452 NUliTIl AMERICAN BIRDS. 



cuiitiiiiiL'il two e«'L's, exactly rL'senibliiij:? those of the T. colubris, and measur- 

 iu'^ .51 by .'.>2 of an inch. 



Afterwards Mr. W. W. Holden obtained a specimen in the Colorado Val- 

 \ev, March I'O. 



Mr. J. K. Lord, one of the English commissioners of the Northwestern 

 liouiidary Survey, met with this si)eeies near his camping-place on the west- 

 ern slope of the liocky Mountains. This was near a lake, by the margin of 

 which, with otlier trees, grew a number of the black birch. On these trees 

 he found a sweet gummy saji exuding plentifully from splits in the bark, 

 and on this saj) hosts of insects, hn-ge and small, were regaling themselves. 

 As the sap was very sticky, nundiers of the smaller winged insects were 

 trap}>ed in it. Busily employed in picking off and devouring these captive 

 insects were several very sombre-looking liumming-Birds, poising them- 

 selves over the tlowers, and nii)ping off, as with delicate forceps, the im- 

 ])risoned iusects. V\u)n securing one of these birds, he ascertained that it 

 bel()nge<l to this s])ecies. This was ])retty satisfactory proof that they are 

 insect-eaters. N(»t only on this occasion, Init many times afterwards, ^Ir. 

 Lord saw tliis bird ])ick tlie insects from the tree; and the stomachs of those 

 he killed, on being opened, were filled with various kinds of winged insects. 

 He found this Itird lingering around lakes, pools, and swamps, where these 

 birches grow. Thev u:enerallv l.»uild in the birch or alder, selecting the fork 

 of a brancli high up. 



This species beais a very close resemblance in size, appearance, and mark- 

 ings, to tlie common eastern species, bnt is readily distinguishable by the 

 ditferencc in tlie color of tlie chin and the shape of the tail. 



In tlie spring of IS.Il, on a trip to Sonora, Mexico, Dr. Heermann found 

 these birds abundant in the arid country around (luaymas, where amid the 

 scanty vegetation they had constructed their nests in the month of Aiuil. 

 He also afterwards found tliem on Dry Creek and the Cosnnmes liiver. 



According to the observations of Mr. Bidgway, this s})ecies has (piite an 

 extended distributi<»n in the West. He found it in yarvinti abundance from 

 the Sacramento Valley, in California, to the Wah.satch and Uiniah Moun- 

 tains in Utah. 



At Sacramento it was more abundant than the C. anna, nesting in the 

 door-yards and in gar<lens, ijut particularly in the thick co])ses of small oaks 

 in the outskirts of the city. In tlie (rreat Basin it associated with the 

 Schisphoru.s rnfcs in the western portion, and with S. platifccrcn^i to the east- 

 ward, nesting everywhere, from tlie lowest valleys to a height of eight or 

 nine thousand feet in the mountains. 



