40 U. S. P. R. R. EXP. AND SURVEYS ROUTE TO CALIFORNIA. 



DENDROICA AESTIVA, G m e 1 i n .Yellow-Poll Wood Warbler. 



Sylvicola aestiva, RICH. & Sw. F. Bor. Am. vol. II, p. 211. AUD. B. of A. Oct. vol. II, p. 50, pi. 83. 

 Dendroica aestiva, BAIRD, Gen. Rep. IX, 282. 



Abundant over the entire country. 



DENDROICA NIGRESCENS, T o w n s .Black-throated Gray Warbler. 



Sylmcola nigrescens, AUD. B. of A. Oct. Vol. II, p. 62, pi. 114. 



Sylvia nigrescens, AUD. Fol. pi. 395. TOWNSEND, Jour. Acad. N. Scien. Phil. vol. VII, p. 191. 



Sylvia halseyii, G. P. GIRAUD, 16 New Species of N. A. Birds, fig. 1. 



Dendroica nigrescens, BAIRD, Gen Rep. IX, 270. 



I obtained, in 1852, a few specimens of this species near Sacramento City and also on the range 

 of mountains which divide the Calaveras and Mokelumne rivers. During this expedition, 

 in the month of October, I met with but a single individual in the mountains adjoining the 

 summit of the Tejon Pass. It was then migrating southward with several other small species 

 of birds and gleaning its insectivorus food from the topmost branches of some tall oaks. The 

 notes of this bird closely resemble those of a locust. 



TRICHAS TOLMIEII, To wns . Tolmie s Warbler. 



Irichas macgillivrayii, AUD. B. of A. Oct. vol. II p. 74, pi. 100. 



Sylvia tolmieii, TOWNS. Jour. Acad. N. Scien. Phil. vol. VIII, p. 149. IB. Townsend s Narrative, p. 343. 



Geothlypis macgillivrayi, BAIRD, Gen. Rep. IX, 244. 



A beautiful and somewhat rare species, affording but few opportunities for the study of its 

 habits, as it retires amidst the deep shady swamps and brushwood, from whence it seldom makes 

 its appearance. 



TRICHAS DELAFIELDII, Aud. Delafield s Yellow-throat. 



Trichas delafieldii, AUD. B. of A. Oct. vol. II, p. 81, pi. 103. IB. Synop. p. 65. 

 Sylvia delafieldii, AUD. Orn. Biog. vol. V, p. 307. 

 Gtothlypis trichas, BAIRD, Gen. Rep. IX, 241. 



Abundant and like its closely allied species, the Trichas marilandicus, haunts the low thickets 

 in the vicinity of water, in which localities it seeks its food on the ground, seldom appearing 

 above the tops of the bushes. It incubates in the country, for though I was not fortunate 

 enough to discover its nest, I shot on several occasions the bird in its young plumage. 



HELMINTHOPHAGA GEL ATA, S a y .Orange-crowned Warbler. 



IMinaia celaia, AUD. B. of A. Oct. vol. II, p. 100, pi. 112. 



Sylvia celaia, AUD. B. A. Fol. pi. 178. BONAP. Am. Orn. vol. I, p. 45, pi. 5, fig. 2. SAY, Long s Exped. to Rocky 



Mts. vol. I, p. 169. NUTT. Orn. vol. 1, p. 413. 

 Iltlminthophaga celata, BAIRD, Gen. Report IX, 257. 



This bird is plentiful all over the country, having procured it in northern California, in the 

 Tejon valley, and on the Colorado river, near Fort Yuma. It is migratory in its habits, but 

 some few pairs incubate near the summits of the highest mountains in the mining regions. 



CERTHIA AMERICANA, Bon .Brown Tree Creeper. 



Certhia familiaris, WILS. Am. Orn. vol. I, p. 122, pi. 8, fig. 1. AUD B. of A. Oct. vol. II, p. 109, pi. 115. IB. Fol. 



pi. 415. 

 Cerihia americana, BONAP. Compar. List. p. 11. BAIKD, Gen. Hep. IX, 372. 



Abundant in California, especially in the mountainous districts. 



