_Breeding range._--Lucy's warbler breeds =north= to southern Utah (Beaverdam Wash, Zion National Park; Calf Creek, Garfield County; and the San Juan River); and southwestern Colorado (Montezuma County near Four Corners). =East= to Colorado (near Four Corners); western New Mexico (Shiprock, possibly San Antonio, mouth of Mogollon Creek, and Redrock); southeastern Arizona (Bisbee); and northeastern Sonora (Moctezuma). =South= to northern Sonora (Moctezuma and Sáric); southern Arizona (Baboquivari Mountains, Menager's Dam, and Gadsden); and southern California (Picacho and Silsbee). =West= to southern California (Silsbee, Mecca possibly, and Chemehuevis Valley); western Arizona (Fort Mojave); and southwestern Utah (Beaverdam Wash). _Winter range._--The few available records place the winter home of Lucy's warbler in central western Mexico from Jalisco (Bolaños and Lake Chapala) to eastern Guerrero (Iguala). _Migration._--Few migration dates are available for a species with such a limited range. Early dates of arrival are: Arizona--Tucson, March 12. California--Mecca, March 29. Utah--St. George, March 23. A late departure date is: Arizona--Tombstone, October 3. _Egg dates._--Arizona: 58 records, April 22 to June 27; 30 records, May 2 to 21, indicating the height of the season. PARULA AMERICANA PUSILLA (Wilson) NORTHERN PARULA WARBLER PLATES 20, 21 HABITS I have always preferred the old name, blue yellow-backed warbler, as originally used by Wilson and Audubon, to the modern common name; it seems more descriptive of this dainty wood warbler. As to the origin of this newer name, Dr. Spencer Trotter (1909) writes: "The name 'parula' recently in vogue for the warblers of the genus _Compsothlypis_ is clearly borrowed from the old Bonaparte genus _Parula_ (diminutive of titmouse). The bird (_C. americana_) has appeared under various titles--'the Finch Creeper' of Catesby (I, 64), 'the various coloured little finch creeper' of Bartram (Travels, 292), and the 'Blue Yellow-backed Warbler' of Wilson, Audubon, and later authors." _Parula_ was extensively used as the generic name during the last century, and is now reinstated to replace _Compsothlypis_. The 1931 A. O. U. Check-List of North American Birds recognizes only two races of this species, the subject of this present sketch, _P. a. pusilla_, and the southern race, _P. a. americana_. The two forms together occupy a breeding range covering practically all of the United States east of the Great Plains, as well as parts of southern Canada, the type name being restricted to the birds breeding from the District of Columbia southward to Alabama and Florida.