Barnaceles. VL 
exposed rocks, drift wood, and any other substance. 
Some of the mollusks affix themselves to the bodies 
of whales, others form a lodgment in the hollows 
of corals and sponges. Once fixed they remain so 
during life, taking their chance of such suitable 
food as may come within their limited sphere of 
action. At an earlier stage of their existence, 
both their shape and habits are very different, 
being lively little creatures, swimming about hither 
and thither like water-fleas. They are about the 
tenth of an inch long, and of most grotesque 
appearance, having six-jointed legs set with hairs, 
the whole being so arranged that they act in con- 
cert, and striking or flapping the water, send the 
little body along in a series of bounds; then the 
creature has two long arms, each furnished with 
hooks and a sucker, and a tail tipped with bristles, 
which is usually folded up under the body; its pair 
of large staring eyes are pedunculated, that is, set 
upon foot-stalks ; it has a house on its back, like a 
bivalve shell, into which it can collect its scattered 
members when occasion requires. When of suffi- 
cient age to settle itself in life, and become a staid 
member of submarine society, it fixes itself to some 
convenient object, throws away its eyes as no longer 
useful, gets rid of its preposterous limbs, enlarges 
