NEMEAN GAMES. See GAMES, vol. x. p. 65.

NEA.IERTINES, or NEMERTEANS (Nemertea), is the name of a subdivision of worms,' characterized by the ciliation of the skin, by the presence of a retractile proboscis, by the simple arrangement of the generative apparatus, and in certain cases by a peculiar pelagic larval stage to which the name " pilidium " has been given. Many of them are long thread-shaped or ribbon-shaped animals, more or less cylindrical in transverse section. Even the comparatively shortest species and genera can always be termed elongate, the broadest and shortest of all being the parasitic Malacobdella and the pelagic Pelagonemertes. There are no exterior appendages of any kind. The colours are often very bright and varied. They live in the sea, some being common amongst the corals and algre, others hiding in the muddy or sandy bottom, and secreting gelatinous tubes which ensheath the body along its whole length. Formerly, they were generally arranged amongst the Platyelminthes as a suborder in the order of the Turbellarians, to which the name of 1?hynchoccela was applied, the other suborders being the Dendrocoda and the Rhabdoccela. With the advance of our knowledge of these lower worms it has been found desirable to separate them from the Turbellarians and to look upon the Nemertea as a separate phylum of Platyelminthes. Lately the interest in their morphology has increased, since it has been advanced (6, 8)2 that certain points in their organization appear to indicate a remote degree of relationship to the ancestral forms which must have preceded the Chordata (to which the vertebrate animals also belong), and that this relationship is closer than that which exists between those Protochordata and any other group of invertebrate animals.