A fascia is an area of thickened silica extending from the central area of pennate diatoms. A transverse fascia is formed by secondary deposition of silica into former depressions (Cox 2012). Also see definition for ‘stauros’. A number of genera possess a transverse fascia, including Luticola and Staurophora.
Series, or bundles, of rows of areolae oriented radially in some centric diatoms are termed fascicles.
Internal struts that provide structural support to the canal that contains the raphe. The fibulae extend transapically from the raphe canal to the valve face and are found in a number of genera including Denticula, Nitzschia and Surirella.
Footpole is a term used to describe the narrower end, or basal end, of the valve in genera (Didymosphenia, Gomphoneis, Gomphonema) that are club-shaped.
A small opening, perforation, or orifice; a fenestra.
Siliceous portion of diatom cell, a consisting of two valves, an epivalve and hypovalve and their associated cingulum elements
A tubular process of some centric diatoms, usually associated with the secretion of §-chitin to maintain buoyancy in the plankton. The fultoportula consists of a central tubular process surrounded by two or more satellite pores. Externally, the fultoportula appears as either a tube or a simple pore in the valve wall. The plural form is ‘fultoportulae’.
Broadest at the middle and tapering at both apices; spindle shaped.