Galeommella utinomii gen. et sp. nov. (Galeommatidae)
Shell small, white, ellipsoidal, moderately convex ; umbo small, elevated above the dorsal line; surface marked by about 20 distinct a little radial cords in the broad middle part; in the anterior and posterior dorsal areas radial cords are quite weakened but densely set; the interior white and polished ; the margin crenulated by the terminations of the radial cords, especially at the antero- and posterodorsal margins the crenulation is minutely but sharply marked as in the species of the genus Galeomma ; ventral margin does not gape.
This species lives on the sandy bottom in shallow water, the shell of which is wholly covered with the mantle which has mamy reddish papillae.
Height 3.8 mm., length 5.8 mm. and breadth 1.2 mm. (right valve)
(type specimen figured) Height 3. 7 mm., length 5. 6 mm. and breadth 1. 2 mm. (right valve
paratype specimen)
Type locality: Tomioka, Reihokucho, Amakusa, Kyushu. Remarks: The new genus Galeommella differs from the genus Galeomma in having the thin shell with the distinct radial ribs and without the gaping at the ventral margin. Galeomma japonica A. Adams from Minosima (Mishima) in Japan Sea seems to be closely related to this new species, but the description of that species is too brief to be satisfactorily identified with this new species.