Another interesting fact concerning the development of this ornamentation is that the smoother shells inhabit rocky shores where the waves are constantly beating in with greater or lesser violence, while the more spiny individuals live in protected and comparatively still water. This adds additional weight to the theory expressed in the last paragraph, for the fish which feed upon these shells do not, as a rule, inhabit localities where the water is rough, as along a rocky shore, but live abundantly in protected bays and lagoons in which the spiny murices are found. There are shown on the plate eight species of rock shells, all more or less common. The first one for us to consider may be called Venus' Comb, (_Murex tribulus_) and is found in China, Japan and the Indian Ocean. It belongs to a group of shells which is characterized by a long snout or canal, and long, pointed spines. The color is yellowish; in one variety the spines are tipped with black. A shell which is found on the mantel in every household is known as the Branched Rock Shell (_Murex ramosus_), which is widely distributed, being found in the Red Sea, the Indian Ocean, New Zealand, Australia and the Central Pacific Ocean, and attains a large size, some specimens reaching the length of a foot and weighing several pounds. The aperture is frequently tinged with a deep, beautiful pink. In many households the large shells of this species are used for flower pots, suspended from a hook over the window by a set of chains, and for this purpose they are certainly very ornamental. The Apple Murex (_Murex pomum_) is of home production, being found on the shores of Florida and throughout the West Indies. It is not as attractive as the shells just mentioned, but is very common, every collector possessing several specimens in his cabinet. In the aperture of this species will be noticed a dark brown object which is known as an operculum or door, and its use is to close the aperture when the animal withdraws into its shell, so that the latter may be safe from its enemies. All of the rock shells possess this organ, which is attached to the back part of the animal's foot. A peculiar and somewhat rare shell is the Horned Murex (_Murex axicornis_), found in the Indian Archipelago, whose shell is made up of many curiously fluted spines. The Burnt Murex (_Murex adustus_), is an inhabitant of the Indian Ocean, Japan and the Philippines, and its name, which signifies burned, is well chosen, for all its spines and frills and most of the shell are black in color and look just as though the shell had been scorched. The aperature is often beautifully tinged with pink or dark red.