« Solen pinna: Solen with a thin, pellucid, fragile, depressed, white shell, of a sub-oval shape, strongly wrinkled concentrically ; umbo small, placed very near the smaller end, from whence the connecting cartilage runs in a straight line on the longest side, and joins the valves nearly the whole width of the shell, like a Pinna ; the short end declines a little from the beak ; the margin opposite the hinge is semi-circular, and extremely thin and brittle ; the valves are dissimilar, the upper is a little convex, the lower slightly concave. Inside white, somewhat pearlaceous ; a blunt tooth in each valve running straight from the beak ; that in the concave valve is largest, and uneven on its furface ; these are not inserted, but stand by the side of each other when the valves are closed. » – G. Montagu: Testacea brittanica vol. II, London 1803, via BHL.