Zoological lectures delivered at the Royal Institution. London, Kearsley, 1809, zoology, This illustration features a detailed depiction of the nautilus pompilius, commonly known as the pearly nautilus. The upper section presents a top view of the shell, showcasing its intricate spiral pattern and smooth, curved exterior. Below, a longitudinal section reveals the internal structure, highlighting the chambered design that characterizes this marine mollusk. The labels indicate the purpose of the section, providing insight into the biological and anatomical features of the nautilus, which is known for its unique shell and buoyancy.