(Caprimulgidae; Ϯ Lyre-tailed Nightjar U. lyra) Gr. ουρα oura tail; ψαλις psalis, ψαλιδος psalidos pair of scissors, shears; "Uropsalis gen. nov. Type Hydropsalis lyra Bp. Related to Hydropsalis Wagl. and Macropsalis Scl.; differing from the former in having the central pair of rectrices shorter than instead of much longer than the next three pairs; from the latter in the much smaller wing, the outer three primaries not specially enlarged, the tenth shorter than instead of longer than the ninth, three instead of only two primaries emarginate on the inner web; and in the broadly rounded instead of tapering and obtusely pointed tips of the first four pairs of rectrices; the latter much less strongly graduated, the fourth pair exceeding the third by less than one-half the length of the first pair instead of by more than the length of the first. In addition to the type species, Hydropsalis segmentata Cass. is also referable to this genus. ... A further difference is seen in the long outer tail-feathers. In Macropsalis and Hydropsalis the shafts of these feathers are stout and strong, tapering very gradually to the tip. In Uropsalis the shaft, while not conspicuously more slender at the base, is rapidly reduced, and throughout the greater part of its length is very slender, only about half as thick as in Macropsalis; in the last four inches, however, it widens out and becomes twice as wide as at the corresponding point in Macropsalis. ... In Macropsalis and Hydropsalis the rectrices are conspicuously marked with white on the inner web. This is not the case in either of the species of Uropsalis." (Miller 1915).