D O all the shell-fish feed on other shell-fish? Oh, no. Some of them live on seaweed. Some of them live by fishing. They catch, from the water, small bits of food, as small as grains of sand.
The shell-fish that lives on seaweed has a long, slim tongue. It is somewhat like that of the drill. The tongue is like a tiny strap.
The teeth are set on it, three or more in a row, like the points of pins. As the teeth wear out from work on the tough weed, more grow.
These shell-fish walk along on their one big foot. First one side of the foot spreads out, and then the other.
That pulls them along. Is it not very slow work? But what of that? All they have to do is to move about and find food. They can take all day for it. They have no houses to build and no clothes to make.
They creep along to a good bed of seaweed. Then they put out the fine, file-like tongue.
At Low Tide
It cuts off flakes of seaweed for them to eat. They are never tired of that one kind of food.
That queer limpet, who sits on a rock and has a shell like a cap, has a head, and a foot, and a tongue that is like a rasp. And he can walk along the floor of the sea.
He can climb up the rocks. The limpet has his own rock and his own hole in the rock. He goes back to his rock when he has had all that he wants to eat.
At Low Tide
The world of the sea is as full of life as the world of the land. There is one nice little shell-fish, not so big as a pea. He lives in the seaweed that grows on rocks. He is brown, or green, or black, or red, or dark yellow.
He can live in the damp weed in the hours when the tide is out, and has left the rocks dry. He eats seaweed. Let us look at him. He has two little feelers.
He has two wee, black eyes. He has a little snout, like a tiny pig. At the end of this snout is his little mouth. His small, dark foot has a dent in it.
He puts out his fine, file-like tongue, and laps it out and in, as a dog does when he drinks water. The sharp teeth cut off little scales of weed for him to eat. Take ten or more of these little shells in your hand. Each tiny animal draws in his tiny foot.
As the little animals hide in this way, put down your ear, and you will hear a faint squeak. It is made by the air in the shells.