202 



NORTH AMERICAN BIRDS. 



thougli nowhere very distinctly apparent, appears to be of a dull white, 

 strongly tinged with a reddish hue. Distributed over the entire egg are 

 broad deep Hashes of a dark mahogany-brown, intermingled with others of a 

 similar color, but lighter in shading. These cover the egg more or less com- 

 pletely, in the greater portion of its surface. This egg. was taken near Fort 

 Arbuckle, Indian Territory, May 9, 1861, by J. H. Clark, Esq., and sent to 

 the Smithsonian Institution. 



Genus ICTINIA, Vieillot. 



Ictinia, Vieill. 1816. (Type, Falco inississippiensis, Wilson.) 

 Nertus, Boie, 1826. (Type, Falco plwnxhca, Gmelin.) 

 Poecilo2)f.crijx, Kaup, 1844. (Same type.) 



Gex. Cn.\R. Form falcon-like ; the neck short, wings long, and pointed, the primaries 

 and rectrices strong and stiff, and the organization robust. Bill short and deep, the com- 

 missure irregularly toothed, and notched ; gonys very convex, ascending terminally ; cere 

 harrow ; nostril very small, nearly circular ; feet small, but robust ; tarsus about equal to 



S2974 , ^ 



32974, f. 32974, 



/. plumbea. 



middle toe, with a distinct frontal series of broad transverse scutellye ; claws rather short, 

 but strongly curved, slightly grooved beneath, their edges sharp. Third quill longest; 

 first of variable proportion with the rest. Tail moderate, the feathers wide, broader 

 terminally, and emarginated. 



This genus is peculiar to America, the two most closely related genera 

 being Elanus on the one hand and Harpagus on the other. Its species be- 

 long to the tropical and subtropical regions, one of them (/. jplumhca) gener- 

 ally distributed throughout the intertropical portions, the other (/. mississip- 

 piensis) peculiar to Mexico and the southern United States. 



In their habits, they are very aerial, like the genus Nauchrus, sailing for 



the greater time in broad circles overliead, occasionally performing graceful 



evolutions as they gyrate about. Like Nauchrus, they are also partially 



gregarious, and, like it, feed chiefly on insects and small reptiles, which they 



eat while flying. 



Species. 



Common Characters. Adult. Uniform plumbeous, becoming lighter (whitish) 

 on the head, and darker (blackish) on the primaries and tail. Inner webs of 



