資料來源 : Webster's Revised Unabridged Dictionary (1913)

Hydrotheca \Hy`dro*the"ca\, n.; pl. L. {Hydrothec[ae]}, E.
   {Hydrothecas}. [NL., fr. E. hydra + Gr. ? a box.] (Zo["o]l.)
   One of the calicles which, in some Hydroidea (Thecaphora),
   protect the hydrants. See Illust. of {Hydroidea}, and
   {Campanularian}.