Type examination of the freshwater centric diatom Aulacoseira pusilla (F. Meister) Tuji et Houki

Abstract

A slide in the Tempère & Peragallo exsiccata set (Tèmpere & Peragallo 1913), which is thought to be an isotype material for Melosira pusilla F. Meister, was examined. The form of frustules, density of striae and position and number of rimoportulae, agree with the specimen examined from Katata lagoon, Shiga Pref. supporting the results of Tuji &Houki (2004), who proposed the new combination, Aulacoseira pusilla (EMeister) Tuji et Houki. Aulacoseira subborealis (Nygaard) Denys, Muylaert & 'Crammer may also be a synonym of this taxon.