rimoportula

plural rimoportulae

1. A lip-shaped structure in some diatoms

   1 more example

   Many araphid diatoms have parallel striae and a distinct sternum; many araphid diatoms (and even some centric diatoms, particularly in the Biddulphiaceae and Eupodiscaceae) have apical pore fields; other small araphid pennates (such as Staurosira species) and centrics (Corethron and Leptocylindrus) lack rimoportula; and occluded pores are found in most diatoms, albeit in a variety of siliceous structures.

   2015 October 15, “New Insights into Plagiogrammaceae (Bacillariophyta) Based on Multigene Phylogenies and Morphological Characteristics with the Description of a New Genus and Three New Species”, in PLOS ONE, →DOI