244 



NORTH AMERICAN BIRDS. 



the eggs of this Hawk in Montana ; that their munbcr in a set is usually 

 two, and an unspotted white. 



Genus ASTURINA, Vieillot. 



Astiiriiia, ViEiLL. 1816. (Tyjif, FaUo niUdus, Latham.) 



Gen. Char. Somewhat similar to Astur, but ot' much heavier anci more robu.st build: 

 tarsi longer and stouter, tail .shorter and less rounded, wings longer, etc. Bill more 

 elongated than in Astur, the cere longer, and the festoon on the commissure more 

 developed ; nostril oval, horizontal. Wings rather short, but less concave beneath than in 

 Astur ; third to fourth quill longest; first shorter than eighth or ninth; four outer quills 



34002,^ . 



Asturina pla^ata. 



34008, f. 



with their inner webs sinuated. Tail considerably shorter than the wing, slightly emargi- 

 nated, the lateral pair of feathers longest. Feet large and robust, when outstretched 

 reaching almost to the end of the tail ; tarsi very robust compared to the toes, about one 

 and a half times as long as the middle toe, the frontal and posterior rows of transverse 

 scutellie very distinct and regular; outer toe longer than inner: claws strong, well curved, 

 but not very acute. Sexes alike in color ; old and young plumages very different. 



This genus is peculiar to tropical America, and contains but a single 

 species, the A. nitida, with its two climatic races, nitida of South America 

 and plaginta of Middle America. The species of BupornK, Kaup {R. mag- 

 nirosiris and E. Icucorrhoa), have been associated with the species of the 

 present genus, but they are very distinct. The genera (or, more properly, 

 subgenera) most nearly related to Asturina are Leucopterinis, Kaup, of 

 tropical America, and Kaupifalco, Bonap., of Western Africa. The former 

 differs mainly in more or less rounded, instead of emarginated, tail, and in 

 liaving the old and young plumages similar ; the latter in ha^dng the poste- 

 rior face nf the tarsus M-ithout a well-defined row of transverse scutell*. 



