Key to Ephemeropteran Families COUPLET 47. Hind wing sometimes absent or reduced in size (fig 20), wings hyaline, margins in imago not fringed with hairs, outer fork (OF) of Rs in fore wing normal (fig 4) or R5 detached basally from R4(fig 20)
8. Hind wing absent, wings milky, fringed with minute hairs in both imago and subimago, outer fork (OF) of Rs very deep (fig 9)
