TURBELLARIA, in zoölogy, an order of Platelminthes; flat worms of low organization, ribbon-shaped, leaf-shaped, oval, broad, or long, inhabiting fresh or salt water, or damp localities on land. The smallest are not larger than some of the Infusoria, which they approach in appearance, while the largest are many feet long. Only one genus, Alaurina is divided into distinct segments, and the outer surface of the body is everywhere beset with vibratile cilia. The aperture of the mouth is sometimes situated at the anterior end of the body, sometimes in the middle, or toward the posterior end of its ventral face. In many the oral aperture is surrounded by a flexible muscular lip, which sometimes takes the form of a protrusile proboscis. All have water vessels, opening externally by ciliated pores, and pseudhæmal vessels; most possess eyes, and some have auditory sacs. Some are monœcious, and others dioecious; in most the embryo passes by insensible gradations into the form of the adult, but some undergo a remarkable metamorphosis. The Turbellaria are variously divided by different authors. Huxley divides them into Aprocta (having no anal aperture) and Proctucha (having an anal aperture). The first group contains the Rhabdocæla and Dendrocæla of other authors; the second is equivalent to the Rhychocæla or Nemertea.
TURBINE. The common water turbine is an application of the water-wheel, and may be said to consist of a motor, water-driven. In its simplest form, it is a wheel, fitted with a number of buckets, or vanes, against which a stream of water is caused to flow, thus producing rotation of the wheel. In modern machines, however, this simple principle has been developed in a number of ways. In some turbines, there are tiers of buckets, one above the other, while in turbines of the “vortex” type, the vanes are radial, and the water is admitted to the center of the wheel and flows outward. In a third type, the so-called “mixed flow” principle is used, the water being admitted at right angles, and also parallel to the axis of rotation. Water turbines are largely used for driving dynamos in converting water-power to electric-power. See Steam Turbine.
TURBOT, in ichthyology, Rhombus maximum, the most highly valuable of the Pleuronectidæ, or flat fishes, for the table. The turbot is a broad fish, scale-less, with numerous flattened, conical tubercles on the upper side; the lower eye is a little in front of the upper eye, and the lateral line makes a semicircular curve above the pectoral fin. In color it varies from gray to brown, often with spots of a darker hue. Turbot are migratory fish, traveling in companies where the bottom is sandy. They feed chiefly on small fish, crabs, and shell fish; but the bait used is always some fish of bright color and tenacious of life, for, though turbot are very voracious, they will never touch a bait that is not perfectly fresh. Weight from 5 to 50 pounds. In the English Channel turbot are taken by trawling. The turbot was known and prized by the Romans, and the fourth satire of Juvenal celebrates the fact that Domitian convoked the Senate to decide how a monster turbot that had been brought to him should be cooked.
TURCO-ITALIAN WAR. The acquisition of territory in north Africa by France shortly after the Franco-Prussian War had created deep resentment in Italy, which feared the loss of prestige on the Mediterranean. Especially alarming to Italy was the seizure of Tunis in 1881, by France. This incident, more than any other single factor, led Italy to enter the Triple Alliance (q. v.) with Austria and Germany. Thus protected, Italy set forth to acquire possessions in Africa, in rivalry with France. To weaken the Triple Alliance, however, France hastened to arrive at an agreement with Italy over their separate spheres of influence in Africa. Thus doubly strengthened, Italy declared war against Turkey on Sept. 29, 1911, choosing that time probably because of the disorder in the internal affairs brought about by the Young Turk Revolution. Italy immediately landed troops in Tripoli, and Cyrenaica, which was the territory in Africa coveted. Here the war was fought out, and because of the difficulty of the Turks in bringing troops to this distant possession, the Italians were able to gain a long series of victories. On Oct. 18, 1912, Turkey signed a treaty surrendering this territory to Italy, at Lausanne, Switzerland. Throughout the war all the other European countries had maintained an attitude of strict neutrality, with the exception of Russia, which had vetoed the Italian plans for an attack on the Dardanelles. There can be no doubt that Turkey would not have signed the Lausanne treaty had it not been for the fact that already Montenegro had fired the first shot of the campaign of invasion already threatened by the Balkan states.
TURENNE, HENRI DE LA TOUR D’ AUVERGNE, VICOMTE DE, a French military officer, second son of Henri,