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U. S. P. R. R. EXP. AND SURYEYS—ZOOLOGY—GENERAL REPORT. 
invaluable list of genera and sub-genera of birds, by G-. R. Gray, 1855, this section is left 
without a name, with Muscicapa nunciola , Wils., (“ Tyrannula fused”) as type, and with Tyran- 
nula, Sw., 1831, not of 1827, and Myiobius, Gray, 1847, not 1838, as synonymous. To this 
section Cabanis has applied the name of Aulanax, but in giving “ Tyrannula nigricans ” as the 
type, his name becomes a synonym of Sayornis, Bonaparte. 
It is possible that, if Bonaparte has presented a conspectus of the Tyrants in the Ateneo 
italiano or elsewhere, in 1854, or subsequently, he has not overlooked the present groups, but I 
am unable to determine this point. It only remains for the present to take the names of 
Cabanis, as quoted, namely, Contopus for the short-legged group, with Muscicapa virens, L., as 
type, and including also Muscicapa cooperi, Nut tall, Platyrliynclius cinereus, Spix, and Tyran¬ 
nula ardosiaca, of Lafresnaye, and Empidonax for the other one. 
CONTOPUS BOREALIS, Baird. 
v 
Olive-sided Flycatcher. 
Tyrannus borealis, Sw. & Rich. F. Bor. Am. II, 1831, 141 ; plate. 
Mijiobius borealis, Gray, Genera, I, 248. 
Muscicapa cooperi, Nuttall, Man. 1,1832, 282.— Aud. Orn. Biog. II, 1834, 422: V, 1839, 422 ; pi. 174.—In. Synopsis, 
1839, 41 .—Ib. Birds Amer. I, 1840, 212 ; pi. 58. 
Tyrannus cooperi, Bonap. List, 1838.— Nuttall, Man. I, 2d ed. 1840, 298. 
Contopus cooperi, Cabanis, Journal fur Ornithol. Ill, Nov. 1855, 479. 
Muscicapa inornata, Nuttall, Man. I, 1832, 282. 
Sp. Ch.—W ings long, much pointed ; the second quill longest; the first longer than the third. Tail deeply forked. Tarsi 
short. The upper parts ashy brown, showing darker brown centres of the feathers ; this is eminently the case on the top of the 
head ; the sides of the head and neck, of the breast and body resembling the back, but with the edges of the feathers tinged with 
grey, leaving a darker central streak. The chin, throat, narrow line down the middle of the breast and body, abdomen, and 
lower_tail coverts white, or sometimes with a faint tinge of yellow. The lower tail coverts somewhat streaked with brown in 
the centre. On each side of the rump, generally concealed by the wings, is an elongated bunch of white silky feathers. The 
wings and tail very dark brown, the former with the edges of the secondaries and tertials edged with dull white. The lower 
wing coverts and axillaries greyish brown. The tips of the primaries and tail feathers rather paler. Feet and upper mandible 
black, lower mandible brown. The young of the year similar, but the color duller ; the feet light brown. Length, 7.50 ; 
wing, 4.33 ; tail, 3.30 ; tarsus, .60. 
Hab. —Rare on the Atlantic and Pacific coasts of the United States. Not observed in the interior, except to the north. 
Found in Greenland. (Reinhardt.) 
This large and powerful “ Tyrannula” is eminent for the length of its wings, which reach 
beyond the middle of the tail and the coverts to within a little more than an inch of the tip. 
The primaries are considerably attenuated, and a little cut out on the inner web, towards the 
end. The longest quill exceeds the secondaries by about 1.80 inches. The depth of fork in the 
tail is nearly .30 of an inch. 
There is a very narrow edging of whitish to the first primary ; the outer web of the outer 
tail feather is pale brownish towards the edge. 
Specimens sometimes have a little more yellow beneath than that described. In some western 
skins the third quill is a little longer than the fourth. 
Hartlaub, in his list of the birds of Chile, quotes a Tyrannula cooperi , supposed to be identical 
with the present species. If it be the bird described as Tyrannula cooperi by Kaup, it is totally 
distinct and belongs to the genus Myiarchus, which see. 
