First issued in release COL21.4.
Last used in release COL23.2
Published in
Williamson, W. C. (1880). On the Organization of the Fossil Plants of the Coal-Measures. Part X. Including an Examination of the Supposed Radiolarians of the Carboniferous Rocks. Philosophical Transactions of the Royal Society of London, 171(0): 493–539. https://doi.org/10.1098/rstl.1880.0014