Williams, D.M. (2001) Comments on the structure of "post-auxospore" valves of Fragilariforma virescensIn: Jahn, R., Kociolek, J.P., Witkowski, A and Compère, P. (eds), Lange-Bertalot-Festschrift: Studies on Diatoms. Dedicated to Prof. Dr. Dr. h.c. Horst Lange-Bertalot on the occasion of his 65th Birthday. A.R.G. Gantner Verlag. K.G. pp. 103-117.