original description
Yokoyama M. (1932). Tertiary Mollusca from the Coalfield of Uryu, Ishikari. <em>Journal of the Faculty of Science, Imperial University of Tokyo. Section II, Geology, Mineralogy, Geography, Seismology.</em> 3(6): 221-247., available online at http://umdb.um.u-tokyo.ac.jp/DKoseibu/pdf/Ref_0503_.pdf
page(s): 243, pl. 3, figs 1, 2 [details] Available for editors [request]
From editor or global species database
Type locality "Upper Tachibets Beds: The Sasakizawa; the Nasuzawa, a branch of the Urashimagawa. Lower Tachibets Beds: The Kikyozawa, a branch of Mappugawa" (Hokkaido, Japan) [details]