The"ca (?), n.; pl. Thecae (#). [L., fr. Gr. a case to put anything in. See Tick a cover.]


A sheath; a case; as, the theca, or cell, of an anther; the theca, or spore case, of a fungus; the theca of the spinal cord.

2. Zool. (a)

The chitinous cup which protects the hydranths of certain hydroids.


The more or less cuplike calicle of a coral.


The wall forming a calicle of a coral.


© Webster 1913.