Proceedings of the Zoological Society of London, London, Zoological Society of London, The illustration features a detailed depiction of a Geodia Barrettii, a species of sponge from the family Geodiidae. The central focus is a rounded, textured body of the sponge, showcasing its unique surface characteristics and natural forms. Surrounding the sponge are various scientific representations, including a star-shaped figure and elongated spicules, which highlight the intricate biological structures associated with marine sponges. The label indicating the species name emphasizes the scientific context of the illustration, suggesting a study of marine life and its diverse forms.