epitheca

Ancient Greek ἐπί (epí, “upon”) + θήκη (thḗkē, “case, box, receptacle”)

epitheca (plural epithecae)

1. (microbiology, planktology) The upper half of the theca of a thecate protist such as a diatom or dinoflagellate.
   • 1957, Sidney Frederic Harmer, The Polyzoa of the Siboga Expedition, page 1106:

     Cellariiform, the orifices nearly confined to the convex frontal and lateral surfaces; the basal surface with a strong median calcareous keel, almost concealed by a flat membranous epitheca, which covers the whole zoarium […]

• hypotheca

• epithecal

• Frustule

• petechia