The Quarterly Journal of the Geological Society of London, v. 36 (1880). London, geology, periodicals., The illustration features a collection of prehistoric fossilized teeth and spines, specifically labeled as varieties of the species Pleuroacanthus. Each specimen is numbered for identification, showcasing distinct shapes and textures. The teeth exhibit varying sizes and serrations, suggesting adaptations for different feeding strategies or environmental conditions. The craftsmanship in the representation highlights the intricate details of the fossils, allowing for a closer examination of this ancient marine organism's anatomy.