Perhaps the commonest representative of this family is the pretty little _Cypræa_ (_Trivia_) _europæa_ (Plate V.), the shells of which are sometimes washed up in large numbers on sandy beaches. The animal lives mainly below low-water level, but it may often be found in the larger rock pools, creeping rapidly over the tangles, and may be easily secured with the aid of a net. In the same family we have the little _Erato_ (_Marginella_) _lœævis_, the white shell of which is minutely furrowed along the lips; and also _Ovulum patulum_ (_Calpurna patula_), so called on account of its fancied resemblance to a poached egg. We have also several species of Cone shells (family _Conidæ_) on our coasts, readily recognised by their form, which is a cone, with a long, narrow aperture, partially closed by a minute operculum. As in the last family, the foot is abruptly shortened in front. The head is very prominent, with eyes situated on the tentacles. There are two gills, and the teeth are arranged in pairs. [Illustration: FIG. 179.--1. _Ovulum patulum._ 2. _Erato lævis_] [Illustration: FIG. 180.--_Mangelia septangularis_ AND _Mangelia turricula_] The Conidæ are principally inhabitants of tropical seas, where some very large species exist. Two of the British representatives, both common shells, are shown in fig. 180. Our next family (_Buccinidæ_) is so well distributed on our coasts, that it would be difficult, we imagine, to find a spot quite free from its familiar forms. It contains all those creatures commonly known as Whelks, Dog Whelks, and Dog Winkles, ranging from deep water almost to high-water mark. In all these the shell is notched in front, or the canal is turned abruptly upward. The foot of the animal is broad, the eyes are situated either on the tentacles or at their bases, and there are two gill plumes. All the species are carnivorous, and some are said to be very destructive to mussels and young oysters. The Common Whelk (_Buccinum undatum_, Plate V.) lives in deep water, whence it is dredged up largely for the market. Its clusters of egg cases are washed up in large numbers on the beach, where they form one of the commonest materials among the refuse at high-water mark. It is not uncommon, also, especially after storms, to find the unhatched eggs stranded by the waves, and these are so transparent that the embryos, several in each capsule, may be seen within. The hole through which the young escape may also be seen on the inner side. [Illustration: FIG. 181.--1. _Purpura lapillus._ 2. EGG CASES OF _Purpura_. 3. _Nassa reticulata_]