This species, in general appearance, apparently comes nearer to _P. trochilus_ than to any other of its congeners. It is, however, more olivaceous-green above, and more yellow beneath, and has a distinct band across the wing. The superciliary light stripe is more distinct and longer; the bill and legs are darker, and the toes not sensibly different in color from the tarsus. The proportion of the quills is much the same, except that the interval between the tips of the fifth and sixth quills is greater, and the second is almost inappreciably longer than the latter, not reaching nearly midway between the two. The first or spurious quill is rather shorter. A single specimen of this species was obtained August 16, 1866, on St. Michael’s Island, in Norton Sound, Alaska, by Mr. Charles Pease. Mr. Bannister met with no other specimen in that locality, and from this it is inferred that this is not an abundant species there. It was described as a new species under the name of _P. kennicottii_ (Baird), but has been ascertained by Mr. Tristram, to whom it was sent for examination, (Ibis, 1871, p. 231,) to be identical with _P. borcalis_ of Blasius. Dr. Blasius also states (Naumannia, 1858, p. 303) that a specimen of this species has been obtained on the island of Heligoland, showing it to be also an accidental visitant to Western Europe. HABITS. Mr. R. Swinhoe, who describes this among the birds of Formosa as _P. sylvicultrix_, states it to be a summer visitant to Southern China, passing in large numbers through Amoy in its autumnal migrations southeastward, probably to the Philippine Islands, touching at Southwestern Formosa and Twaiwanfoo, where he found them abundant. This was for a few days in October, but he neither saw any before nor afterwards, nor did he meet with any at Tamsuy (Ibis, 1863, p. 307). The same writer (Ibis, 1860, p. 53) speaks of this bird as very abundant in Amoy during the months of April and May, but passing farther north to breed. We have no information in reference to its habits, and nothing farther in regard to its distribution. As it bears a very close resemblance to the Willow Wren of Europe, _P. trochilus_, it is quite probable that its general habits, nest, and eggs will be found to correspond very closely with those of that bird. The European warblers of the genus _Phyllopneuste_ are all insect-eating birds, capturing their prey while on the wing, and also feeding on their larvæ. They frequent the woodlands during their breeding-season, but at all other times are much more familiar, keeping about dwellings and sheepfolds. The _P. trochilus_ is a resident throughout the entire year in Southern Europe and in Central Asia. That species builds at the foot of a bush on the ground, and constructs a domed nest with the entrance on one side. Their eggs are five in number, have a pinkish-white ground, and are spotted with well-defined blotches of reddish-brown, measuring 0.65 by 0.50 inch, and are of a rounded oval shape.