Well Dressed.
I knew a boy who found a number of sea-eggs lying on the beach. He cried out, “Oh! look at all the chestnut burrs in the water!” The sea-egg when it is alive looks much like a chestnut burr, ripe, but not open. It is covered all over with thorns or prickles like the burr, and the water gives it the dark brown color.
Now let us look into this matter. You have read that a cross-star-fish has along the under edges of its rays many little tubes full of something like water. He can move them, and upon them he walks.
Undressed.
The sea-urchin has hard, sharp spines, which cover all the shell, and look like a rough coat. In the pictures you see the urchin with his shell bare, with his shell half bare, and with his full overcoat of quills. When the shell is bare, you will see upon it little lines of points or knobs. These are very pretty, but they are for use, rather than for beauty.
On every tiny knob is placed a spine, and the urchin can turn and move his spines, in all directions, just as easily as you can move your arm at the shoulder-joint.
When the urchin is alive, the quills stand out all about him. After he is dead, the quills drop off.
Between the rows of knobs are five double rows of holes, like pin-pricks. Out of these grow such little suckers as I told you the star-fish had.