THE MEXICAN BLACK HAWK. 251 



where some of them aro drawn out into irregular lines. The egg measures 

 61.5 by 47 millimetres. 



An egg sent by Lieut. H. C. Benson, Fourth Cavalry, U. S. Army, 

 from near Fort Huachuca, Arizona, identified as that of Biiteo. ahhreviatus, 

 and so described by me in the Proceedings of the U. S. National Museum 

 (Vol. X, 1887, pp. 551-552), is, according to our present knowledge of the eggs 

 of these two birds, much more likely to belong to the Mexican Black than 

 to the Zone-tailed Hawk, and although not absolutely certain of this, I figure 

 it under this species, especially as it is somewhat different from any Hawk's 

 egg in the U. S. National Museum collection. This nest was found May 6, 



1886, in a sycamore tree, in a deep arroyo near the base of the Huachuca 

 Mountains. The nest was a large and bulky one, and lined with a few leaves 

 only. It contained l)ut a single egg, which was slightly incubated. This is 

 ovate in shape, has a ground color of pale greenish white, and is sparingly 

 spotted and blotched, with small irregular markings, lines, and tracings, vary- 

 ing in color from l)urnt umber to tawny olive. It measures 51).5 by 4G.5 

 millimetres. It is No. 22930, U. S. National Museum collection, and is figured 

 on PL 8, Fig. 9. 



The Mexican Black Hawk is only a summer resident along the south- 

 western border of the United States, and nowhere common. Nidification 

 begins in the southern part of Arizona in the latter part of April, and a little 

 later northward. But a single brood is raised in a season, and one or two 

 eggs constitute a set. 



A fully identified egg of this species, taken by Dr. Mearns, on May 20, 



1887, and already referred to, now in the collection of the American Museum 

 of Natural History, is oval in shape, dull white in color, and irregularly 

 blotched, principally about the larger end, with small markings of different 

 shades of brown. This egg measures 56.5 by 46 millimetres, and is figured 

 on PI. 8, Fig. 8. 



85. Asturina plagiata Schlegel. 



MEXICAN GOSHAWK. 



Asturina plagiata (Lichtenstein) Schlegel, Mus^ de Pays Bas. Asturinse, 1862, 1. 



(B 33, C 358, R 445, C 527, U 34(1.) 



Geographical range: Middle America, south to Panama; north to sontliern 

 border of United States, in sontliern New Mexico and Arizona. 



As far as known at present, the breeding range of the Mexican Gosha^A-k 

 includes that portion of Arizona south of the Gila River and southern New 

 Mexico (Fort Bayard), and it is onl}- a summer visitor within the limits of 

 the United States, an-iving in tlie vicinity of its breeding grounds early in 

 March, and in late seasons not until the beginning of April. As it is known 

 to breed in the province of Taniaulipas, Mexico, close to our southern border, 

 it will probably yet be found nesting along the Lower liio Grande \ alle}- in 

 Texas as well. 



