1. THE LIMPET.2. THE KEY-HOLE LIMPET.
3. THE SMOOTH LIMPET.4. THE CUP AND SAUCER LIMPET.
PLATE XII
THE PAINTED TOP (1)
Tops are generally very common indeed on the sandy parts of the shore. You cannot possibly mistake their shells for those of any other creatures, for they are cone-shaped, looking very much like rather flattened sugar-loaves, and are generally very beautifully coloured. So pretty are they, indeed, that they are sometimes strung together and worn as necklaces, or used for ornamenting ladies’ dresses.
The painted top is one of the most beautiful of all these shells, for it is covered all over with spots and streaks and blotches of scarlet, and crimson, and pink, and purple, and white, and blue, and yellow! But all this lovely colouring is only on the outer coat of the shell, which is very easily chipped off. The consequence is that these shells are very often damaged by being tossed to and fro by the waves, and though you may often find twenty or thirty in the course of a morning, not more than two or three, perhaps, will be quite uninjured.
Tops are very useful creatures to have alive in an aquarium, for they keep the glass sides clean from the tiny green weeds which so quickly grow upon them. They do this by means of their tooth-ribbons, and you may see them crawling about on the glass walls and mowing down the weeds, just as a gardener cuts the grass on the lawn with his scythe.