FALCONID.E — THE FALCONS. 



12' 



An egg in the Smithsonian Collection (15,596), taken at Gilmer, Wyoming 

 Territory, May 13, 1870, by jVlr. H. 11. Durkee, has a ground-color of pink- 

 ish-white, varying in two eggs to diluted vinaceous, thickly spotted and 

 minutely freckled with a single shade of a purplish-rufous. In shape they 

 are nearly elliptical, the smaller end being scarcely more pointed than the 

 larger. They measure 2.27 by 1.60 to 1.65 inches. The nest was built on 

 the edge of a clift'. Its eggs were also taken by Dr. Hayden while with 

 Captain Eaynolds, at Gros Vent Pork, June 8, 1860. 



Subgenus FALCO, Mcehring. 



Fulco, McEHRiNG, 1752. (Type, Falco pcregrimis, Gm. = F. communis, Gm.) 

 Rhynchodon, Nitzsch, 1840. (In part only.) 

 Euhicrax, Webb. & Berth., 1844. (Type, Falco — ?) 

 Icthicrax, Kaup, 1844. (Type, Falco frontalis, Daud. ) 



The following synopsis of the three American species of this subgenus 

 may serve to distinguish them from each other, though only two of them 

 (F. aurantius and F. rufigularis) are very closely related. The comparative 



F. aurantius. 



61293,$, 



F. aurantius. 



51293, S . 



F. aurantius. 



52814,^, 

 F. rufigularis (nat size). 



characters of the several geographical races of the other one (F. comiimnis), 

 which is cosmopolitan in its habitat, being included under the head of that 

 species, may explain the reasons why they are separated from each other. 



