Thysanura

this-a-nū′ra, n. an order of wingle insects of small size, undergoing no metamorphosis, the abdomen usually bearing peculiar structures which seem to be abortive limbs, the spring-tails or bristle-tails.— adjs. Thysanū′rian ; Thysanū′riform . [Gr. thysanos , a fringe, our a , a tail.]