I this day preserved one of these with its swimming apparatus expanded.
3.

An animal without a shell, which had a sort of transparent horny covering, and when alarmed and not in motion folded itself up.
4.

A tube 3.2 inches in length, perfectly transparent, and swelling out to a little knob at each extremity; but these knobs were of the same colour as the body.
5.

Some delicate white shells (Atalanta) or very hard gelatinous animals, 0.2 inches in length, 0.2 wide, and 0.15 thick; they had three ridges of short spines on them, one down each edge, and one ridge running down the centre of the shell or back.
6.

Some perfectly spherical transparent bodies, 0.18 inches in diameter; these neither moved nor showed any signs of life when placed in salt water, but another animal, exactly resembling them in shape and colour, with the exception of having some light brown spots on it, unrolled itself like a wood-louse, and then swam nimbly about.