Professor king instituted the genus Schizodus for the reception of certain species of bivalves occurring in the Permian and Carboniferous systems, which had previously been quoted under the generic title of Axinus. In Dr. Woodward's Manual of Mollusca, 2nd edit. p. 431, Axinus is retained for these shells; and Schizodus is reduced to a synonym, because the name applied by Professor King had previously been employed by Mr. Waterhouse.