original description
Yokoyama M. (1926). Fossil shells from Sado. <em>Journal of the Faculty of Science, Imperial University of Tokyo. Section II, Geology, Mineralogy, Geography, Seismology.</em> 1(8): 249–312, pls. 32–37., available online at http://umdb.um.u-tokyo.ac.jp/DKoseibu/pdf/Ref_0483_.pdf
page(s): pp. 276-277; plate 33, fig. 10 [details] Available for editors [request]
additional source
Makiyama, J. (1958). Matajiro Yokoyama's Tertiary fossils from various localities in Japan. Part II. <em>Palaeontological Society of Japan Special Papers.</em> 4: 1-6, pls. 25-57.
page(s): 5; plate 45, fig. 10 [details]
additional source
Ichikawa, T. 1983. Catalogue of Type and Illustrated Specimens in the Department of Historical Geology and Palaeontology of the University Museum, University of Tokyo. Part 2. Cenozoic Fossils and Recent Specimens. University Museum, University of Tokyo Material Reports No. 9. iv + 536 pp.
page(s): 52 [details]
From editor or global species database
Holotype Ichikawa (1983) lists the type material status and collection number: CM23142, Holotype. [details]