Surirella gradifera Hust. Surirella gradifera Hust., Huber-Pestalozzi, Phytoplankt. Süsswass. vol. 2 (2), 501, fig. 605. 1942is basionym for Iconella gradifera (Hust.) Cocquyt & R.Jahn in PhytoKeys 82: 89. 2017