In some places, where the sea is not agitated by winds, great numbers
of these singular creatures may occasionally be seen sailing and
sporting about. Le Vaillant observed several of them on the sea near
the Cape of Good Hope; and, as he was desirous of obtaining perfect
specimens of the shells, he sent some of his people into the water to
catch them; but when the men had got their hands within a certain
distance, they always instantly sank, and, with all the art that could
be employed, they were not able to lay hold of a single one. The
instinct of the animal showed itself superior to all their subtlety;
and when their disappointed master called them away from their
attempts, they expressed themselves not a little chagrined at being
outwitted by a shell-fish.