OCEANIC DEPOSITS. 727 OCELOT. a rule the coarser materials occur in the sliallow marginal waters, while the tine sands and nuuls are found in the deeper portions, where they have been carried l)y the drifts and currents. In the free ocean the character of the bottom shows little variatiim over great areas. When the deptli is comparatively slifjht the deposits con- .sist of the shells of minute organisms tluit live at or near the surface, of volcanic dust, bones and teeth of tish, and chemical pri'cipitatcs. The most widespread and characteristic material in the tropical and temperate regions is globigerina ooze, an accumulation of the fossil calcareous casts of foraminifera. In the colder Avaters, such as those of the South Atlantic and the Southern Ocean, the principal organisms are of siliceous character, and their remains compose the diatom ooze that is so characteristic of those regions. When the floor lies at a depth of 2500 fathoms or niiu'e, only the most refractory materials can resist the solvent action of the water, and the deposits take the form of a red or brownish clay com]iosed of the insoluble portions of shells, mixed with meteoric and volcanic dust. These deposits cover great areas in the middle portion of the Atlantic and the northern part of the Pacific Ocean. See Ocbian ; Deep-Se.4. Explora- tion : Ooze, etc. OCEANIC FAUNA. See Deep-Se. Explo- RATiox ; iiuzE; Pelagic Animals. OCEANIDS {GkmKmvlikc, Okeanides). The thrcn- thou-and daughters of Oceanus and Tethys, nymphs of the sea. OCEAN LIFE. Ocean life embraces the great company of nuirine animals, which includes rep- resentatives of every phylum. It appears certain that life originated in the ocean (see Protozoa), and for a long period at the beginning of the living world remained there exclusively, develop- ing a wide variety and considerable advancement in organization before living beings obtained any footliold on din- land. Great numbers of low- forms remain in the oceans (see Pelagic Ani- jials; Ooze) in substantially the primitive form and condition, owing to the comparative immuta- liility of their environment. Some are very wide- ly distributed, others kept within narrow bounds liy inability to dwell except under accustomed conditions of temperature, pressure (according to depth), or within definite food-yielding areas. Great numbers are fixed and stationary in adult life. Hence zones and areas of distribution, both lateral and vertical, exist. (See DiSTRinuTiON of Animals.) That the land was populated jiri- marily from the sea is conceded bv all natural- ists; it is also true that many creatures once terrestrial have been relegated to a wholly ma- rine existence by force of circumstances acting I through long past ages, a conspicuous example
- of w-hieh is the group Cetacea (q.v.). See Deep-
Sea I'.xim.okation. O'CEANOGTRAPHY (from •'.•Kravdc, oUennos. ocean + -y/iaipiaj -grnphia, description, from ypaiptiv, (irnphcin, to write). The name given to the branch of geography which deals with the phenomena of the collected waters of the earth — the oceans and seas. The name has only recently come into general use. as a result of the great i>pansion in our knowledge concerning the ocean during the last thirty years. See Deep-Sea Exploration; Ocean; Geoorapht. OCE'ANtrS (Lat., from Gk. 'QKcnvdr,, Okea- 510.S). In classical mythology, the eldest of the Titans, son of Uramis and (ia'a, and father, by his sister Tethys, of the 3000 Oceanids, or ocean nymphs. In Homer Oceanus is the ever-flowing stream which surrounds the circular plain of the earth. From him come all streams and fountains, and even the sea. Ilesiod first giA'cs the accepted genealogy. He does not apjjcar in an- of the myths as a governing personality like Poseidon, but only as a spectator. In the I^ rum el he us liuuiul, .Eschylus introduces him as advising the captive to submit to Zeus. Representations in art are very rare before the Hellenistic period, when he is depicted, like the river gods, as a bearded man, often with horns, and is charac- terized by the steering oar, or the sea animals surrounding him. OCEL'LUS LUCATSrUS (Lat., from Gk.'0«f;t- Adf, Ohcllos). A Lucanian Greek and member of the Pythagorean School; perhaps of the fifth century B.C. Stobaeus, i. 13, has preserved a fragment of his work in Dorian dialect: and we hear of various philosophical writings w-hich have now been lost. The extant work On the Nature of the Universe (Ilcpl rf/q rov navro; <tijmuq) in the Ionic dialect, w-hich bears Ocel- lus's name, is certainly a work of the later Peripatetic School, and cannot be earlier than the first century B.C.; it may be still later, as it shows remarkable coincidences with the similar work of Xicolaus Dama-cenus. In four chapters the book handles the themes of the eternity of the cosmos, the distinction between the per- manent and the transitory, the divisions of the universe, the heavens, earth, and the human race, the nature of time, etc.. all being based on the writings of Aristotle. The work closes with a consideration of the relation of the propagation of humankind to certain cosmic and moral ques- tions. It is best edited in vol. i. of Mullach's Fragmcnia Philosopliornm (Ircecorum (Paris, 1800) ; English translation by Thomas Taylor (Lonilon, 1831). OCELOT, 6'se-lot (Mexican ocelotc). A beau- tiful wild cat {Fetis pnrdeilis) of tropical Amer- ica, from Louisiana to Brazil. It inhabits forests, is an agile tree-climber, and preys mainly on birds. It is from two feet six inches to three feet long, exclusive of the tail, which is from II to 15 inches, and nearly of uniform thickness. The ears are thin, .short, and jiointed. The muz- k^'^^k THE OCELOT. zle is rather elongated. The colors varv con- siderably, but tile griiiind tint is rich reddish gray or tawny, blending finely with the dark brnwii on the margins of the elongated spots, of which there are chains on the sides; the head, neck, and legs being also variously sjiotted or
