MolluscaBase name details
original description
Pilsbry, H. A. (1926). A fresh-water snail, <i>Physa zionis</i>, living under unusual conditions. <em>Proceedings of the Academy of Natural Sciences of Philadelphia.</em> 77: 325-328., available online at http://www.jstor.org/stable/4063979
page(s): 326, pl. 11, fig. 5 [details]