(Span. Tejo, Port. Tejo), the largest river in the Iberian peninsula, which it traverses from east to west, and divides into two nearly equal parts. It rises in the Sierra Molina, on the borders of the Spanish provinces of Cuenca and Teruel, and flows at first in a north-east direction, separating the former of these provinces from that of Guadalajara. After receiving the Molina from the north-east, it turns to the south-west, and about 50 miles lower down receives the Guadalida, on the frontiers of the three provinces of Cuenca, Guadalajara, and Madrid. It continues to flow south-west until it enters the more open country in the province of Toledo, where it takes an irregular westerly direction, and traverses the fertile and well-peopled table-land of central Spain. In this part of its course, the Tagus receives the Jarama with its affluent the Tajuna, and further down the Guadarama and the Alberche, all from the north. The tributaries which join it from the south are of much smaller size, as the Sierra de Toledo on that side approaches much nearer to the river than the Sierra de Guadarama on the north. The Cedron is the chief affluent that the Tagus here receives from the south. After traversing the province of Toledo the river enters that of Maceres, where it is joined by the Alagon from the right, a river which brings down from the mountains such a volume of water as to render the united stream navigable from the sea up to the confluence at Alcantara. Above this point the Tagus cannot be navigated, owing, in some measure, to the rapidity of its current through narrow valleys, and it forms rapids of great length. Below Alcan-

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1 Vopiscus, Tac. Imp. c. x. Tahiti Tara it begins to turn towards the south-west, and for some distance forms the boundary between Spain and Portugal, finally entering the latter country, in which it separates the provinces of Bara and Alentejo, and after traversing that of Estremadura, falls into the Atlantic by a wide estuary which forms the port of Lisbon. The chief affluents of the Tagus in Portugal are the Zezere from the right, and the Zatas from the left. Its whole length is estimated at 540 miles; and it probably drains an area of 40,000 square miles. The most important towns on its banks are—Aranjuez, Toledo, Talavera, Almaraz, Alcantara, Santarem, and Lisbon.