The SHARP-BEARDED MASKED HUMMING BIRD (_Microrhamphus oxypogon_).--"I met with this fine species," says M. Linden, "for the first time in August, 1842, while ascending the Sierra Nevada de Merida, the crests of which are the most elevated of the eastern branch of the Columbian Cordilleras. It inhabits the region immediately beneath the line of perpetual congelation, at an elevation of from 12,000 to 13,000 feet above the level of the sea; it appears to be confined to the region between the 8th and 7th degree of north latitude. It occasionally perches on the scattered shrubs of this icy region, but most frequently on the projecting ledges of the rocks near to the snow. Its flight is swift, but very short. When it leaves the spot upon which it has been perched, it launches itself obliquely downwards, uttering, at the same time, a plaintive whistling sound, which is also occasionally uttered when perched; as far as I can recollect, I never heard it produce the humming sound made by several other members of the group, nor does it partake of their joyous spirit and perpetual activity. Its food appears to consist of minute insects, all the specimens we procured having their stomachs filled with small flies." "This bird," says Gould, "is never met with at a less elevation than 9,000 feet. It might be thought that such bleak and inclement situations were ill-adapted for so delicate a structure as that of the Humming Bird; but there and there only does it dwell, while the equally lofty paramas of Bogota are the native locality of the nearly-allied species, _Oxypogon Guerini_. The minute insects which frequent the Alpine flowers of these districts afford abundance of food to these birds, and their bills are beautifully constructed for searching amongst the flowers in which these are found." THE COLUMBIAN THORNBILL. The COLUMBIAN THORNBILL (_Ramphomicron heteropogon_) has only the feathers on the neck prolonged; the beak is sharp and pointed; the wings narrow, and of medium length; the broad tail is deeply forked. The entire mantle is of copper-green, the brow deep, rich green; and the long feathers on the throat of a somewhat metallic green in the centre, and orange-red at the roots and edges; the lower belly is greyish white, quills purplish brown, and tail greenish brown.