canal tangentiel

OBS: (...) les nervures saillantes de la thèque renferment les canaux tangentiels serrés les uns contre les autres; (...)

OBS: [A tangential pore canal is a] subepithecal pore canal in (...) [some cystoids] which runs parallel to [the] surface of [the] thecal plates and connects 2 pore canals normal to [the] inner surface of different plates; each tangential pore canal extends through [the] stereotheca of 2 adjacent thecal plates.