Geological Survey of Illinois. A. H. Worthen, Director
Report volumes of the Illinois state geological survey, directed by A. H. Worthen with contributions from Henry Martyn Bannister, Edward Travers Cox and Henry Engelmann, issued from 1866 for legislators, mining interests and naturalists. The plates are lithographed fossil studies in fine stipple and line, grouping crinoid calyxes, blastoids, corals and shell fragments as numbered specimens floating on blank grounds, useful for pattern-like plate layouts and detailed tonal natural-history cutouts.
