p.1

Gryphaea mutabilis, Morton-Jour. Acad. Nat. Sc. vol. 6 pl. 4 fig. 3- Synopsis page 53, pl. 4 fig. 3

Suborbicular, smooth, broadly expanded each side of the hinge; upper valve slightly concave, concentrically striated, outer edge reflected obliquely upwards to the disc of its fellow, with a few lines radiating from the apex to the periphery; lower valve convex, transversely undulated, lobed by a longitudinal groove; cicatrix, subovate; umbo prominent; beak slightly incurved.

L 4.0 - B 4.5-