Fauna of the Accraian Series (Devonian of Ghana) including a Revision of the Gastropod Plectonotus

The fauna of the Accraian Series of Ghana was studied and the following identifications were made: a species of terebratuloid, Discinisca sp., Lingula sp., Pleurodapis luriea n. sp., Leiopteria sp., Leptodesma? sp., Ptychodesma sp., Nuculana sp., Sphenotus sp., Nuculites sp., Plectonotus fraternus (Reed), Holopea sp., Hyolithes cf. aclis Hall, Hyolithes sp., Tentaculites sp., Prismodictya sp., coarse meshed Dictyosponge, algal growths, plant fragments, fragments of crustaceans, an Arthrophycus-like track or trail, and two unidentified ostracods. In addition a new homalonotid was identified, description of which is reserved for a separate paper. This faunal assemblage could be either Lower or Middle Devonian in age. The Accraian Series can not be satisfactorily correlated with any Lower or Middle Devonian strata studied to date. The results of this study are not adequate to decide if the faunal facies of the Accraian Series is more closely related to the faunal facies of beds of comparable age in North Africa, South Africa, or South America. Excellent specimens of Plectonotus show that the genus develops a true slit and a selenizone and not simply a sinus and pseudo-selenizone. This revision necessitates transfer of the genus from the Sinuitidae to the Bellerophontidae. Plectonotus is known to range from the Llandovery to at least early Emsian or possibly early Eifelian. The stratigraphic range of Prismodictya is extended down into the Lower or Middle Devonian.