Hy`dro*the"ca (?), n.; pl. L. Hydrothecae (#), E. Hydrothecas (#). [NL., fr. E. hydra + Gr. a box.] Zool.
One of the calicles which, in some Hydroidea (Thecaphora), protect the hydrants. See Illust. of Hydroidea, and Campanularian.
© Webster 1913.