young birds which had been taken on Burhou; these still had down on them when I got them, and were then difficult to tell from young Herring Gulls. The distinctions I have mentioned in my note of that bird were, however, apparent, and the slight difference in the colour of the legs is perhaps more easily seen in the live birds than in skins which have been kept and faded into "Museum colour." It is some time, however, before either bird assumes the proper colour, either of the legs or bill, the change being very gradual. After the autumnal moult of 1878, however, the dark feathers of the mantle almost entirely took the place of the brownish feathers of the young birds; the quills, however, have still (February, 1879) no white tips, and the tail-feathers are still much mottled with brown. One Lesser Black-back, which I shot near the Vale Church on the 17th of July, 1866, is perhaps worthy of note as being in transition, and perhaps a rather abnormal state of change considering the time of year at which it was shot; it was in a full state of moult; the new feathers on the head, neck, tail-coverts, and under parts are white; the tail also is white, except four old feathers, two on each side not yet moulted, which are much mottled with brown. The primary quills had not been moulted, and are quite those of the immature bird, with no white tip whatever. All the new feathers of the back and wing-coverts are the dark slate-grey of the adult, but the old worn feathers are the brownish feathers of the young bird; these feathers are much worn and faded, being a paler brown than is usual in young birds. The legs and bill are also quite as much in a state of change as the rest of the bird. Before finishing this notice of the Lesser Black-back I think it is worth while to notice that it selects quite a different sort of breeding-place to the Herring Gull; the nests are never placed on ledges on the steep precipitous face of the cliffs, but amongst the bracken and the flat rocks, as at Burhou, the only rather steep rock I have seen any nests on was at the Amfrocques, but there they were on the flattish top of the rock, and not on ledges on the side. Professor Ansted includes the Lesser Black-backed Gull in his list, but only marks it as occurring in Guernsey. There is one specimen in the Museum.