These sand dollars virtually paved the surf zone offshore just below the low tide level. This large individual is 12 cm (4 in) in diameter. Innumerable smaller individuals (2 to 4 cm diam.) were abundant under foot in that zone. Numbers of them washed ashore after a strong rainstorm. This is likely to be Mellita tenuis which was originally described from off of Sanibel Island, but I don't know if M. quinquiesperforata also occurs here. M. tenuis was originally described as a subspecies of the latter.
20 June 2016, 12:00 -14:00 Wildwood, New Jersey 38.97, -74.81 0.3 meters ID changed to Mellita tenuis (was M. quinquiesperforata) based on collection locality (see Coppard et al. 2013)