|F. R. C. Reed 1917||Shell subcircular, subquadrate, or transversely elliptical, unequally biconvex ; hinge-line rather less than maximum width of shell; cardinal angles obtuse, rounded or subrectangular. Pedicle-valve convex, subcarinate in young, deepest near middle; beak large, elevated, rising high above hinge-line, acute, slightly incurved ; hinge-area large, high, triangular, slightly concave, nearly half the length of shell in height, lying nearly in plane of valve, with narrow triangular delthyrium. Brachial valve much shorter and less convex than pedicle-valve, transversely elliptical in shape, more or less bilobed by a sharp median depression which extends from beak to front margin, increasing in width and causing sinuation of edge of valves; beak small, obtuse, rising slightly above hinge-line, slightly incurved, with narrow hinge-area below, set at right angles to that of other valve.
Surface of valves covered by numerous small rounded somewhat unequal closely placed riblets curving back a little on each side and numbering about 60 on the margins, about one-third of which are primaries, the others (usually rather smaller) arising somewhat irregularly by intercalation at about one-third or one-half their length. Concentric growth-ridges usually few, lamellose, strong, submarginal.
|A. Williams 1962||Subcircular, unequally biconvex Laticrura with a long, curved, apsacline, ventral interarea over one-quarter as long as the slightly carinate pedicle valve, about one-third as deep as long; brachial valve over two-thirds as long as deep, gently and evenly convex on the lateral shoulders to a deep median sulcus; radial ornamentation fascicostellate with sectors I and II of the brachial valve occupying the sulcus and including internally branching secondaries and tertiaries, external branches first appearing in the wider sectors III and IV; costellae angular, 3 per millimetre antero-medianly; ventral muscle-scar elongate with a truncated anterior boundary, about three-fifths as wide as long and extending forward of the parallel-sided dental lamellae for almost two-fifths of the length of the pedicle valve; ridge-like cardinal process continuous with strong, high, median septum, brachiophore supporting plates obtusely convergent on the median septum.|