Shell size to 45 mm; shell equivalve, valves convex, hinge with wing-like projections of unequal size. Surface sculpture of 18 to 20 ribs, each with three rows of sharp scales. Color reddish-brown, orange, rarely lemon-yellow. In February 2010, individuals of this species were found on the east end of Sanibel Island covered (both valves) with the sponge Myxilla incrustans (Esper, 1905) (see photos.) The clean shells illustrated are from the collection of Ken and Alice Piech, collected on Sanibel on January 28, 2010.