270 LIFE HISTORIES OF NORTH AMERICAN BIRDS. 



predominate, but in the majority of specimens these lighter tints are entirely 

 absent. Except the unspotted eggs, no two tire exactly alike. An egg kindly 

 sent by Mr. William Steinbeck for examination is heavily and uniformly 

 blotched with fawn color, hiding the ground color almost completely. At the 

 larger end this color is confluent and obscures it entirely. It is the heaviest 

 marked egg of this species I have ever seen, and is figured. In the ma- 

 jority of specimens the markings are heaviest about the larger end; in a few 

 the reverse is the case, and in others the markings, generally small in size, 

 are regularly distributed over the entire surface. There is considerable dif- 

 ference in size. The twenty specimens in the U. S. National Museum col- 

 lection mostly from Arctic regions, excepting a few collected by myself in 

 Oregon average 74.5 by 59 millimetres. The largest of these eggs from 

 Fort Yukon, Alaska, measures 81 by 64, the smallest 71.5 by 54 millimetres. 

 This was taken at Anderson River Fort, Arctic America. 



The measurements of twenty-eight specimens, all taken by Mr. Steinbeck, 

 near Hollister, California, give an average of 75 by 58 millimetres. The largest 

 of these eggs measures 76 by 63.5, the smallest 71.5 by 56 millimetres. These 

 figures are based on Mr. Steinbeck's measurements. 



Of the type specimens, No. 20699 (PI. 9, Fig. 5), selected from a set of two 

 eggs from the Bendire collection, was taken by the writer in Rattlesnake Creek 

 Canon, near Camp Harney, Oregon, April 9, 1877. It is one of the finer and 

 more uniformly marked specimens in the collection. The heavily marked 

 specimen (PL 9, Fig. 3) was taken by Mr. William Steinbeck on February 28, 

 1886, near Hollister, California, and kindly loaned for figuring. 



go. Thrasaetus harpyia (LINN^US). 



HARPY EAGLE. 



VuMur harpyia LINNAEUS, Systema Naturae, ed. 10, I, 1758, 86. 

 Thrasaetus harpyia GRAY, Proceedings Zoological Society, 1837, 108. 



(B , C , R 450, C 631, U 350.) 



GEOGRAPHICAL RANGE : Tropical America in general, south to Bolivia and Para- 

 guay, north to Mexico, and rarely to the mouth of the Rio Grande (and in 

 Louisiana ?). 



The Harpy Eagle if not the largest is certainly the most powerful of all 

 the birds of prey found on the North American continent, and can only be con- 

 sidered as a straggler, having been noticed in the Lower Rio Grande Valley in 

 Texas. No .specimens have as yet been taken within our borders. It breeds 

 in southern Mexico and thence southward as far as Bolivia and southern 

 Brazil. 



In an interesting article in the American Naturalist (Vol. xn, 1878, pp. 

 146-157), Dr. Felix L. Oswald gives the following account of the nesting 

 habits of this species. While evidently misinformed as to the size of its eggs, 

 and its occurrence in southern California, his statements otherwise are seem- 



