Knox, Robert W. O'B.: Ichnogenus Corophioides.
A re-examination of syntypes and topotypes of the type species, Corophioides polyupsilon, shows that its structure is distinct from that of the other forms ascribed to the ichnogenus. An emended diagnosis of the ichnogenus is given, restricting it to forms which show a true U-within-U structure. Most of the species formerly included in Corophioides Smith 1893 can be referred to Diplocraterion Torell 1870, but in some cases a re-examination of the type material is necessary.