Nelson North American Mainland Myiarchus. 37 



on basal half and becoming drab on distal third; inner webs of all but 

 middle pair plain cinnamon rufous except for a slender dusky line along 

 shafts near tips; wing coverts tipped with whitish and narrowly edged 

 with dull cinnamon; tertials edged with whitish; secondaries broadly 

 edged with cinnamon shading into broad edgings of light cinnamon 

 rufous on primaries; chin, throat and breast pale pearl gray; abdomen 

 and under tail coverts white with the faintest tinge of yellowish. 



Measurements. Averages of three adult males; wing, 94,6; tail, 89.3; 

 culmen, 19.6; tarsus, 23.3. 



General Notes. There is some difficulty in distinguishing specimens of 

 pertinax from faded ones of cinerascens, but the larger bill of pertinax and 

 its smaller size are usually sufficiently marked to distinguish them. In 

 fairly fresh plumage pertinax is distinctly grayer on the upper parts. The 

 exact limits between the ranges of the two forms is still undetermined. 



Myiarchus nuttingi Ridgway. 

 NUTTING'S FLYCATCHER. 



1882. Myiarchus nuttingi Ridgway, Proc. U. S. National Museum, V, 

 p. 394. 



Type locality. L& Palma, Costa Rica. Type No. 87,391, U. S. 

 National Museum. 



Breeding range. Costa Rica (La Palma): Honduras (on Nicaraguan 

 boundary 180 miles from Pacific Coast); Guatemala (Nenton); Mexico 

 (Ocozucuautla, Chiapas). Not migratory. 



Zonal distribution. Arid and Semi- Arid Tropical. 



Specific characters. Size small, wing not over 88 mm. ; back rather light 

 olivaceous brown; inner web of outer tail feather usually almost wholly 

 rufous. 



Description of fresh plumage. Crown olive brown with slightly darker 

 shaft lines, and borders of feathers with a shade of bistre brown; back 

 varying from slightly grayish to yellowish olive, usually with less 

 greenish than in brachyurus; upper tail coverts dark broccoli brown 

 shaded and slightly edged with dark raw umber; wing coverts and ter 

 tials broadly edged with dingy brownish white, palest on tertials; 

 primaries edged with dark rusty; outer web of outer tail feather light 

 drab; inner web usually plain rufous except a fine line of dusky along 

 shaft near tip, but sometimes with dusky line along shaft much as in 

 inquietus;ch\n, neck and breast dull gray, palest on throat; abdomen 

 and under tail coverts between primrose and sulphur yellow. Upper- 

 parts of worn specimens, like the type, are dull grayish, olive brown. 



Measurements. Averages of two adult males: Wing, 86.5 (85-88); tail, 

 84 (81-87); culmen, 17.2 (17-17.5); tarsus, 22 (21-23). 



Adult female (one specimen): Wing,, 85; tail, 84; culmen, 17; tarsus, 22. 



General notes. This species has a close general resemblance to 



