28 Nelson North American Mainland Myiarchus. 



Inner webs of tail feathers mainly rufous inquietus p. 38. 



Inner web of tail feathers mainly dusky yucatanensis p. 41. 



Inner web of outer tail feather usually entirely rufous on basal 



two-thirds, with outer third more or less broadly tipped 



with dusky 



Bill smaller, slenderer; color darker - cinerascens p. 33. 



Bill larger, broader; color paler - pertinax p. 36. 



Bill flattened with depth at angle of gonys decidedly less than width at 



same place (subgenus Onychopterus] 

 Tail feathers usually distinctly edged on one or both webs with rufous 



or cinnamon 



Tail feathers distinctly edged on both webs with rufous or cinnamon 



Crown conspicuously darker than back (black or blackish) 



Crown sooty black - - nigricapillus p. 44. 



Crown clove brown - later encei p. 42. 



Crown appreciably darker than back (usually between olive and 



sepia brown) - querulus p. 47. 



Tail feathers not at all or but slightly edged on inner webs with 



rufous or cinnamon 

 Back greenish or greenish olivaceous 



Back greenish, crown intensely black bangsi p. 45. 



Back greenish olivaceous, crown bistre brown 



platyrhyncJms p. 45. 

 Back grayish olivaceous or hair brown 



Back grayish olivaceous; inner webs of tail feathers usually 



not edged with rufous olivascens p. 48. 



Back hair brown; inner webs of tail feathers usually slightly 



edged with rufous - tresmarice p. 49. 



Tail feathers not edged on either web with rufous; no rufous edgings 



on wings; crown dull black - nigriceps p. 49. 



DESCRIPTIONS OF SPECIES AND SUBSPECIES. 

 Genus Myiarchus Cabanis. 



1845. Myiarchus Cabanis, in Tschudi, Fauna Peruana, Aves, 1845, p. 

 152. Type Muscicapa ferax Gmelin. 



Typical Myiarchus is characterized by a rounded and proportionately 

 deep bill; the depth at angle of the gonys nearly or quite equaling its 

 width at the same place. It includes the majority of the species in 

 this paper, viz., M. ferox panamensis, M. crinitus, M. c. residuus, M. mex- 

 icanus, M. m. magister, M. cinerascens, M. c. pertinax, M. nuttingi, M. n. 

 inquietus, M. brackyurus, and M. yucatanensis. 



