original description(ofHelix undina L. Pfeiffer, 1856)Pfeiffer, L. (1856). Descriptions of twenty-five new species of land-shells, from the collection of H. Cuming, Esq. <em>Proceedings of the zoological Society of London.</em> 24 (302): 32; 24 (303): 33-36. London [16 June]., available online athttps://www.biodiversitylibrary.org/page/12860555 page(s): 34 [details]