Umbonium ishiianum Yokoyama, 1930
| 1930. | Umbonium ishiianum Yokoyama, 1930 Syntype Yokoyama, M. 1930a p. 402, text-fig. (left) |
| Condition: | Present |
| Taxonomy: | Mollusca: Gastropoda: Trochidae: |
| Geologic Time: | Cenozoic: |
| Yokoyama, M., 1930a: Neogene shells from Yamashiro. Journal of the Faculty of Science, Imperial University of Tokyo, Section 2, vol. 2, pt. 10, pp. 399–403. (Reference No. 0498) |
 |
| Ichikawa, T., 1983, no. 9, p. 381. |
