Molluscs include all the shelled creatures of the seashore, with the exception of the barnacles. Molluscs are abundant in the region between high and low tide and are a major feature of all rocky ocean shores. Molluscs form one of the largest groups in the animal kingdom, with more than 80,000 known species. Molluscs form a very well defined group and although their outside features may vary greatly in form and colour, their internal structure is constant.
