Pennsylvanian invertebrates of the Mazon Creek area, Illinois: the Essex fauna and medusae / Ralph Gordon Johnson -- and Eugene S. Richardson, Jr. --

v.12:no.7(1968)

New fossil polychaete from Essex, Illinois / Ida Thompson -- and Ralph G. Johnson --.

v.33:no.25(1977)

Bandringa rayi: a new Ctenacanthoid shark from the Pennsylvania Essex fauna of Illinois / Rainer Zangerl --

v.12:no.10(1969)

A crinoid from the Pennsylvanian Essex fauna of Illinois / N. Gary Lane --

v.12:no.9(1969)