New and little-known ammonites from the Upper Cretaceous (Cenomanian and Turonian) of the western interior of the United States

An example of each of the genera Anisoceras, Desmoceras, Tragodesmoceras, Oalycoceras, Nigericeras, and the new genus Para.compsoceras is described from the western interior region.Anisoceras plicatile (.J. Sowerby) and Oalycoceras naviculare (Mantell), species described originally from England, are recorded from the Greenhorn Limestone of southeastern GoloTado.Desmoceras scotti (Moreman), known previously only from the Eagle Ford Formation of Texas, was discovered recently in the Greenhorn Limestone of southeastern Colorado and in the Mancos Shale of northeastern Arizona.JJloremanoceras, a new subgenus, is proposed for this species.The West African lower Turonian genus Nigericera8 is recorded for the first time in the western interior; it is represented by N. scotti, n. sp.The ne•w genus Paracompsoceras (type species, P. landisi, n. sp.) is proposed for a late Cenomanian ammonite from New Mexico that has juvenile whorls resembling those of Acanthoceras and adult whorls resembling those of Acompsoceras.Tragodesrnocera8 ca1"lilense, n. sp., is described from the lower part of the Carlile Shale of the Black Hills area.