original description(ofPaludina nympha Eichwald, 1850 †)Eichwald, C. E. (1850). Палеонтологiя Россiи. Новый перiодъ - Palaeontology of Russia. New Period]. <em>tipografija Ya. Ionsona [E. Pratz or R. Golike] Sanct Petersburg.</em> 1-284., available online athttps://books.google.pt/books/about?id=eC5ApsoaZfYC page(s): 135-136; note: figured in Atlas (1859: pl. 10, figs 27a-c) [details]