[Illustration: FIG. 40.--Egg-capsules of, =A=, _Nassa reticulata_ L. × ⅔; =B=, _Buccinum undatum_ L. × ⅔; =C=, _Neptunea antiqua_ L. × ⅓.] [Illustration: FIG. 41.--Spawn of a species of _Natica_ (from a specimen in the British Museum) × ½.] [Illustration: FIG. 42.--_Ianthina fragilis_ Lam. =FL=, float; =O=, ova; =Pr=, proboscis; =Br=, branchiae; =F=, foot. (Quoy and Gaimard.)] _Chiton marginatus_, when kept in captivity, has been noticed[243] to elevate the posterior part of the girdle, and to pour out a continuous stream of flaky white matter like a fleecy cloud, which proved to be of a glutinous nature. It then discharged ova, at the rate of one or two every second, for at least fifteen minutes, making a total of 1300 to 1500, each being about 1/100 inch diameter. The ova were shot into the glutinous cloud, which seemed to serve as a sort of nidus to entangle the ova and prevent them being carried away. The subsequent development was rapid, and in seven days the young _Chiton_ was hatched, being then about 1/20 inch long. Lovén has described the same species as laying its eggs, loosely united in clusters of seven to sixteen, upon small stones. There is probably some mistake about the identification, but the observation illustrates the varying methods of oviposition among allied forms. [Illustration: FIG. 43.--Egg-capsules of =A=, _Sepia elegans_ Orb., and =B=, _Octopus vulgaris_ Lam.] Not very much is known with regard to the ovipositing of the _Cephalopoda_, especially those which inhabit deep water. Masses of ova arranged in very various forms have occasionally been met with floating in the ocean, but it is next to impossible to determine to what species, or even genus, they belong.[244] In _Loligo punctata_ the ova are contained in small cylindrical cases measuring 3 to 4 in. by ½ in., to the number of about 250 ova in each case. Hundreds of these cases are attached together like a bundle of sausages or young carrots, and the movements of the embryos within can be distinctly noted. _Sepia officinalis_ lays large black pear-shaped capsules, each of which is tied to some place of attachment by a kind of ribbon at the upper end of the capsule, the whole forming a large group like a bunch of grapes. _Octopus vulgaris_ deposits thousands of small berry-shaped ova, attached to a string which runs along the centre of the mass (Fig. 43). The so-called shell of the female _Argonauta_ is nothing more than a form of protection for the ova, and is in no sense homologous to the ordinary molluscan shell. The ova consist of a large granulated mass, attached to a many branched stem; they are contained in the spire of the shell, in contact with the posterior part of the body of the mother, but sometimes project externally beyond the coil of the spire.