Myzostomata \My`zo*stom"a*ta\, n. pl. [NL., fr. Gr. my`zein to suck + sto`ma, -atos, mouth.] (Zo["o]l.) An order of curious parasitic worms found on crinoids. The body is short and disklike, with four pairs of suckers and five pairs of hook-bearing parapodia on the under side.