128 PROCEEDINGS OF THE ACADEMY OF 



nifescent on wings and less observably so on tail. Pectoral aspect different 

 from fuscescens, the spots narrow and cuneate, sharplj^ defined, and arranged 

 in longitudinal series ; in color they are a little darker than the crown. 



This well marked and perfectly distinct species is to be compared with 

 swainsonii, not with fuscescens, as has generally been done ; the latter, except 

 in shade of colors, it scarcely resembles at all ; still greater evidence that 

 such is its affinity is that the T. ustulatus builds its nest on a tree, and lays a 

 spotted egg, like swainsonii, while fuscescens nests on or near the ground, per- 

 haps never in a tree, and lays a plain blue egg. 



TURDUS SWAINSONII. 



Tardus swainsonii, Cabanis, Tschudi, Fauna Peruana, 1844, 46, 188 — Baird, 

 Birds N. Am. 1858, 216. — Tardus (^Hylocichla) swainsonii, Baird, Rev. Am. 

 Birds, i, 1864, 19. 



Sp. ch. Olive above dark and pure, of a continuous shade throughout; in 

 extreme western examples, with a clear dark greenish tint. A very broad, 

 conspicuous ring of buff around the eye, running forward over the lore, and 

 a very decided tinge of the same on breast. Pectoral spots well defined, 

 deltoid, becoming more transverse posteriorly, dull black. 



Specimens examined from the northern regions (Gt. Slave Lake, Mackenzie's 

 Eiver and Yukon) to Guatemala; from Atlantic States to East Humboldt 

 Mts., Nevada, California, and from intervening localities. The extremes of 

 variation are the brownish olive of eastern and clear dark greenish olive of 

 remote western specimens. There is no observable difference between a 

 Guatemalan skin and one from Ft. Bridger, Utah. 



TuRDUS ALICIA. 



Tardus alicise, Baird, Birds N. Am. 1858, 217, pi. 81, fig. 2— Cones, Pr. Ac. 

 Nat. Sciences, Phil. Aug. 1861, 217. — Tardus [Hylocichla) alicise, Baird, Rev. 

 Am. Birds, I, 1864, 21. 



Sp. ch. The olive above, similar to that of swainsonii, is scarcely more green- 

 ish, but is generally decidedly darker, and often with the slightest possible 

 tinge of rich sepia or snuff brown, this becoming gradually more appreciable 

 toward the tail; in these typical examples this tint is quite peculiar; when 

 the shade approaches that of swainsonii it is generally when there are other 

 unmistakable evidences of hybridism. There is in this species not a trace of 

 a lighter loral stripe and orbital ring, so characteristic of swainsonii, this whole 

 region being grayish, scarcely different from the cheek; with the exception of 

 the lack of decided buffy tinge, the pectoral aspect is that of sivainsonii. 



A specimen from Costa Rica is undistinguishable from typical examples 

 from the eastern U. S. 



This bird and the robin are the only species of our thrushes that cross the 

 Arctic circle to any distance, or reach the shore of the Arctic Ocean. It oc- 

 curs in from Labrador, all round the American coast, to the Aleutian Islands, 

 everywhere bearing its specific character as indicated above. It is extremely 

 abundant on and near the Arctic coast, between the mouth of the Mackenzie's 

 River and the Coppermine, more than 200 specimens (mostly with their eggs) 

 having been sent thence to the Smithsonian Institution by Mr. MacFarlaue. 

 In all this number there was not a single bird that had any approach to the 

 characters of T. swainsojiii, as just given. From the Slave Lake region, on the 

 other hand, T. swainsonii -vf&a received in nearly the same abundance, and un- 

 mixed during the breeding season with T. alicix. 



TdRDUS PAIiLASI. 



Turdas pallasi, Cabanis, Wieg. Arch. 1847, i, 205 — Baird, Birds N. Am. 1858, 

 212. — Turdus [Hylocichla) pallasi, Baird, Rev. Am. Birds, 1, 1864, 14. 



Sp. ch. Olive above almost exactly that of ustulatus. Rufous of the tail, 

 upper tail coverts and lower part of rump, uniform. Olivaceous of neck con- 

 tinuing along sides; spots on breast sharply defined, and nearly pure black. 



[June, 



