Se*mae`o*stom"a*ta (?), n. pl. [NL., fr. Gr. a military standard + , , mouth.] Zool.
A division of Discophora having large free mouth lobes. It includes Aurelia, and Pelagia. Called also Semeostoma. See Illustr. under Discophora, and Medusa.
© Webster 1913.