42 PACIFIC COAST AVIFAUNA No. 10 



175. . Nuttallornis borealis (Swainson) 



OLIVE-SIDED FLYCATCHER. 



Synonym Contopns borealis. 



Status Common in summer from the Transition zone upward, in the higher 

 mountains north of the Mogollon Plateau ; recorded as breeding on the San Fran- 

 cisco, White, and Mogollon mountains. During the migrations it is quite gen- 

 erally distributed. 



176. Myiochanes pertinax pallidiventns (Chapman). ,. .. 



COUES FLYCATCHER. 



Synonyms Contopns pcrtinax ; Contopus pertinax pallidircntris; Horizo- 

 pus pertinax pallidivcntris. 



Status Common summer visitant in the Transition zone of the mountains 

 of southeastern Arizona (Tluachuca, Santa Rita. Santa Catalina and White 

 mountains, Mount Graham, etc.), extending northward, in diminishing numbers, 

 to the Mogollon Mountains, where it was found breeding at Baker's Butte 

 (Mearns, i8f)oa, p. 256); casually to Fort Whipple: i specimen, August 20, 

 1864 (Coues, i866a, p. 60). 



177. Myiochanes richardsoni richardsoni (Swainson). 



WESTERN WOOD PEWEE. 



Synonyms Contopus richardsoni; Contopns vircns richardsoni; Ilorizopns 

 richardsoni; Contopus -I'diei. 



Status Common in summer in Upper Sonoran and Transition throughout 

 the state. During the migrations it is generally distributed. 



178. Empidonax difficilis diffieilis Baird. 



WESTERN FLYCATCHER. 



Synonym Empidonax flavircntris var. difficilis. 



Status A fairly common summer visitant, mostly in Transition, occurring 

 in all the higher mountain ranges. Abundant and of general distribution during 

 the migrations. 



179. Empidonax trailli trailli (Audubon). 



TRAILL FLYCATCHER. 



Synonyms Empidonax pnsillus; Empidonax trailli var. pnsillits. 



Status Probably fairly common in summer along most of the wooded 

 streams in the lower valleys, though found actually breeding at but a few points : 

 Tucson, Fort Whipple, San Pedro River, Santa Cruz River. During the migra- 

 tions it is abundant and generally distributed. 



180. Empidonax hammondi (Xantus). 



HAMMOND FLYCATCHER. 



Status A migrant, abundant and generally distributed throughout the state. 

 It is not known to breed anvwherc in Arizona. 



