Nelson North American Mainland Myiarchus. 33 



Myiarchus mexicanus magister Ridgway. 



ARIZONA CRESTED FLYCATCHER. 



1884. Myiarchus mexicanus magister Ridgway, Proc. Biol. Soc. Wash., 

 II, p. 90. 



Type locality. Camp Lowell, near Tucson, Arizona. Type No. 

 86,005, adult male, U. S. National Museum. 



Breeding range. From northwestern Chihuahua and southern Arizona 

 through western Mexico at least to the border of Chiapas. A partial 

 winter migration of northern birds extends as far as Guatemala, but 

 they are resident throughout a large part of their range. 



Zonal distribution. Lower Sonoran and Arid Tropical. 



Subspecific characters. Generally similar to and in some cases difficult 

 to distinguish in coloration from pale or faded specimens of true mexicanus, 

 but upper parts averaging grayer and less greenish; throat and breast 

 slightly paler ashy, and abdomen a trifle clearer or brighter yellow; size 

 averages decidely larger. 



Description of first plumage. Crown light seal brown; back dark hair 

 brown; upper tail coverts, broad border to outer webs and most of the 

 inner webs of tail feathers dull, dark cinnamon rufous; lesser wing 

 coverts tipped and tertials edged with pale vinaceous-buff; greater wing 

 coverts, secondaries and primaries broadly edged with dull rusty rufous, 

 paler than on borders of tail feathers; chin, throat and breast pearl gray 

 becoming darkest on breast; abdomen and under tail coverts pale prim 

 rose yellow. 



Measurements. Averages of twenty-three adult males: Wing, 108.9 

 (103-114); tail, 100.3 (93-106); culmen, 23.2 (22-25); tarsus, 25.4 (24.5-26). 



Averages of fifteen adult females: Wing, 106.7 (100-110); tail, 98.1 

 (94-102); culmen, 23 (22-25); tarsus, 25.1 (24-26). 



General Notes. Size is the only character by which magister can be 

 distinguished in a great majority of cases. Specimens from the type 

 region in southern Arizona are considerably larger than those from the 

 more southerly part of their range. Among the series from various sec 

 tions of the range, the one from the Tres Marias Islands averages the 

 smallest thus paralleling the relatively smaller size of the series of typi 

 cal mexicanus from Cozumel Island, off the coast of Yucatan. The types 

 of both "cooperi" and magister, are larger than average birds of the forms 

 they represent. 



Myiarchus cinerascens (Lawrence). 



ASH-THROATED FLYCATCHER. 



1851. Tyrannula cinerascens Lawrence, Ann. Lye. Nat. Hist. N. Y., 

 V, p. 121. September, 1851. 



Type locality. Western Texas. 



Breeding range. From the Dalles, Oregon, Cheyenne, Wyoming, and 



