MR. BARNACLE AND HIS SON.
The Barnacle has a name which means hair or ringlet-footed. People thought his little fine curled-up feet looked like small curls of hair. His body is like a small bag or sac, with the six pairs of little curly feet placed at one end. The body is made of rings as are the bodies of insects. All the six pairs of legs are on the chest rings. Each leg has two joints, and a little branch like a fine fringe. The hard shelly cover of the barnacle is made of plates lapped together. When they are closed they look something like buds on trees, or young pine cones. When the fringes of the feet wave out between the edges of the shell-plates, it looks as if the buds were about to open into flower.
A barnacle is more like his far-off cousin Mr. Crab when he is little than when he is grown up. Every grown-up barnacle must be firmly fastened upon some other body. The barnacles are divided into two classes, according to the way in which they are fastened upon objects: 1. Stem Barnacles, 2. Stemless Barnacles.
A stem barnacle has plates which form a three-cornered shell. It grows fast to some object by a small stem which is soft, and can bend about easily.
A stemless barnacle has a shell shaped like an acorn, or like a rosebud with the top bitten off. Instead of a stem, it is held fast to the object on which it grows by a thin plate of shell at its broad, or flat end. This plate has a tiny hole in the centre.
When you first saw a barnacle, you would not think it was any relative of Mr. Crab. When grown up it does not look at all like the Crab Family. When crabs and barnacles are very young, they look more like each other.
Old and Young Barnacles.
Let us look at an acorn barnacle. The shell is in plates, as if two or three shells were set one over another. The shell grows by added bits of lime, as a conch shell does. The thin skin that lines it, and holds it together, is shed, like Mr. Crab’s coat. Then the shell has room to grow.
The shell is hard and white. It is lined with a very thin skin, which often has a faint, pretty tint.