Descrição original: Conrad, T. A. (1837). Description of new marine shells, from Upper California. Collected by Thomas Nuttall, Esq. Journal of the Academy of Natural Sciences, Philadelphia. 7: 227-268, pls 17-20., available online at http://biodiversitylibrary.org/page/24676893page(s): 239-240, pl. 20 fig. 4