Osteographie ou Description iconographique comparee du squelette et du système dentaire des Mammifères recents et fossiles, Paris, J.B. Baillière et fils, 1839-1864, Henri Marie Ducrotay, The illustration features a comparative study of various animal skulls, showcasing their side profiles and frontal views. The top section displays the skulls of different marine mammals, emphasizing the anatomical differences among species. The middle segment includes more detailed depictions of skull structures, highlighting features such as the nasal openings and jawlines. The lower part focuses on additional skulls, providing insights into evolutionary adaptations across these creatures. Labels accompany each skull, indicating their species for educational reference. This artwork serves as a valuable resource for understanding the morphology and classification of these animals.