This is a beautify shell that can only be appreciated when seen just collected live from the water. It is among that group of bivalve shells that is capable of displaying an iridescent rainbow of colors. However, the natural brilliance of its coloration fades quickly. I attempted to capture the iridescence in these photos, and was able to come close to capturing the rich coloration. In her book Bivalve Seashells of Florida: An identification guide to the common species of Florida and the Southeast, Trish Hartmann comments that A. papyrium has "faint, tan, zigzag lines which are just barely visible." While some varieties of this species are rather dull in coloration, these photos illustrate that A. papyrium can be a striking shell. 

I have found A. papyrium in lagoonal waters on both sides of Florida, but have not found it in the Florida Keys. It is always found among grasses on bottoms that have a muddy component. The bottom in the Florida Keys is mostly composed of coral silt and sand, which may be why I've yet to find A. papyrium there. However, Mikkelsen & Bieler (2008) report it in the Keys as rare. 

This specimen was photographed at Jupiter Sound, Palm Beach County. Florida. 18 mm

                                                                            Photos by Marlo F. Krisberg