Shell-fish

(, then, grow in the way above mentioned; and some
of them grow in shallow water, some on the sea-shore, some in rocky
places, some on hard and stony ground, and some in sandy places.) Some
shift about from place to place, others remain permanent on one
spot. Of those that keep to one spot the pinnae are rooted to the
ground; the razor-fish and the clam keep to the same locality, but are
not so rooted; but still, if forcibly removed they die.

(The star-fish is naturally so warm that whatever it lays hold
of is found, when suddenly taken away from the animal, to have
undergone a process like boiling. Fishermen say that the star-fish
is a great pest in the Strait of Pyrrha. In shape it resembles a
star as seen in an ordinary drawing. The so-called 'lungs' are
generated spontaneously. The shells that painters use are a good
deal thicker, and the bloom is outside the shell on the surface. These
creatures are mostly found on the coast of Caria.)

The hermit-crab grows spontaneously out of soil and slime, and
finds its way into untenanted shells. As it grows it shifts to a
larger shell, as for instance into the shell of the nerites, or of the
strombus or the like, and very often into the shell of the small
ceryx. After entering new shell, it carries it about, and begins again
to feed, and, by and by, as it grows, it shifts again into another
larger one.