Shell of somewhat the general character of Corbula fragilis and C. scaphoides (from the Pacific coast of Mexico and the Philippines respectively), but differing in proportions from either. Color whitish with a brownish tinge at the margins, internally with a glassy polish, externally dull; shell inequilateral, one third being anterior to the umbones ; inequivalve, but not markedly so ; anterior margin evenly rounded ; ventral margin waved, slightly concave nearly opposite the beaks, then swelling, then again a little concave just before the posterior angulation ; posterior haemal margin straight, declining from the beaks to the first angulation, then obliquely straightly truncated toward the extremely acute posterior angle formed by the principal carina ; beaks moderately prominent, flattened on top, not involute; from them a strong rounded carina extends to the tips of the shell, growing sharper posteriorly; another fine but very sharp carina extends from above the ligament close to and nearly parallel with the hinge margin, which its posterior termination slightly angulates ; these form an extremely narrow concave lunule, while the space between these carina; and the more prominent second pair of carina? is distinctly excavated, and is crossed by the wave-like sculpture only near the posterior portion, the rest being nearly smooth, except for the extremely fine radiating lines, which are better defined here than elsewhere on the shell; these last cover the entire shell, and have not the appearance of grooves, they are visible only with a glass, and are best defined on the posterior face, as above mentioned, and in the furrows; other sculpture of about ten regular concentric waves, with wider and very uniform interspaces, which, however, in adults (as in all Corbulae) begin to be crowded at the extreme margin ; there is no anterior lunule or carina, the tooth is very slender and small, and the whole shell is very thin. Lon. 13.5 ; alt. at beaks, 7.5; max. diameter, 5.0 mm. This species is remarkable for its acuminated posterior end, and as very thin, nearly equivalve, ventrally slightly concave, and for its slender and elongated form.