1. Lower and Middle Devonian spores of north and central Vestspitsbergen;Allen;Palaeontology,1965
2. On the radial pitting in Callixylon;Arnold;American Journal of Botany,1929
3. The genus Callixylon from the Upper Devonian of central and western New York;Arnold;Papers of the Michigan Academy of Science, Arts and Letters,1930
4. Callixylon whiteanum sp. nov., from the Woodford chert of Oklahoma;Arnold;Botanical Gazette,1934
5. Upper Devonian (Frasnian) spores from the Carnarvon Basin, Western Australia;Balme;The Palaeobotanist,1962