Ellipsaria lineolata shell description:

“Shell subtriangular, solid, subcompressed or scarcely inflated, with a sharply defined up-curved posterior ridge, behind which it is truncated; region of the beaks and a considerable area of the upper part of the shell compressed; beak sculpture consisting of a few irregular, slightly doubly-looped ridges; beaks curved forward over a small, wide lunule passing back under the hinge, where it is filled with epidermal matter; ligament small, brown; surface with irregular, often rude, sometimes almost sulcate, growth lines; epidermis rather smooth, but showing fine, wrinkled loops under a glass, tawny or yellowish-green, generally with faint, broken rays, which are made up of dots or lunate or arrow-head markings; they are sometimes composed of alternately lighter and darker dashes; hinge strong, the plate often flattened; left valve with two triangular, ragged pseudodcardinals, a faint anterior third one, and two slightly curved laterals; right valve with three pseudocardinals, the middle one the largest, and two laterals, the lower the smaller; beak cavities moderately deep; muscle scars impressed, the anterior ones ragged; nacre silvery-white.  The male and female shell differ widely, the former are much the larger and are considerably compressed; the female shell is somewhat humped, is more or less inflated, is considerably produced at the posterior base and gaps a little in front and behind ”(Simpson, 2014; Mather, 2007).