8. BICKNELL on the Nesting of the Red Crossbill. severity, during which most of our boreal birds appeared in greater numbers, and extended their range further to the southward than for many winters before. At Riverdale, New York City, Red Crossbills were first observed in 1874 on November 3 (a small flock). They remained apparently but a few days, but reappeared in larger num- bers about a month later, and thereafter during the ensuing winter were constantly present in small roving flocks. At one locality, in particular, they were almost always to be found. This was about several private residences overlooking the river, whose grounds, abounding with various species of ornamental evergreens and co- nifers, especially larches and the Norway spruce (Abies excelsa), seemed to offer them especial attractions. Here as the winter waned the birds became none the less common, and in the mild mornings of early spring-time this species, as well as Phacicola enucleator, would often be found in full song, frequently on the same tree. As I now recall them, the song of the Grosbeak was a subdued rambling war- ble, interrupted with whistling notes; that of the Crossbill bolder and more pronounced as a song. During the third week in April a male was daily heard singing about the same spot, and on the 22d, in following up his notes, I came upon the female busily at work upon her nest. Several times I watched it arrange a burden of build- least the males were not in full song before June 10, and even so that date they were not generally mated. My utmost efforts to discover the nest failed. Some old ones, which were hung in the usual manner near the extremity of birch or poplar limbs, may have originally belonged to this species, as several specimens of the birds were found in the grove, and no other Vireo seemed to be breeding near. The only one of these structures which I took pains to examine closely was somewhat smaller and deeper than the average nest of Vireo olivaceus, being rather more like that of Vireo noveboracensis. At the close of the breeding season, when the brakes are turning brown, and occasional maples along the lake shore begin to glow with the burning tints of autumn, the Philadelphia Vireos join those great congregations of mingled Warblers, Sparrows, Woodpeckers, Titmice, etc., which at this season go trooping through the Maine woods. The specimens taken at Upton, in 1874, were in flocks of this kind, and several of them were shot in low bushes, an apparent exception to the rule previously given. But mixed society among birds, as well as men, is a great leveller of individual traits, and it is by no means uncommon on these occasions to find such tree- Vireo philadelphicus. 98