84 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



coutaining a considerable number of specimens taken in Arizona by Dr. Meams 

 and now belonging to the American Museum. In addition my own collection 

 has supplied some thirteen specimens of calurits from various parts of the west- 

 ern United States. 



On examining Mr. Frazar's birds, twenty-eight in number, in connection 

 with this material I have become convinced that so far as color and markings 

 are concerned they cannot be separated from adurus, for every one of them 

 mav be closely matched by one or more of the specimens from Arizona, 

 Colorado, or California ; while even as series the birds of the two regions show 

 no obvious differences except in size, those from the United States averaging 

 slightly larger than those obtained in Lower California by Mr. Frazar. 



Buteo borealis var. lucasanus was originally described by Mr. Ridgway ^ as 

 differing from B. calurus in having " the upper parts more uniformly blackish, 

 and the upper tail-coverts and tail uniform rufous, the latter without a trace of 

 a black bar." ^ 



On examining the tail of the specimen (No. 16,925 Smith. Cat., Cape St. 

 Lucas, Sept. 15, 1859 ; J. Xantus) from which this description was taken I 

 find, however, very decided indications of a dark subterminal band. This is 

 represented by a transverse series of short, narrow, blackish bars more or less 

 broken and confused, mainly confined to the inner webs of the feathers and in 

 no instance continuous across both webs. The black is rather faint on most of 

 the feathers, but on some of the inner ones is perfectly distinct, and on one of 

 them is really sharply defined and very conspicuous, forming a solid bar, .15 

 of an inch in width, which extends from the shaft of the feather three quarters 

 of the distance across its inner web. Of the outer pair of feathers one is 

 apparently without any dark color near its tip, but both, as well as all the other 

 rectrices, have a varying number of rather large black spots on one or both 

 ■webs near the shafts, towards their bases. The tail of the type specimen (No. 

 17,212 Smith. Cat., San Xicolas, Oct. 1859; J. Xantus) lacks all trace of 

 these basal spots and at first glance appears to be perfectly plain towards the 

 tip, also, but close inspection under a strong light reveals innumerable minute, 

 dusky spots which, when the tail is spread, prove to be arranged in a regular 

 transverse series forming a faint, but unmistakable subterminal band. The 

 other three specimens labeled by Mv. Ridgway as B. lucasanus are immature 

 and do not differ from calurus in corresponding plumage. 



The majority of Mr. Frazar's birds possess tail-bands quite as well-defined 

 and conspicuous as in typical calurus, but in several of them the black is more 

 or less broken and indistinct while at least two have the band scarce better 

 marked than in the Smithsonian specimen, No. 16,925. With this .specimen 



1 Baird, Brewer, and Ridgway, Hist. N. Amer. Birds, III. 1874, 285. 



2 In the Manual N. Amer. Birds, 2d ed., 1896, 233 Mr. Ridgway apparently 

 abandons all of these characters except that of the color of the tail. In another 

 connection (Proc. U. S. Nat. Mas., V. 1883, 544) he has expressed doubts as to 

 whether the " principal character assigned to ' htcasaniis ' (the uniform rufous tail 

 without subterminal black bar) will prove constant, even in birds from the cape." 



