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

Pennsylvanian invertebrates of the Mazon Creek area, Illinois: the Essex fauna and medusae / Ralph Gordon Johnson -- and Eugene S. Richardson, Jr. -- The essex fauna and medusae. Johnson, Ralph Gordon, 1927-1976 Richardson, Eugene Stanley, 1916- text book [Chicago] : Field Museum Press , 1968. 1968 English Essex Illinois Jellyfishes, Fossil Paleontology Pennsylvanian QE1 .F4 vol. 12, no. 7 563/.7 Fieldiana. Geology ; v. 12, no. 7 Publication (Field Museum of Natural History) ; 1043 http://www.biodiversitylibrary.org/bibliography/3425 444253 68026377 DLC