“On approaching near, it was observed to be the shell-fish, commonly known by the name of the [Pearly Nautilus]: it was captured and brought on board; but the shell was shattered from having been struck with the boat-hook, in taking it, as the animal was sinking when the boat approached, and, had it not been so damaged, it would have escaped. I extracted the fish in a perfect state, which was firmly attached to each side of the cavity of the shell.” The hood has been stated by Dr. Shaw, as being “of a pale, reddish-purple colour, with deeper sports and variegations,” the colour, however, as it appeared in this recent specimen, was of a dark reddish-brown.

SHELL OF THE NAUTILUS; AND THE SEA-PEN,
OR INTERNAL SHELL OF THE LOLIGO.

Although this is the only instance of the animal itself having been brought to this country, there is but little doubt of its having been frequently taken, but as the shell was the object of the captors, and not its inhabitant the latter has been thrown away as useless. An office in his Majesty’s Navy found a Nautilus in a hole in a reef of rocks, near an island on the Eastern coast of Africa; the mantle of the fish, like a thin membrane, covered the shell, which was drawn in as soon as it was touched, and the elegant shell was then displayed. “I and others,” says the same informant, “when it was first seen did not notice it, regarding the animal, as the membrane enveloped the shell, merely as a piece of blubber; but having touched it by accident, the membranous covering was drawn in, and we soon secured our beautiful prize.”

Rumphius, a German naturalist, appears to have been acquainted with its habits; he says, “When he thus floats upon the water, he puts out his head, and all his barbs, and spreads them on the water, with the poop of the shell above water: but at the bottom he creeps in a reverse position, with his boat above him, and with his head and barbs upon the ground, making a tolerably quick progress. He keeps himself chiefly on the ground, creeping sometimes also into the nets of the fishermen: but after a storm, as the weather becomes calm, they are seen in troops floating on the water, being driven up by the agitation of the waves. This sailing, however, is not of long continuance, for having taken in all their tentacles, they upset their boat, and so return to the bottom.”

ORDER TRACHELIPODA.

The Trachelipodes contain by far the largest portion of the univalve shells, and are mostly inhabitants of the waters. They form two numerous groups, the feeders on animal food, (Zoophagi,) and those that exist on vegetable substances, (Phytophagi.) The animal feeders are well distinguished from the other group, by having a mouth without jaws, being furnished with a tube which they can retract or advance at pleasure, for the purpose of sucking their nutriment from the bodies of other inhabitants of the deep. The animal feeders are also known from the other section by the possession of a projecting tube called a siphon, which conveys the water to the gills. The shell also points out to which section its possessor belonged, from the lower part of its opening being formed either into a sort of canal, or a groove for the reception of its siphon. They are all marine animals, and breathe water. The flesh-eating tribes compose five families.

Family CONVOLUTA.

The convoluted shells contain but few genera; but these are very rich in species, and furnish us with some of the most beautiful specimens of this class.