A second specimen (No. 45,910) differs in having ashy color of head obscured with olivaceous-brown; and the yellow on breast showing brownish bases. The light markings on the wings more distinct and whiter. Another bird (No. 45,913), taken on shipboard, about ninety miles west of St. Matthew’s Island, Behring’s Sea, August 10, 1866, appears to be of the same species, in autumnal dress. Here the upper colors are more brown; the lower parts yellowish-white tinged with brownish-fulvous across the breast and flank. Kamtschatkan specimens of the same stage of plumage are very similar. I am unable to distinguish this species from the Protean _Budytes flava_ of Europe and Asia. Many different races appear to be found throughout this wide circle of distribution, many of them more or less local, but the proportions and general character are the same in all, and the general tendency appears to be to unite all into one species. The sexes and ages of all the species, real or supposed, vary very much, and, in the absence of a large series, I can throw no light upon the obscurities of the subject. I cite above the latest general work on the birds of Europe, in which will be found the principal synonymes. The specimens from Alaska submitted for examination to Mr. H. B. Tristram were identified by him as the _B. flava_. HABITS. The Gray-headed Wagtail of Europe finds a place in the fauna of North America as a bird of Alaska, where specimens have been obtained, and where it is, at least, an occasional visitant. It is not a common bird of the British Islands, where it is replaced by a closely allied species. Only seven or eight instances of its occurrence were known to Mr. Yarrell. On the continent of Europe it is quite an abundant species, inhabiting wet springy places in moist meadows, and frequenting the vicinity of water and the gravelly edges of rivers. It is numerous in all the central portions of Europe. It has also an extensive northern and eastern geographical range, appearing in Norway and Sweden as early as April and remaining there until September. Linnæus met with it in Lapland on the 22d of May. It occurs in Algeria, Nubia, and Egypt. Mr. Gould has received it from the Himalayas, and Temminck gives it as a bird of Japan. According to Degland, this bird is a very abundant species in France, where it nests on the ground in the cornfields, in open fields, meadows, and amidst the standing grain. It lays from four to six eggs, of a brownish-yellow on a reddish-white ground, profusely covered with fine dots of reddish-gray, which are more or less confluent. A few zigzag lines of dark brown or black are found on the larger end. They measure .63 of an inch in length and .55 in breadth. Its food is flies, moths, small green caterpillars, and aquatic insects.