_Dendroica nigrescens_: Black-throated gray warbler 275 Habits 275 Distribution 281 _Dendroica towndsendi_: Townsend's warbler 282 Habits 282 Distribution 290 _Dendroica virens virens_: Northern black-throated green warbler 291 Habits 291 Distribution 304 _Dendroica virens waynei_: Wayne's black-throated green warbler 308 Habits 308 _Dendroica chrysoparia_: Golden-cheeked warbler 316 Habits 316 Distribution 321 _Dendroica occidentalis_: Hermit warbler 321 Habits 321 Distribution 328 _Dendroica cerulea_: Cerulean warbler 329 Habits 329 Distribution 335 _Dendroica fusca_: Blackburnian warbler 337 Habits 337 Distribution 347 _Dendroica dominica dominica_: Eastern yellow-throated warbler 349 Habits 349 Distribution 358 _Dendroica dominica albilora_: Sycamore yellow-throated warbler 359 Habits 359 _Dendroica graciae graciae_: Northern Grace's warbler 363 Habits 363 Distribution 367 INTRODUCTION This is the nineteenth in a series of bulletins of the United States National Museum on the life histories of North American birds. Previous numbers have been issued as follows: 107. Life Histories of North American Diving Birds, August 1, 1919. 113. Life Histories of North American Gulls and Terns, August 27, 1921. 121. Life Histories of North American Petrels and Pelicans and Their Allies, October 19, 1922. 126. Life Histories of North American Wild Fowl (part), May 25, 1923. 130. Life Histories of North American Wild Fowl (part), June 27, 1925. 135. Life Histories of North American Marsh Birds, March 11, 1927.