Whitfield, Robert Parr, 1828-1910.Newton, Henry, 1845-1877.Hovey, Edmund Otis, 1862-1924.2005-10-062005-10-061902http://hdl.handle.net/2246/747p. 67-72, [5] leaves of plates : ill. ; 24 cm.Includes bibliographical references.3745270 bytesapplication/pdfen-USQH1 .A4 vol.16, art.5, 1902Heteroceras simplicostatum.Ammonoidea -- Black Hills (S.D. and Wyo.)Ammonoidea -- South Dakota.Mollusks, Fossil -- Black Hills (S.D. and Wyo.)Mollusks, Fossil -- South Dakota.Paleontology -- Cretaceous -- Black Hills (S.D. and Wyo.)Paleontology -- Cretaceous -- South Dakota.Paleontology -- Black Hills (S.D. and Wyo.)Paleontology -- South Dakota.Observations on and emended description of Heteroceras simplicostatum Whitfield. Bulletin of the AMNH ; v. 16, article 5.Observations on Heteroceras simplicostatumtext