Byssonichia radiata

Silurian Period clam fossil found in Waynesville, Ohio stored in Muséum National D'Historie Naturelle Jardin Des Plantes Paléontologie et Anatomie Comparée, Paris, France.  The clam is called Byssonichia radiata.
UPDATE: Solius Symbiosus of Swimming the Ordovician Seas blog left a comment that this pelecypod should be called Byssonychia radiata.  After looking it up I find that is has a new name Ambonychia radiata Hall, 1847 see this for more. Also it appears to be an Ordovician Period fossil and not a Silurian one. Thanks for the clarification.

Past references I have made to the Ambonychia:

http://louisvillefossils.blogspot.com/2009/03/ordovician-pelecypod-ambonychia.html

http://louisvillefossils.blogspot.com/2010/01/kope-formation-fossils.html

http://louisvillefossils.blogspot.com/2008/07/ordovician-pelecypod.html

http://louisvillefossils.blogspot.com/2010/05/fossils-of-bullitt-county.html