NAUTILUS. 291 NAVAHO. Tlie body is slioit and tliick, diviiled into a largu obtusely conical head bearing eyes, ten- tacles, ears (otocysts), an<l a rounded sac-like trunk. The mouth is surrounded by abuul 90 ex- ternal filiform tentacles. The pair of tentacles on the inner or dorsal side are fused so as to form a hoodlikc lobe by which tlu' aperture of the shejl is closed when the animal is withdrawn into the PKABLY NAUTILUS (Anutllu.^ i-..,.., ( Seen in section showing the chambers and eiphuucle, 8ize. ) living chamber. Beneath is the funnel (hypo- nome ) , not forming a completely closed tube as in the squids, but a locomotive organ, through which, as in other cephalopods, the water is ejected with sufficient force to throw the ani- mal backward. In swimming forward, says Kent, the tentacles are extended radially from the head. The mouth is in the centre of the lobes and groups of tentacles, armed with a tongue (ra- dula) and a pair of remarkably powerful horny jaws tipped with carbonate of lime. Olfactory organs and osphradia are present. The animal is attached within the living chamber by two oval muscles. The compartments of the .shell are usually said to be filled with air or gas, but according to Verrill they are filled with sea- water, which may be taken in or expelled so as to equalize pressure at varying depths. Until recently the living nautilus was exceed- ingly rare, though the empty shells are cast ashore in great quantities in the Pacific and Indian oceans. Yet they have been for a long time trapped in baskets like lobster-traps by the na- tives of sojue of the Melanesian and Fiji islands and used as food. Willey at Ralnm. in Xew Britain, succeeded in trapping the nautilus in 70 fathoms of water. He also succeeded at Lifu, one of the Loyalty Islands, in capturing speci- mens at a depth of only three fathoms. These he kept in a large submerged cage, feeding them daily until his efforts were rewarded early in December, 1894. by finding that they had spawned in the cage, yielding an abundance of eggs. These are not laid in bimches. as is the case with (Half natural Fossil N.utili. Although the family Xautilidas dates from the Jurassic period, the genus Nauti- lus is doubtfully referred to the Tertiary'. The order Nautiloidea. however, originated as early as the Ordovician; the earlier types were straight and uncoiled, like Orthoceras. ery striking, says Hyatt, is the uuirvelously sudden rise of the Xautiloidea as a group; it reached its maximum in the Silurian, followed by a decline extending from the Devonian to the Triassie period. Then the forces acting unfavorably upon their existence were arrested, or their violence lessened, and the group has been affected by only very slight changes and an exceedingly slow process of retrogression, until the present time. Bibliography. Owen, Memoir on the ['early Kaiitilus (London. 1832) ; Par- ker and Haswell, Text-bonk of Zoology (New York, 1898) ; Cooke, Jlollusks (Cambridge Natural Historj', ib., 1895) ; Hyatt, in Zittel-Eastman. Textbook of f'aleuntoloijy ( ib., 1900) ; Willey, "Pearly Nautilus" (Zooloyieal Results Based on Material from Xew Britain, Xew Guinea, etc.. Cambridge, England, 1902 ; vi.. Zoology). NAUVOO, na-voo'. A city in Han- cock County, 111., 12 miles north of Keokuk, Iowa ; on the Mississippi River, at the head of the lower rapids (Map: Illinois, A3). It is in a highly productive fruit-growing country, where the leading occu- pations are wine-making and the culture and shipment of fruit for market, particularly grapes and berries. Saint Mary Academy, conducted by the Benedictine Sisters, is in Nauvoo. The most interesting features in this vicinity are the remains of the old ilormon buildings. Popula- tion, in 1890. 1208: in 1900, 1321. Nauvoo was founded by the Mormons in 1840, and rapidly in- creased in size until in 1846 it had a population of 15,000. In this year the settlement was broken up by the people in the neighborhood. (See MoRiiON.s.) .
imposing temple, 130 feet
long by 90 feet wide, left unfinished by the Mor- mons, was destroyed partly by tire in 1848 and partly by a tornado in 1850. In 18.50 a company of French socialists, called Icarians (q.v.), under the leadership of M. Cabet, occupied Nauvoo, but their experiment jn-oved a failure, and the}' abandoned the place in 1857. NAVA, nii'vi'i. A seaport of .Japan. See Nafa. NAVAHO, or NAVAJO. Sp. proii. na-va'H.V An important tribe of Athapascan stock (q.v.). Their present reservation in n(utheastern .Ari- zona and extending into New Mexico and Utah comprises nearly ten million acres, but it is almost entirely an arid desert of sand and rock, unfit for any purpose except scanty grazing. Like other tribes of the same stock, they call them- selves simply Dine, 'people;' they are called Apaches dc Navajo in Spanish records at least those of the squid, but are deposited separately as early as 1G30. They came originally from the by the female. Each egg is as large as a grape. There are said to be three species now living in the Pacific Ocean, while the number has been (arried up to even four. The two better known species are yautiUis pompilius and Nautilus urn- hiliratus. far northern home of their kindred, but have incorporated elements from all the neighboring tribes. They were roving and predatory in their habits, and were continually at war with the LHe and the Plains tribes. They were alternately at war or peace with the Spaniards during the early
