Head and back bluish gray; rump and under parts bright yellow: tail very long.
M. Boarula, Temm. Man. d'Orn. torn. I. p. 257. Gray Wagtail, Mont. Orn. Diet, and Supp. Selb. Illust. vol. I. p. 253. pl. 49. f. 2. Bew. Brit. Birds, vol. i. p. 228.
Entire length seven inches nine lines: length of the bill (from the forehead) five lines, (from the gape) seven lines and a half; of the tarsus ten lines; of the hind toe, claw included, six lines; of the tail three inches ten lines; from the carpus to the end of the wing three inches one line and a half.
(Summer plumage). Head, neck, back, and scapulars, bluish gray: above the eyes a pale streak: throat black: rump, and under parts, bright yellow, the former tinged with green: quills and six middle tail-feathers grayish black, more or less edged with yellowish white; outer tail-feather entirely white; the two next white, with a part of the outer web black: feet dusky brown. (Winter plumage). Throat yellowish white: under parts of a paler yellow. Obs. Female at all times paler than the male. (Egg). White, nearly covered with reddish yellow brown, varying in intensity: long. diam. eight lines and a half; trans, diam. seven lines.
A regular winter visitant in the southern parts of the kingdom, but in the northern a summer visitant. Habits and nidification very similar to those of the last species. Is said to have two broods in the year, the first of which is generally fledged about the end of May.
** Hind claw elongated; but slightly curved.