Mesosceptron Fucini, 1915 from the Sinemurian of Sicily. An aulacoceratid cephalopod and not an octocoral

The genus Mesosceptron Fucini, 1915 from the Sinemurian of Montagna del Casale, Sicily, was originally described as a pennatulacean octocoral. The nominal genus is based on eight new species; no type species was fixed in the original publication. Re-examination of the type specimens of these species shows that they are incompletely preserved coleoid rostra that according to current systematic practice may belong to more than one genus within the xiphoteuthidid Aulacoceratida. In order to clarify the systematic attribution of the nominal genus Mesosceptron, we designate herein as its type species, M. neumayeri, and designate a lectotype for the latter; we also designate lectotypes for M. exagonum and M. magnum. Consequently to this nomenclatural act, the nominal genus Mesosceptron becomes a subjective junior synonym of Atractites Gümbel, 1861. We also include herein comments upon nomenclatural aspects of the co-occurring ammonite fauna.