Elementary text-book of zoology, general Elementary text-book of zoology, general part and special part: protozoa to insecta elementarytextbo00clau Year: 1892 OSTEACODA. 427 pose. In addition a large copulatory organ, which may be dex-ived from a modified pair of appendages and often possesses a very compli- cated structure, is always present. The male genital organs consist on either side of several elongated or globular testes, of a vas deferens and the copulatory organ ; the presence in Cypris of a very peculiar paired mucous gland and the size and form of the spermatozoa seem to be worthy
Elementary text-book of zoology, general Elementary text-book of zoology, general part and special part: protozoa to insecta elementarytextbo00clau Year: 1892 OSTEACODA. 427 pose. In addition a large copulatory organ, which may be dex-ived from a modified pair of appendages and often possesses a very compli- cated structure, is always present. The male genital organs consist on either side of several elongated or globular testes, of a vas deferens and the copulatory organ ; the presence in Cypris of a very peculiar paired mucous gland and the size and form of the spermatozoa seem to be worthy of notice (Zenker). The female of Cypris possesses two ovarian tubes which project into the reduplicature of the carapace, two receptacula seminis, and the same number of genital openings at the base of the abdomen. Development.—The greater number of Ostracoda lays eggs, which they either attach to watei'-plants (CyjJris), or, as in Gyj)rid'ina, ciirry about Avith them between the shell valves until the young are hatched. The free development of Cypris consists of a complicated metamorphosis. The lai-voe, when hatched, possess, like the Nauplius form, only three pairs of appendages, but are strongly compressed laterally, and are already enclosed in a thin bivalve shell (fig. 338). In the marine Ostracoda the development is simplified, so that the metamorphosis is entirely absent. The Ostracoda feed altogether on ani- mal matter, as it seems especially on the carcasses of different aquatic animals. fig. 338.—Very youns larva of Numerous fossil forms are known from y^^- Naupiius stage with three \ airs of appendages. almost all formations, but, unfortunately, M, stomach; D, mtcstine; only the remains of their shells are pre- f^' tcLTltL'J'.f'ij! served. mandible. Cijpridlna. With heart and large movable paired eye. With deep excava- tion in the edges of the shell for the passage of the antennae. The anterior antennfe are bent, furnished with strong sette, and have olfactory
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