(n.) One of the calicles which, in some Hydroidea (Thecaphora), protect the hydrants. See Illust. of Hydroidea, and Campanularian.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). Hydrotheca. Retrieved September 22, 2026, from http://smartdefine.org/hydrotheca/definitions/2018148 |
| Chicago | Webster's. 2011. "Hydrotheca" http://smartdefine.org/hydrotheca/definitions/2018148 (accessed September 22, 2026). |
| Harvard | Webster's 2011, Hydrotheca, Smart Define, viewed 22 September, 2026, <http://smartdefine.org/hydrotheca/definitions/2018148>. |
| MLA | Webster's. "Hydrotheca" 27 May 2011. Web. 22 September 2026. <http://smartdefine.org/hydrotheca/definitions/2018148> |