‖n.; pl. Hydromedusæ [ NL. See Hydra, and Medusa. ] (Zool.) Any medusa or jellyfish which is produced by budding from a hydroid. They are called also Craspedota, and naked-eyed medusæ. [ 1913 Webster ]

☞ Such medusæ are the reproductive zooids or gonophores, either male or female, of the hydroid from which they arise, whether they become free or remain attached to the hydroid colony. They in turn produce the eggs from which the hydroids are developed. The name is also applied to other similar medusæ which are not known to bud from a hydroid colony, and even to some which are known to develop directly from the eggs, but which in structure agree essentially with those produced from hydroids. See Hydroidea, and Gymnoblastea. [ 1913 Webster ]

‖n. [ L., fr. Gr. &unr_;. ] 1. (Class. Myth.) The Gorgon; or one of the Gorgons whose hair was changed into serpents, after which all who looked upon her were turned into stone. [ 1913 Webster ]

2. [ pl. Medusae ] (Zool.) Any free swimming acaleph; a jellyfish. [ 1913 Webster ]

☞ The larger medusae belong to the Discophora, and are sometimes called covered-eyed medusae; others, known as naked-eyed medusae, belong to the Hydroidea, and are usually developed by budding from hydroids. See Discophora, Hydroidea, and Hydromedusa. [ 1913 Webster ]

Medusa bud (Zool.), one of the buds of a hydroid, destined to develop into a gonophore or medusa. See Athecata, and Gonotheca. --
Medusa's head. (a) (Zool.) An astrophyton. (b) (Astron.) A cluster of stars in the constellation Perseus. It contains the bright star Algol. [ 1913 Webster ]

‖n. pl. [ NL. See Polyp, and Medusa. ] (Zool.) Same as Hydrozoa. [ 1913 Webster ]

‖n. pl. [ NL., fr. Gr. sky`fos cup + NL. medusa. ] (Zool.) Same as Acraspeda, or Discophora. [ 1913 Webster ]

‖n. pl. [ NL., fr.Gr. &unr_; rough + medusa. ] (Zool.) A division of acalephs in which the development is direct from the eggs, without a hydroid stage. Some of the species are parasitic on other medusae. [ 1913 Webster ]