_Cephalodiscus dodecalophus_[45] was found in the Straits of Magellan, during the "Challenger" voyage, at a depth of 245 fathoms, and has recently been rediscovered in shallower water in the same neighbourhood by the Swedish Antarctic Expedition. Another _Cephalodiscus_, at present undescribed, has been obtained by Dr. Levinsen from 100 fathoms off the coast of Japan; while the Dutch expedition carried out by the "Siboga" has resulted in the discovery of two other specimens, one from a reef close to low-tide mark on the coast of Borneo, the other from 41-52 fathoms off Celebes. These three specimens differ markedly from one another and from the "Challenger" specimen of _C. dodecalophus_, and it is probable that they all belong to new species. The occurrence of a deep-sea animal at a great distance from the locality at which it was first found is not in itself a matter for great surprise; but in the present instance two of the newly discovered forms are from shallow water, and one of them is actually littoral. The occurrence of so many species of _Cephalodiscus_ in Oriental waters suggests that the Pacific or the Indian Ocean may be the headquarters of the genus, which may prove to be far less of a rarity than has hitherto been {24}supposed. There is evidence derived from the results of the "Siboga" expedition that abyssal animals may migrate into comparatively shallow water in the Malay Archipelago. _Cephalodiscus_ and _Rhabdopleura_ are remarkable for their power of producing buds. In the former these arise from the apex of a stalk which is given off on the ventral side of the body, and they break off when they reach a certain age; in the latter they do not become free, and a colony results, which consists of a creeping "stolon" from which vertical branches are given off at intervals, each ending in an individual of the colony. _Cephalodiscus_ forms a gelatinous "house" (Fig. 9, A), in the passages of which are found large numbers of the free individuals, together with their eggs and embryos. _Rhabdopleura_ (Fig. 12) is protected by cylindrical tubes, one of which corresponds with each individual. [Illustration: FIG. 10.—Longitudinal median section of _Cephalodiscus dodecalophus_. _a_, Anus; _b.c_^1, _b.c_^2, _b.c_^3, first, second, and third body-cavities; _int_, intestine; _m_, mouth; _nch_, notochord; _n.s_, central nervous system; _oes_, oesophagus; _op_, operculum, the ventro-lateral part of the collar; _ov_, ovary; _ovd_, pigmented oviduct; _ph_, pharynx; _p.p_, proboscis-pore; _ps_, proboscis; _st_, stomach; _stk_, stalk.]