Anchicodium Johnson: branched or phylloid?

Abstract

Membranous phylloid algae of the late Paleozoic have commonly been identified as Anchicodium Johnson, whereas the genus was originally described as being cylindrical and branched, much like modern Codium. The holotypes cannot be located, but examination of one lectotype specimen and neotypic thin sections from material from several of Johnson's original collection sites indicates that the original descriptions were valid.