Central tube

Central nodule

 

Cingulum

An internal tubular expression of the fultoportula


Citations

Houk, V., Klee, R. and Tanaka, H. (2014). Atlas of freshwater centric diatoms with a brief key and descriptions Part IV. Stephanodiscaceae B: Stephanodicsus, Cyclostephanos, Pliocaenicus, Hemistephanos, Stephanocostis, Mesodictyon & Spicaticribra. In: Poulícková, A. (ed.): Fottea 14 Supplement, 529 pp.