Descrição original: Verrill A.E. and Bush K.J. (1900). Additions to the marine Mollusca of the Bermudas. Transactions of the Connecticut Academy of Arts and Sciences 10: 513-544., available online at http://www.biodiversitylibrary.org/page/13457318 page(s): 526, pl. 64 fig. 8 [fig. 9 in error]