What is a suborder of Medusæ which includes very large species without marginal tentacles, but having large mouth lobes closely united at the edges. See Illust. in Appendix called?

rhizostomata — A suborder of Medusæ which includes very large species without marginal tentacles, but having large mouth lobes closely united at the edges. See Illust. in Appendix. (Webster's 1913.)