THE SENEGAL SWALLOW. The SENEGAL SWALLOW (_Cecropis Senegalensis_) is about eight inches long and fifteen broad; the wing measures five and a half, and the tail about four inches. The plumage of the upper part of the body is of a glossy blueish black, with the exception of the rump and a ring round the neck, which are reddish brown; the under side is entirely of the latter hue, somewhat paler upon the throat and upper part of the breast. This very large species inhabits Central Africa in great numbers, and is met with from the western coast to the shores of the Red Sea. In its mode of life and habits it so closely resembles the Chimney Swallow that a description of its habits would be mere repetition; unlike that bird, however, it does not always dwell in the immediate vicinity of man, but frequently wanders forth and lives upon the vast and barren steppes. Another very similar species is found in Angola and at the Cape of Good Hope. THE THREAD-TAILED SWALLOW. The THREAD-TAILED SWALLOW (_Cecropis-Uromitus-filifera_) is a small and delicate bird, easily recognisable by the long threads in which the two outer feathers of the tail terminate. The upper part of the body is of a beautiful metallic blue, the top of the head rust-red, the region of the cheeks black, the under side white, and the tail spotted with white. The length of this species is five, and its breadth eleven inches. The thread-like appendages are not so long in the tail of the female as in that of her mate. This singular bird principally frequents India and Central Africa, and we have met with it living solitarily or in pairs during our travels in Nubia. As far as we were able to ascertain, its habits exactly correspond with our account of its European congener. The Indians call this species "Leischra," as the threads attached to the tail are supposed to resemble the grass known by that name. THE MARTIN.