The eggs, which are four or five in number, exhibit noticeable variations in size, shape, and shades of coloring, bearing some resemblance to those of _T. ustulatus_ and to the eggs asserted to be those of _T. nanus_, but are sufficiently distinct, and are still more so from those of _T. aliciæ_. They range in length from .83 to .94, with a mean of .88, their mean breadth is .66, the maximum .69, and the minimum .63. Their ground color is usually bluish-green, sometimes light blue with hardly a tinge of green, and the spots are of a yellowish-brown, or russet-brown, or a mixture of both colors, more or less confluent, with marked variations in this respect. Turdus swainsoni, var. ustulatus, NUTTALL. OREGON THRUSH. _Turdus ustulatus_, NUTTALL, Man. I, 1840, 400 (Columbia River).—BAIRD, Birds N. Am. 1858, 215, pl. lxxxi, fig. 1.—IB. Rev. Am. B. 1864, 18.—COOPER & SUCKLEY, P. R. Rep. XII, II, 1860, 171.—RIDGWAY, Pr. A. N. S. Philad. 1869, 127.—DALL & BANNISTER, Tr. Chic. Acad.—COOPER, Birds Cal., 5. SP. CHAR. General appearance of _fuscescens_, but with pattern of _swainsoni_; the buff orbital ring as conspicuous as in latter. The olive above is more _brown_ than in this, and less yellowish than in _fuscescens_, becoming decidedly more rufescent on wings and less observably so on tail. Pectoral aspect different from _fuscescens_, the spots narrower and cuneate, sharply defined, and arranged in longitudinal series; in color they are a little _darker_ than the crown. Length, 7.50; wing, 3.75; tail, 3.00; tarsus, 1.12. HAB. Pacific Province of United States. Tres Marias Isl., Guatemala (winter), Mus. S. I. This well-marked race is to be compared with _swainsoni_, 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 _swainsoni_, while _fuscescens_ nests on or near the ground, perhaps never in a tree, and lays a plain blue egg. The song of the present bird is also scarcely distinguishable from that of _swainsoni_. Upon the whole, we see no reason why this should not be considered as a Pacific Province form of the _Turdus swainsoni_; at least it becomes necessary to do so, after referring to _T. pallasi_ as geographical races, the _T. auduboni_ and _T. nanus_.