WITH the exception of the Catalogue of Fossil Cephalopoda by Foord in the British Museum (Natural History) and the same author's monograph Carboniferous Cephalopoda of Ireland, the bibliography of this family as represented in Carboniferous time is scattered through many volumes and publications. Not one of the publications makes any attempt to define the precise horizon in the Carboniferous Series at which any one of the species occurs, or indicates its persistence in geological time.