"A Patelliform gastropod, Palaelophacmaea criola : a new genus and species from the lower Ordovician of central Pennsylvania."; "Donaldson, Alan C., 1929-"; "Geology, Stratigraphic--Ordovician.", "Geology, Stratigraphic--Pennsylvania."; "Donaldson, Alan C., 1929-"; "1962"; "Journal article reprint from: Proceedings of West Virginia Academy of Science, v.34 (1962)."; ""; "P18134"; "pec"; "Geology, Stratigraphic--Ordovician.", "Geology, Stratigraphic--Pennsylvania."; "14256"; .