What's the difference between pyxidium and pyxis?

Pyxidium

Definition:

• (n.) A pod which divides circularly into an upper and lower half, of which the former acts as a kind of lid, as in the pimpernel and purslane.
• (n.) The theca of mosses.

Example Sentences:

Pyxis

Definition:

• (n.) A box; a pyx.
• (n.) A pyxidium.
• (n.) The acetabulum. See Acetabulum, 2.

Example Sentences:

• (1) The Pyxis Medstation system was implemented on two nursing units at a 1000-bed tertiary-care referral hospital.