Page:Natural History, Mollusca.djvu/224

 that the young Calyptrææ are developed under this sort of maternal roof, and do not quit it until they are in a condition to affix themselves, and are provided with a shell sufficiently hard to protect their own bodies."

Our other native genus of this family is said to manifest an instinct similar to this.

The Fools-cap Limpets, as the mollusks of this genus are called, have the shell shaped like a somewhat high cone, with the summit a little produced, and turned over backwards. The surface is commonly marked with lines (striæ), and covered with a horny skin, which is sometimes invested with a short velvety down. The interior has no plate or partition of any kind. The place of the attachment of the muscle is marked by a horseshoe impression. The animal has been already described.

The only British species is commonly known by the appellation of Torbay Bonnet (Pileopsis Hungaricus); it also bears the names of Fools-cap Limpet, Cap of Liberty, and Hungarian Bonnet, all of which designations, as well as both of its scientific ones, have an obvious reference to its form. It is a rather large shell, being frequently more than an inch and a half in diameter, and an inch in height. Its substance is rather thin, though strong, and somewhat translucent; its colour is a delicate pink, or flesh-white, though this is concealed, especially around the lower part, by an olive-coloured skin, covered with shaggy down.