The _Rachiglossa_ or marine carnivorous families lay their eggs in tough leathery or bladdery capsules, which are frequently joined together in shapes which differ with the genus. Each capsule contains a varying number of ova. The cluster of egg-capsules of _Buccinum undatum_ is a familiar object on all our sandy coasts. The capsules of _Purpura lapillus_ are like delicate pink grains of rice, set on tiny stalks. They are not attached to one another, but are set closely together in groups in sheltered nooks of the rocks. A single _Purpura_ has been observed to produce 245 capsules! _Busycon_ lays disc-shaped capsules which are all attached at a point in the edge to a cartilaginous band nearly 3 feet in length, looking like a number of coins tied to a string at equal distances from one another. In _Murex erinaceus_ the egg-capsules are triangular, with a short stalk. They are deposited separately in clusters of from 15 to 150, there being about 20 ova in each capsule. It appears that all the species of the same genus have by no means the same method of depositing their eggs, nor do they always produce eggs of at all similar size or shape. Thus, of two British species of _Nassa_, _N. reticulata_ lays egg-capsules in shape like flattened pouches with a short stalk, and fastens them in rows to the leaves of _Zostera_; _M. incrassata_, on the other hand, deposits solitary capsules, which are shaped like rounded oil-flasks. _Neptunea antiqua_ lays its eggs in bunched capsules, like _Bucc. undatum_ (Fig. 40), but the capsules of _N. gracilis_ are solitary. [Illustration: FIG. 39.--Various forms of spawn in _Prosobranchiata_: =A= and =D=, _Pyrula_ or _Busycon_; =B=, _Conus_; =C=, _Voluta musica_; =E=, _Ampullaria_ (from specimens in the British Museum); all × ⅔.] In _Natica_ the eggs are deposited in what looks like a thick piece of sand-paper, curled in a spiral form (Fig. 41). The sand is agglutinated by copious mucus into a sort of sheet, and the eggs are let into this, sometimes (_N. heros_) in regular quincunx form. _Ianthina_ attaches its eggs to the under side of its float (Fig. 42). The Trochidae deposit their eggs on the under side of stones and sea-weeds, each ovum being contained in a separate capsule, and all the capsules glued together into an irregular mass of varying size. The female of _Galerus chinensis_ hatches her eggs by keeping them between her foot and the stone she adheres to. They are laid in from 6 to 10 capsules, connected by a pedicle and arranged like the petals of a rose, with 10 to 12 eggs in each capsule. Those _Littorina_ which are not ovoviviparous deposit their spawn on sea-weeds, rocks, and stones. The eggs are enveloped in a glairy mass which is just firm enough to retain its shape in the water; each egg has its own globule of jelly and is separated from the others by a very thin transparent membrane.[242]