250 



Mearns, Descriptions of New Birds from Arizona. 



I July 



the Pacific coast of the United States, M. formicivorus from 

 southeastern Mexico and Central America, and M. formicivorus 

 angustifrons from Lower California, in the American Museum of 

 Natural History, New York, the U. S. National Museum at 

 Washington, and the cabinet of Mr. George B. Sennett, shows 

 that it is subspecifically separable from either of the above forms. 

 It differs from all of them in the small size and peculiar shape of 

 the bill, but is in most respects intermediate between M. formi- 

 civorus bairdi and Af. formicivorus. 



Adult (Type, No. 6345, Coll. E. A. Mearns, Squaw Peak, central Ari- 

 zona, May 9, 1S8S) : — General size and coloring intermediate between M. 

 formicivorus and M. formicivorus bairdi; throat less yellow than in 

 either of them ; bill shorter, more slender, and less arcuate than in either 

 of the other forms of M. formicivorus ; white striping of chest more than 

 in the Pacific coast form, less than in formicivorus. 



Young in First Plumage. (No. 5556, °. , juv.. Coll. E. A. Mearns, 

 Baker's Butte, Mogollon Mountains, central Arizona, July iS, 18S7) : — 

 Similar to adults, but lacking the black band across the fore part of crown, 

 the whole top of the head being red, in both sexes ; colors duller, with the 

 quill-feathers, neck and breast slightly brownish; pectoral band broader, 

 with less of the white striping; black streaks of sides less sharply defined, 

 having a blurred appearance. 



Habitat. — Southwestern United States, southward through the 

 mountainous portions of western Mexico. 



Measurements* of Mclanerpcs formicivorus aculeatus from Arizona. 



Length 



Alar expanse 



Wing 



Tail 



Culmen (chord) 



Tardus 



Middle toe and claw 



17 MALES. 



BOTH SEXES 



(34 specimens). 



*In millimetres; taken in the flesh by the author. 



