113 



No. 10,569, resembles tlie last in the upper parts, but with more 

 white on the throat, and the rufous nearly washed out on the breast, 

 — in the feathers of the upper part of the abdomen being barred with 

 dusky, — and in the dark spots being broader, and in the tibise and 

 crissum being barred with white, and pale fulvous. 



Buteo Harlani of the Academy, described by Mr. Cassin, in the 

 ninth volume of the P. R. R. Report, page 24, resembles very closely 

 the dark variety of calurus, with the exception of its tail, which re- 

 sembles that of an immature montanus ; as its proportions, as will be 

 seen by referring to the table, are those of calurus or montanus^ I 

 have considered it as such. 



Buteo Coo2)eri. Above, the feathers of the head and hind-neck 

 white, with a central terminal brown spot, becoming larger as it 

 descends, until, near the back, it occupies the terminal half of the 

 feather ; the back, interscapulars, and wing coverts margined with 

 rufous and whitish, and with concealed spots of whitish on the coverts. 

 The ends of the wings are hoary as if faded ; the tail rufous, mottled 

 with blackish and cinereous, forming irregular longitudinal stripes, 

 and with an obscure terminal black band. Under parts white, much 

 as in B. borealis ; the inner surface of the tibiae pale rufous, mottled 

 with brown; outer surface white, barred almost obsoletely with 

 rufous. There is nothing in the coloration of this bird that would 

 make the supposition of its being a variety of montanus improbable. 

 The tail, which shows the greatest dissimilarity, has very much the 

 appearance it would have in a semi-adult of this species, if the color 

 were partially washed out. The pro^iortions are similar ; the tarsus, 

 which appears very long, is no longer than in B. montanus, No. 4,372 ; 

 its scutellation presents, however, a peculiarity not seen in any of the 

 specimens of montanus, the outer lateral surface having on its 

 posterior edge a row of large hexagonal scales, next to which are two 

 rows of small scales, while in montanus there are three or four rows 

 of small scales, between the anterior and posterior transverse scales ; 

 there are also seven transverse scales on the middle toe, one more 

 than I have seen in montanus, which generally has only five. 



The bird described by ]\Ir. Cassin as the young of B. Harlani, also 

 presents nothing in its coloration incompatible with the idea of its 

 being a variety of montanus, but it has only a single row of large 

 hexagonal scales and one of small ones, on the lateral surface of the 

 tarsus, and the transverse scales of the middle toe extend beyond the 

 distal hall" of the first joint, being no less than eleven in number. 



After carefully examining the birds described above, I do not see, 

 if Buteo borealis, montanus, and calurus are to be considered distinct 

 species, that we can avoid increasing the number by separating from 

 montanus two species, one the dark Steilacoom variety, and the other, 

 that from Cape St. Lucas, (which, by the way, is the most distinct 



PROCEEDINGS E. S. N. H.— VOL. VIII. 8 JUNE, 1861. 



