Entolium japonicum Kurata & Kimura in Kimura, 1951
KIMURA, T. 1951. Some pectinids and a limid from the Jurassic Torinosu group in Japan. Journal of the Faculty of Science, University of Tokyo [Section II: Geology, Mineralogy, Geography, Seismology], 7 (6-10): 337-350, pI. 1 [p. 345, pl. 1, figs. 16, 17]
1951 Entolium japonicum Kurata & Kimura in Kimura, 1951
T. Kimura, 1951, plate 1.
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«Entolium japonicum KURATA and KIMURA, n. sp.
PI. I, Figs. 16, 17. Description:— Shell equivalve, a little convex, elongately ovate, higher than long, somewhat inequilateral; posterior margin more rounded than the anterior; antero-dorsal slightly concave below the ear; postero-dorsal straight; beak pointed, rather small; anterior ear thrice or less longer than the posterior; hinge line straight and horizontal; anterior ear nearly flat, well defined inside by an angularity, its anterior margin being a little oblique or nearly vertical; posterior margin oblique, forming an obtuse angle with the hinge margin at the postero-dorsal extremity.
Surface smooth. Internally the resilifer defined by a bifid ridge, the posterior branch of which is extending far into the posteroventral part. Comparison:— This species is characterized by its tall outline and ears very unequal for Entolium. In some specimens from Iwasa, however, the outline is more equilateral, ears quite equal in size and form, and with an aid of a magnifer fine crowded radial as well as concentric lines seen on the surface. The left valve of this species is sometimes very difficult to distinguish from that of Camptonectes torinosuensis, especially in the case that the specimens have heen secondarily deformed.
Occurrence:— Mimikire, Iwasa and Arinoki. NOBUO KURATA & TOSHIO KIMURA, 1951
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