“The cephalopodous molluscs,” says Figuier, a writer who in descriptive powers is an artistic scientist and a scientific artist, “are indeed highly organised for molluscs, for they possess in a high degree the sense of sight, hearing, and touch. They appear with the earlier animals which present themselves on the earth, and they are numerous even now, although they are far from playing the important part that was assigned to them in the early ages of organic life upon our planet. The Ammonites and Belemnites existed by thousands among the beings which peopled the seas during the secondary epoch in the history of the globe.” The Cephalopods were divided by Professor Owen into two great orders, _Tetrabranchiata_, or animals having four gills, and the _Dibranchiata_, having two gills. The first order has at this epoch but one genus, that of _Nautilus_. This group of animals belongs emphatically to the earlier ages of our globe, “is becoming gradually extinct, and presents in our days only some species very rare and few, especially when we compare them with the prodigious numbers of these beings which animated the seas of the ancient world.” It is a fact that the empty shells of the nautilus are more commonly found floating on the ocean than those which are inhabited. No doubt the living nautilus falls a prey either to larger marine animals, or, likely enough, to sea‐fowl. Is it not also possible that the lone animal, knowing the fate of its ancestors, and how they lie buried in barren strata, overwhelmed with melancholy apprehensions of his own future, jumps overboard and drowns himself? This suggestion is _not_ to be found among the recognised authorities. On the sea this scion of a decayed family is a graceful object, and in fine weather projects his head and tentacles, and takes a general inspection of the ocean. On land, however, he does not shine to so much advantage, for there he has to drag himself over the ground, head down and body and shell up. The shell has a regularly convoluted form, and is divided into cells; doubtless this it was that gave the idea to the inventor of water‐tight compartments. Through these passes a tube for respiration. In the outermost partition is the owner of the ship, covered by its mantle as a captain would be with pea‐jacket or sou’‐wester. The animal possesses numerous tentacles, and has two great eyes, enabling it to keep a good “look‐out.” The Pearly Nautilus, common in the Indian seas, is sometimes used for food. Its shell occasionally attains to a height of eight inches, and is said to be even now used by Hindoo priests as the conch with which they summon their followers to prayers. A very fine nacre is yielded, which is used in ornamental work. The Orientals make drinking‐cups of it, and adorn it with engraved devices. Many a retired old sea‐captain has such about his house to‐day; and before the world became so familiar with Asiatic productions they were often found in the houses of the wealthy.