资料来源 : Webster's Revised Unabridged Dictionary (1913)

Theca \The"ca\, n.; pl. {Thec[ae]}. [L., fr. Gr. ? a case to put
   anything in. See {Tick} a cover.]
   1. 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. (Zo["o]l.)
      (a) The chitinous cup which protects the hydranths of
          certain hydroids.
      (b) The more or less cuplike calicle of a coral.
      (c) The wall forming a calicle of a coral.

资料来源 : WordNet®

theca
     n 1: a case or sheath especially a pollen sac or moss capsule
          [syn: {sac}]
     2: outer sheath of the pupa of certain insects
     [also: {thecae} (pl)]

thecae
     See {theca}