The Typification of the Diatom Species Coscinodiscus Concinnus Wm. Smith and Coscinodiscus Granii Gough

Abstract

The original descriptions of these two species are discussed and the material mentioned in Smith's description is examined. Discrepancies between Smith's description of Coscinodiscus concinnus and the present interpretation of this species are pointed out. Ways of typifying the two species so as to preserve current usage and still fulfil the requirement of the International Code of Botanical Nomenclature are given. Lectotypes for the two species are designated. Diagnostic characters distinguishing the two species in the living state as well as the cleaned valves are given.