Umbonium giganteum naganumanum Otuka, 1930
| 1930. | Umbonium giganteum naganumanum Otuka, 1930 Paratype Otuka, Y. 1930 p. 25 |
| Condition: | Present |
| Taxonomy: | Mollusca: Gastropoda: Trochidae: |
| Geologic Time: | Cenozoic: |
| Otuka, Y., 1930: A new variety of fossil Umbonium. Journal of the Geological Society of Tokyo, vol. 37, no. 436, pp. 25–26. (Reference No. 0381) |
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| Ichikawa, T., 1983, no. 9, p. 75. |
