On the Classification of the Fossiliferous Slates of North Wales, Cumberland, Westmoreland and Lancashire (being a Supplement to a paper read to the Society, March 12, 1845)
- 1 February 1847
- journal article
- Published by Geological Society of London in Quarterly Journal of the Geological Society
- Vol. 3 (1-2), 133-164
- https://doi.org/10.1144/gsl.jgs.1847.003.01-02.19