1Find a geology map of your area (they are all over the web)
2get a book on fossils of Echinoderms, Echinoids, or Crinoids (Im sure its one of these groups)
3Compare the picture in the book with yours (Id suggest a book like the "Treatise on Invertebrate Paleontology" or "Invertebrate Fossils" by Moore Lalicker and Fisher.(4th Ed I believe).
The Treatise... is on the web but is a reference mostly organized for pros. Its easily used by following the above groups and just compare the pictures. Dont bother with the bullshit, thats for the conehead researchers.