°Sg4 j Richmond and Knowlton on Montana Birch. 3^7 



left the vicinity of their breeding grounds to gather in larger squads on 

 the marshes of the Potomac, and many of them have, even by the middle 

 of July, begun to migrate down the river. Migratory birds are, however, 

 noted in the vicinity of Washington through most of September. 



85. Ampelis cedrorum. Cedar Waxwing. — Common. 



S6. Lanius ludovicianus excubitorides. White-rumped Shrike. — 

 Common in the valleys. A single Shrike was also noted in the moun- 

 tains in September. It was very likely L. borealis. 



87. Vireo gilvus. Warbling Vireo. — Common in the willows and 

 cottonwoods along streams in the valleys. 



SS. Helminthophila celata. Orange-crowned Warbler. — Two 

 specimens were secured at low elevations September 2 and 15. 



S9. Dendroica aestiva. Yellow Warbler. — Common. 



90. Dendroica auduboni. Audubon's Warbler. — Very common 

 during September both in the mountains and in the valleys. Breeds in 

 the mountains; numbers were observed at Mystic Lake late in July. 



91. Geothlypis macgillivrayi. Macgillivray's Warbler. — Common ; 

 breeds. 



92. Geothlypis trichas occidentalis. Western Yellow-throat. — 

 Very common. 



93. Sylvania pusilla pileolata. Pileolated Warbler. — Very 

 common from the middle of August until late in September, in the 

 valleys. 



94. Setophaga ruticilla. American Redstart. — Common in the 

 valleys. 



95. Anthus pensilvanicus. American Pipit. — Very common in the 

 fall. This species made its appearance toward the end of September, 

 mingling freely with the Horned Larks, which were arriving in large 

 numbers at that time. 



96. Cinclus mexicanus. American Dipper. — Generally distributed in 

 the mountain region. 



97. Oroscoptes montanus. Sage Thrasher. — One immature bird 

 secured, and another seen at low elevations. 



98. Galeoscoptes carolinensis. Catbird. — Common in the valleys. 



99. Salpinctes obsoletus. Rock Wren. — Quite abundant. Young 

 birds were plentiful during August. 



100. Troglodytes aedonaztecus. Western House Wren. — Common. 

 A nest found in a dead stump in a cottonwood thicket August 13, 

 contained four half-fledged young. 



101. Certhia familiaris montana. Rocky Mountain Creeper. — A 

 specimen shot September 23, in Jefferson Valley, was the only one seen. 



102. Sitta carolinensis aculeata. Slender-billed Nuthatch. — 

 Uncommon ; but found breeding at several places in the mountains. 



103. Sitta canadensis. Red-breasted Nuthatch. — Two specimens 

 obtained at low elevations in September. These specimens, and others 

 from the Mississippi Valley westward, are somewhat brighter on the under- 



