Range.--Western United States; breeds east to about Long. 100°, north to Assiniboia, southern Alberta, southern British Columbia, west to the Pacific; winters south of United States; to Central America.
=448. Cassin Kingbird= (_Tyrannus vociferans_). L. 9. _Ads._ Throat and breast _dark gray_, belly yellow; tail black, outer web of outer feather not wholly white; above as in No. 447. _Yng._ With no crown-patch. _Notes._ Less noisy than No. 447. (Bendire.)
Range.--Western United States, northwestern Mexico and north through Rockies, from western Texas, New Mexico and Arizona, to southern Wyoming; in California north to San Benito County; winters south of United States to Central America.
=449. Derby Flycatcher= (_Pitangus derbianus_). L. 11. _Ads._ Back brown, wings and tail externally rusty; a yellow crown-patch; forehead, line over eye and across nape white; throat white, below yellow. _Notes._ _Kiskadee_, repeated. (Richmond.)
Range.--Northern South America; breeds north as far as Lower Rio Grande, Texas.
=451. Sulphur-bellied Flycatcher= (_Myiodynastes luteiventris_). L. 8. Below sulphur streaked with black; tail largely rusty brown; a yellow crown-patch; inner wing feathers widely margined with whitish; back grayish brown streaked with dusky. _Yng._ With no crown-patch. _Notes._ A screech, like squeaking of a wagon wheel, and a single note. (Poling.)
Range.--Central America; breeds north as far as southern Arizona.
=452. Crested Flycatcher= (_Myiarchus crinitus_). L. 9. Inner webs of all but middle tail-feathers rust-brown. _Ads._ Throat and breast gray, belly _bright_ sulphur; back grayish _olive-green_; greenest above and yellowest below of our larger _Myiarchi_. _Notes._ Loud, chuckling, grating whistles.
Range.--Eastern North America; west to the Plains; breeds from Florida and Texas north to New Brunswick and Manitoba; winters from southern Florida south to northern South America.
=453. Mexican Crested Flycatcher= (_Myiarchus mexicanus_). L. 9.2; W. 4. Inner webs of all but middle tail-feathers rust brown. _Ads._ Throat and breast gray, belly sulphur, both paler than No. 452; back grayish brown, with little or no green tinge. _Notes._ Resemble those of No. 452. (Merrill.)