area of thickened silica extending from the central area of some pennate diatoms. A transverse fascia is formed by secondary deposition of silica into depressions on the valve. Examples of genera having a transverse fascia include Luticola and Staurophora. Plural form is facsiae.
See also stauros for a similar structure.
Cox, E.J. (2012). Ontogeny, homology, and terminology - wall morphogenesis as an aid to character recognition and character state definition for pennate diatom systematics. Journal of Phycology 48: 1–31. 10.1111/j.1529-8817.2011.01081.x
Image Credit: Loren Bahls
The fascia of Staurophora is the thickened, unornamented area near the central nodule. SEM images such as this one only show the surface features of the silica, so it is difficult to discern that the unornamented area is greater in thickness.
Image Credit: Pat Kociolek
Caloneis silicula has a fascia that often includes lunate markings.