æginidæ

from The Century Dictionary.

• A family of Trachymedusæ, typified by the genus Ægina, containing craspedote acalephs with a hard discoidal umbrella, pouchlike enlargements of the digestive cavity, and the circular vessel usually reduced to a row of cells: related to Geryoniidæ and Trachynemidæ.
• A family of Narcomedusæ, having a circular canal communicating with the stomach by double peronial canals, with internemal gastral pouches, and without otoporpæ. It contains the genera Ægina, Ægineta, Æginopsis, and others.