lengthened, without strong reflexes on the tips, less compact, and less strongly pigmented. The tail in the common Marsh Tits is almost straight, only the lateral pair being a little shorter. The tail in P. salicarius and allies is strongly graduated, at least the two lateral pairs being much shortened. There are also differences in colour, form, and size of bill, et cet.; but they are not so easy to see, and I will not dilate upon them at length. With regard to P. salicarius, it may be added that it differs from P. borealis considerably in size, form of bill, colour of flanks, colour of edges of wings, and of the entire upper side. It is, however, as P. borealis is not known to occur in Great Britain, more important for British ornithologists to distinguish it from the ordinary British Marsh Tit generally called P. palustris dresseri, and I may therefore repeat that it differs from the latter chiefly in the colour and structure of the feathers of the crown, the form of the tail, and the more rufous flanks and more brownish edges of the secondaries, besides its call-note being very different.
P. salicarius, although described as long ago as 1831, has been lost sight of for a long time, and only quite recently our young friends on the Continent, Kleinschmidt and Prazak, have rediscovered it. I myself came across it long ago in the willow thickets of the Lower Rhine near Wesel, and was at once struck by the colour of its crown, which, however, I thought erroneously to be due to its being a young summer bird. No credit therefore is due to my observation, which was lost through my travelling far away into Africa and India, which ended for a time my studies of German birds. The specimen in question, which somehow lost its original exact label, was later given by me to the British Museum in exchange, and is there now. P. salicarius evidently inhabits dark willow thickets and other swampy woods, so dense that the sun hardly ever reaches the ground in them. It is found on the Rhine between Worms and Bingen and near Wesel, and at Renthendorf in Saxony. When Mr. Kleinschmidt was in England last autumn he recognized two British skins, from Hampstead, in the British Museum, as P. salicarius, and as these birds were just then in fairly good plumage, I at once tried to procure some specimens, but only succeeded in getting three from Finchley.
