Abstract
A new genus (Gijfenia) is described from a re-investigation of Nitzschia cocconeiformis Grun. found in material deposited in the Natural History Museum (London) by Giffen. It is an extremely robust diatom with chambering of the valve in the “pinnularioid manner”. A light and scanning electron microscope study of its morphology is provided together with comment on its classification. Gijfenia is compared with some other species in the literature. In the same material Nitzschia (Tryblionella) lanceola Grun. was found and in SEM the “spines” reported in the literature were discovered to be spathulate.