- alula, calypter - scale-like structure between the base of the wing and the halter of a two-winged fly
--1 is a kind of squama
--1 is a part of fly - bastard wing, alula, spurious wing - tuft of small stiff feathers on the first digit of a bird's wing
--2 is a kind of feather, plume, plumage
--2 is a part of wing