Eocylichna musashiensis (Tokunaga, 1906)

Description

A small cylichnid snail with a thick, polished white shell about 12 mm long. The shell is elongate-ovate and broadens toward the base; the apical region is angulated and the apex is perforated. Spiral grooves are fine but become distinct around the base. The columella bears a strong fold above.

Distribution

Habe (1961) recorded the species from Honshu to Kyushu in 20–155 m depth on fine sand bottoms. Okutani (ed.) 2000 (Marine Mollusks in Japan) extended the recorded range from Boso Peninsula on the Pacific coast and Wakasa Bay on the Japan Sea coast southward to the South China Sea, on fine sand bottoms in 20–200 m depth.

Etymology

The specific epithet musashiensis is a Latin adjective referring to Musashi, the historical province encompassing the Tokyo region; the suffix -ensis denotes geographic origin. The species was originally described from fossil specimens collected from a sedimentary formation near Tokyo.

Remarks

The original description (Tokunaga, 1906) was based on fossil material from near Tokyo, where the species was named Cylichna musashiensis. It has subsequently been recorded from extant material in Japanese waters as well. Habe (1961) distinguished a similar but more cylindrical species, Eocylichna protracta (Gould), from the west coast of Kyushu and the Chinese coast.

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References

• Cylichna musashiensis n. sp. [fossil from Tokyo], Tokunaga S. (1906). Fossils from the environs of Tôkyô. Journal of the College of Science, Imperial University of Tokyo. 21(2): 1-96, 5 pls.
• セキヒツクダタマガイ Eocylichna musashiensis (TOKUNAGA), 波部忠重. (1961). 続原色日本貝類図鑑. 保育社, 大阪. xii + 183 + 42 pp., 66 pls. [Habe T. (1961). Coloured illustrations of the shells of Japan (II). Hoikusha, Osaka.]
• セキヒツクダタマガイ Eocylichna musashiensis (Tokunaga, 1906), 奥谷喬司. (2000). 日本近海産貝類図鑑. 東海大学出版会.