NATURAL SCIENCES OP PHILADELPHIA. 239 



ead-color, feathered in front about half way below the joint, pro- 

 tected beneath by ten large transverse scales. Toes dark lead- 

 color, large. Claws black, and strong. 



The female does not differ much from the male in the general 

 appearance of the plumage, is considerably larger, as usual with 

 the birds of prey. The back is rather lighter brown, the white 

 spots larger. 



Tail darker, more of an umber tint on the middle feathers, which 

 are edged and tipped with white. The forehead is white, but the 

 feathers of the head and neck are tipped with small lanceolate 

 spots of brown. Under parts entirely white, with fewer spots on 

 the flanks than the male, the tarsi and feet more robust, and of a 

 similar color. 



Dimensions. Male, total length 20^ inches, tail 9 inches. Female, total 

 length 22h inches, tail 9|^ inches. 



The above description is made from two specimens, male and 

 female, collected in Winnebago Count}^, Iowa, In- Mr. John Krider 

 of Philadelphia, in September, 1872, and carefully prepared by 

 that gentleman. 



He mentioned having seen several others, and described them 

 as having tlie habits and manner of flight common to the buzzard 

 family, and, from their being noticed in the autumn, were possibly 

 miorating from more northern breeding-grounds. During a pre- 

 vious visit to the same locality, in 1871, he saw a specimen 

 evidently similar to these, but was unable to secure it. Being 

 informed by residents of the country that the appearance of a 

 " wdiite hawk" there was not an unusual occurrence, heTelt con- 

 fident of ultimately procuring one, and has not been disappointed. 



Being convinced that it is undescribed, I have named it in 

 honor of the veteran naturalist to whom we are indebted for the 

 discovery. 



Spec, in Mus. Acad. Nat. Sciences, Philadelphia^ 



