FORWARD

"Crayfishes (Astacidea) of North and Middle America" is the ninth of a series of identification manuals for selected taxa of invertebrates occurring in freshwater systems.  These documents, prepared by the Oceanography and Limnology Program, Smithsonian Institution for the Environmental Protection Agency, will contribute toward improving the quality of the data upon which environmental decisions are based.

Additional manuals will include, but not necessarily be limited to, freshwater representatives of the following groups:  amphipod crustaceans (Cammaridae), branchiuran crustaceans (Argulus), isopod crustaceans (Asellidae), leeches (Hirudinea), polychaete worms ( Polychaeta), freshwater planarians (Turbellaria), aquatic dryopid beetles (Dryopoidea) and freshwater clams (Sphaeriacea).