| Shell is pyriform or flask shaped, composed of euglyphid idiosomes embedded in an unstructured organic cement, or often covered with a thick layer of organic cement giving the shell a smooth appearance. In the broad view two large (2–5µm) and conspicuous pores in depressions connected by internal tubes situated at the base of the neck Shell is lacking pores in depressions connected by internal tube. Shell composed of siliceous plates or diatom frustules, sometimes covered with a thick organic layer giving the impression that the shell is entirely self-secreted organic, hyalinous and non-structured, or composed of agglutinated particles (unique case of Padaungiella nebeloides) |
