Abstract
The taxonomy of the genus Typhlocypris Vejdovský, 1882 is reviewed. New morphological information on Typhlocypris eremita (Vejdovský, 1882), the type species of the genus, is provided, and a new reference material is presented. The generic diagnosis is emended with details derived from the developmental trajectory of the valves, from the juvenile stage A-3 to the adult. Those criteria clearly differentiate Typhlocypris from the related genus Pseudocandona Kaufmann, 1900. As here redefined, Typhlocypris is a phylogentic lineage of the subfamily Candoninae containing extant species presently living in aquatic subterranean habitats and fossil species recovered from non-marine Late Palaeogene to Neogene and Quaternary deposits in Europe and western Asia. The type species of Typhlocypris is considered a metaspecies, taxonomically treated as T. eremita (sensu lato), which includes populations resembling the newly designated reference material. The homeomorphic triangular valve shape of the Candoninae is discussed. Careful examination of the valve morphology of Typhlocypris combined with the analysis of limb traits helps to distinguish representatives of this genus from unrelated phylogenetic groups presenting similar triangularly shaped valves. It is emphasised that for a useful description of Typhlocypris taxa both transmitted light and scanning electron microscopy are necessary.