NAUTILUS

The pearly nautilus is the only existing form belonging to the group Tetrabranchiata. Nautilus possesses four gills, and a beautiful, large, spirally coiled shell, pretty ornamented externally with wavy colour markings and with an exquisite pearly lustre within. The shell is divided into numerous chambers by means of a series of septa or walls, which are pierced by a hole in the centre through which a process passes in the living state of the animal. Specimens of an entire shell of nautilus pompilus and a section of the shell to show the chambers and the septa are exhibited.