspicuously darker; 
pileum black ; tibiae and lining of wing uniform cinnamon-rufous"; crissum 
white, somewhat tinged with gray. Tail crossed by four to five wide bands 
of black, the interspaces grayish-brown above, white on the under surface. 
Inner webs of primaries marked with transverse spots of white or mot¬ 
tled gray and white. 
Young: —Above, dark sepia brown, the feathers bordered terminally 
with rusty, the scapulars, upper tail-coverts, and inner secondaries with 
conspicuous, large, transverse spots of white, many of them exposed. 
Pileum blackish, with rusty-ochraceous streaks in the superciliary 
region. Nape oehraceous, each feather with a central ovate stripe of 
blackisli-brown; sides ot neck similar; cheeks more finely streaked. 
Tail narrowly tipped with white, and crossed by four or five wide bands of 
brownish black, the interspaces being grayish-brown (sometimes mixed 
with white) on the upper surface, and white on the lower. Lower parts 
oehraceous or oehraceous-white, the side of the breast with lanceolate 
stripes ot blackish-brown, the sides with similar but broader stripes, 
or with broad spots; crissum immaculate. Lining of the wing ochra- 
ceous, usually more or less spotted. 
Sexes alike in color, but differing in size, as follows:— 
Male: —Wing, 8.10-8.40; tail, 0.80-7.20; culmen, 0.50-0.60: tarsus, 
2.20-2.30; middle toe, 1.35. (Five specimens.) 
Female :—Wing, 9.80-10.40; tail, 8.70-9.00 ; culmen, 0.CG-0.70; tarsus, 
2.50-2.05; middle toe, 1.65-1.70. (Seven specimens.) 
Specimens of this species vary considerably, especially those in the 
young plumage. An adult in the museum of the Boston Society of 
Natural History (No. 573, Lafresnaye collection) differs from all others we 
have seen, in having the abdomen and sides strongly tinged with rufous. 
Two young examples before us differ quite conspicuously in the mark¬ 
ings of their lower parts: No. 50,937 is deep oehraceous beneath, 
the tibiae free from markings, with the exception of two or three small 
lanceolate streaks on the longer feathers of one thigh. The other speci¬ 
men (No. 50,936) is nearly white beneath, the tibiae deeper oehraceous, 
and thickly marked with large spots of brown. In this specimen, the 
light bauds on the middle tail-feathers become white next the shaft. 
Both are females, in very young plumage. 
