am·phi·the·ci·um 
(ăm′fə-thēshē-əm, -sē-əm)
(ăm′fə-thēshē-əm, -sē-əm)n. pl. am·phi·the·ci·a (-shē-ə, -sē-ə)
The outer layer of cells of the spore-containing capsule of a moss.
[New Latin amphithēcium : AMPHI- + Greek thēkion, diminutive of thēkē, receptacle; see dhē- in the Appendix of Indo-European roots.]