Siphonacmea oblongata (Yokoyama)
| 1958. | Siphonacmea oblongata (Yokoyama) Syntype Makiyama, J. 1958 pl. 46, fig. 14 |
| 1926. | Acmaea oblongata Yokoyama, 1926 Syntype Yokoyama, M. 1926f p. 288, pl. 34, fig. 14 |
| Condition: | Present |
| Taxonomy: | Mollusca: Gastropoda: Siphonariidae: |
| Geologic Time: | Cenozoic: Pliocene: |
| Horizon: | Sawane formation: |
| Makiyama, J., 1958: Matajiro Yokoyama's Tertiary fossils from various localities in Japan. Part 2. Palaeontological Society of Japan, Special Papers, no. 4, pp. 1–6, pls. 25–57. (Reference No. 0368) |
| Yokoyama, M., 1926f: Fossil shells from Sado. Journal of the Faculty of Science, Imperial University of Tokyo, Section 2, vol. 1, pt. 8, pp. 249–312, pls. 32–37. (Reference No. 0483) |
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| Ichikawa, T., 1983, no. 9, p. 53. |
| Ichikawa, T., 1983, no. 9, p. 327. |
