14 NORTH AMERICAN BIRDS. 



the iMackenzie Eiver and tlie Coppermine, more than 200 specimens 

 (mostly with their eggs) having been sent thence to the Smithsonian 

 Institution by ilr. MacFarlane. In all this number tliere was not a 

 single bird that had any approacli to the characters of I", swaiiisoni, as 

 just given. From the Slave Lake region, on the other liand, T. swainsoni 

 was received in nearly the same abundance, and immixed during tlie 

 breeding season with 1\ ulicim. 



Turdus swainsoni, Cakaxis. 



OUVE-BACKED THEUSH; SWAINSON'S THKUSH. 



Turdus swainsoni. Cab. Tseliudi, Fauna I'eniana, lS4-l-4(i, 188. — ?ScLATEK & Salvin, 

 Ibis, 1859, 6 (Guatemala). — Scl.\ter, P. Z. S. 1858, 451 (Ecuador); 1859, 326.— 

 IB. Catal. 1861, 2, no. 11. — Baikd, Birds N. i\xn. 1858, 216; Rev. Am. B., 1864, 19. 

 — GuNDLACii, Cab. .Jour. 1861, 324 (Cuba). — Ib. Repert. 1865, 229. — Pelzf.ln, Orn. 

 Brazil, II. 1868, 92 (Marambitanas, Feb. and March). — La wr. N. Y. Lye. IX, 91 

 (Costo Rica). — RiDGWAY. — SIayxard. — Samuels, 152. —Cooper, Birds Cal. 6. — 

 Dall & Bannister. Turdus minor, G.melin, Syst. Nat. I, 1788, 809 (in part). 

 Turdus olivaceus, Giraub, Birds L. Island, 1843-44, 92 (not of LiNS.). (') Turdus 

 minimus, Lafre.sxaye, Rev. Zoiil. 1848, 5. — Sclater, P. Z. S. 1854, 111. — Bryant, 

 Pr. Bost. Soc. VII, 1860, 226 (Bogota). — Lawre.nce, Ann. N. Y. Lye. 1863. (Birds 

 Panama, IV, no. 384.) 



Sp. Ciiau. Upper part.s uniform olivaceous, with a decided shade of green. Tlie fore 

 part of breast, the throat and chin, pale brownish-yellow ; rest of lower parts white ; 

 the sides washed with brownish-olive. Sides of the throat and fore part of the breast 

 with sub-rounded spots of well-defuied brown, darker than the back ; the rest of the 

 breast (except medially) with rather less distinct spots that are more olivaceous. Tibiie 

 yellowish-brown. Broad ring round the eye, loral region, and a general tinge on the 

 side of the head, clear reddish buff. Length, 7.00; wing, 4.15; tail, 3.10; tarsus, 1.10. 



Hab. Eastern North America ; westward to Humboldt Mountain and Upper Columbia; 

 perhaps occasionally straggling as far as California; north to Slave Lake and Fort Yukon ; 

 south to Ecuador and Brazil. Cuba, Gt:NDLAcn; Costa Rica, Lawr. 



Specimens examined from the northern regions (Great Slave Lake, jMau- 

 kenzie Elver, and Yukon) to Guatemala ; from Atlantic States to East 

 Humboldt Mountains, Nevada, and from intervening localities. Tlie ex- 

 tremes of variation are the brownish-olive of eastern and the clear dark 

 greenish-olive of remote western specimens. There is no observable dif- 

 ference between a Guatemalan skin and one from Fort Bridger, Utah. 



Hajbits. The Olive-backed Thrush, or " Swamp Eobin," has very nearly 

 the same habitat during the breeding season as that of the kindred species 

 with which it was so long confounded. Although Wilson seems to have 

 found the nest and eggs among the high lands of Northern Georgia, it is yet 

 a somewliat more northern species. It does not breed so far south as 

 Massachusetts, or if so, the cases must be exceptional and very rare, nor 

 even in Western IMaine, where the "Ground Swamp Eoljin" {T. pallasi) is 

 quite abundant. It only becomes common in tlie neighborhood of Calais. 



