1915.] Chapman, New South American Birds. B18 
Mr. W. DeW. Miller, after an examination of our North American series, 
reports that of seventy-six males only one lacks rufous on the crown, while 
in all but three or four the rufous patch is large and conspicuous. Of eighty- 
three females the rufous crown-patch is present in all. It is reduced to a 
trace in one, and small and mixed with gray in three or four, but is large and 
conspicuous in seventy-seven. 
On the other hand, I find that in seventy-eight South American males it 
is essentially absent in sixty-five, and more or less evident in thirteen. In 
the females it is more developed, only thirty out of fifty-seven being without 
it, but in the remaining twenty-seven, only three or four approach the aver- 
age North American specimens. 
In North American specimens the outer rectrix more frequently has two 
or more bars than in South American specimens. ‘This character, however, 
is too variable to be of constant diagnostic value and I mention it chiefly ~ 
because it at times has been used in diagnosis. An examination of our 
males gives the following results: Mr. Miller reports that of seventy-six 
North American specimens, nineteen have only a subterminal bar in the 
outer rectrix, while fifty-seven have two or more bars on this feather. 
Among seventy-eight South American males I find that thirty-four have 
only the subterminal bar, while forty-four have two or more bars. This 
variability, it should be added, is shown, in a greater or less degree, by all the 
races of which adequate series have been examined. 
Geographical variation is more extensive in the South American than in 
the North American group. In the latter size and intensity of color are the 
differentiating characters. In the former there are striking differences in 
pattern as well as variations in size and color. 
Cerchneis sparverius isabellina (Swazns.). 
Falco isabellina Swatns., Anim. in Menag., 1837, p. 281 (Demerara, Br. Guiana). 
Char. subsp.— Palest of the Sparrow Hawks; the breast and upper abdomen in 
the adult male light pinkish cinnamon or white washed with pinkish cinnamon; 
the ventral region, thighs and lower tail-coverts white; the underparts usually 
without spots; white bars in the primaries wider than black ones, the terminal white 
areas usually confluent on all but the outer primary; crown with a rufous patch in 
one out of six specimens; the nape with or without black; female with the crown 
exceedingly pale, washed with rufous centrally in two of four specimens; the under- 
parts whitish more or less streaked with umber. 
Range.— Eastern Venezuela east to the Guianas.’ 
se een i ee een tee ate eee enna ke ce Sunes On eet eam 
1Two specimens from Turbaco near Carthagena, Colombia, resemble our specimens 
from eastern Venezuela. Whether they represent an undescribed form or the westward 
extension of this race through the arid coastal zone I am unable to say. 
