epitheca

/ ˌɛpɪˈθiːkə /

noun

1. the outer and older layer of the cell wall of a diatom Compare hypotheca

Word History and Origins

Origin of epitheca¹

C19: from _epi- + _theca

Example Sentences

Septa radial; dissepiments present; an epitheca surrounds the base of massive or maeandroid forms, but only surrounds individual corallites in simple or branching forms.

From Project Gutenberg