Fig. 1 in New annulate Carboniferous orthoconic and cyrtoconic cephalopods of the family Brachycycloceratidae Furnish, Glenister & Hartman, 1962

Fig. 1. The Late Viséan ammonoid stratigraphy (with substages of the British regional subdivision) in the Rhenish Mountains and the occurrence of species of the Brachycycloceratidae. H. = Holkerian; SER. = Serpukhovian; PEN. = Pendleian.