BILEVIPEN'NES (Lat. short-winged), in ornithology, according to the system of Cnvier, that tribe of the order grallaores (q.v.) in which the ostrich, cassowary, rhea or nandou, emu, and apteryx are comprised, and also the extinct dodo.—See these articles. The B. are characterized by a shortness of wing which incapacitates them for flight, but use their wings to aid them in running, which they do with great rapidity. Their sternum. (breast-bone) has no ridge or keel. They constitute the family struthionidat of many ornithologists, and by some are placed among gallinaceous (q.v.) birds, to which they are allied by the form of their bill and their choice of food. They are, however, very different from all other birds, and whether ranked among grallatores or gallinaceous birds, do not seem to form a natural part of the order. The gigantic dinoris (q.v.) and
other fossil birds of great interest exhibit the characters of the breripennes.
Gigantic birds, of which the footsteps appear imprinted on sandstones in the valley of the Connecticut and elsewhere, seem also to have belonged to this tribe. No remains or traces of such birds are, however, found nearly so ancient as many remains of quad rupeds. But to whatever geological period the commencement of their existence is to be referred, a peculiar interest is attached to them, because its close may be regarded,as probably near. There is no tribe of birds that more generally shuns man, or disappears before the increase of population and the progress of colonization. The cassowary- and the emu are rapidly becoming rare. The ostrich, the rhea, the apteryx, the notornis, etc., are only found in deserts or other deep solitudes.