Scientific American is the essential guide to the most awe-inspiring advances in science and technology, explaining how they change our understanding of the world and shape our ... Seashells are the exoskeletons of mollusks such as snails, clams, oysters and many others. ... The bone can grow and reshape continuously. read more
Sea shells are the hard outer covering, or exoskeleton, of certain mollusk species. These include your bivalves like clams, mussels, and scallops, as well as gastropods, which are snails. An example of a bivalve shell is the large white shell of sea clams often used as ashtrays. read more
Seashells are the exoskeletons of mollusks such as snails, clams, oysters and many others. Such shells have three distinct layers and are composed mostly of calcium carbonate with only a small quantity of protein--no more than 2 percent. These shells, unlike typical animal structures, are not made up of cells. read more
The sea shells in shops by the sea shore can be beautiful. They come in all sorts of shapes, sizes, and colors. There almost seems to be no end to the different kinds of sea shells you can find in these stores. read more