Myzostomata :: Myzostomata (n. pl.) 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..
Rhizostomata :: Rhizostomata (n. pl.) A suborder of Medusae which includes very large species without marginal tentacles, but having large mouth lobes closely united at the edges. See Illust. in Appendix..