82 Oberholser, Notes on North American Birds. [iau. 



from a modern standpoint subspecies, they are now, in the male 

 at least, separated by two absolutely constant characters, on 

 account of which they should, of course, stand as distinct species. 



Circus cyaneus hudsonius (Linnaeus). 



Dr. Hartert, in a recent publication, 1 treated the American Marsh 

 Hawk, Circus hudsonius (Linnaeus), as a subspecies of the European 

 Harrier, Circus cyaneus (Linnseus). An examination of a large 

 series of both these birds has been made with the object of determin- 

 ing the desirability of this change, with the following result. 



The male of the American bird, Circus hudsonius, differs from 

 the same sex of Circus cyaneus in its less uniform, darker, and more 

 distinctly barred tail; its usually darker, less bluish (more brown- 

 ish) upper surface; darker, less clearly bluish gray color through- 

 out; and more or less barred and spotted posterior lower parts. 

 The female is also darker, but the differences in this sex are not so 

 distinctive. All the characters that separate Circus hudsonius 

 from Circus cyaneus are clearly but average, with the exception of 

 the spots on the posterior under surface, which appear to be nearly, 

 if not quite, always present to a greater or less extent in the former 

 bird. There are, however, occasional specimens of Circus hud- 

 sonius, which in this respect so closely approach the unspotted 

 condition of Circus cyaneus, and some of Circus cyaneus so much 

 like Circus hudsonius, that a trinomial designation best serves to 

 express the relationship now existing between the two birds. 

 This is apparently one of those cases of a subspecies which is in 

 about the last stages of complete specific segregation, and which in 

 the course of time will be entirely distinct. At present, however, 

 our Marsh Hawk should probably stand as Circus cyaneus hudsonius 

 (Linnaeus). 



Haliaeetus albicilla brooksi Hume. 



Dr. Louis B. Bishop, a number of years ago, recorded the Gray 

 Sea Eagle (Haliartus albicilla) from Unalaska, in the Aleutian 

 Islands, Alaska. 2 Subsequently, Mr. A. H. Clark referred the 



> Vogel palaarkt. Fauna, Heft IX (Band II, Heft 3), October, 1914, p. 1142. 

 * North American Fauna, No. 19, 1900, p. 73. 



