Geological Survey of Illinois. A. H. Worthen, Director
A state-funded geological report issued from 1866 under director A. H. Worthen, with contributions by Bannister, Cox, Engelmann and others, prepared for Illinois officials, surveyors and working geologists. The plates are lithographed fossil studies drawn in flat grey-green tints: coal-measure ferns, seed-fern fronds and tree-bark fragments arranged as loose groups of stone slabs, useful for silhouettes, leaf repeats and specimen-style page layouts.
