North-west of the plain of Sassari is the mountainous peninsula of. Nurra, which stretches out into the sea, terminating in three abrupt headlands : Cape Caccia to the south, above 500 feet high • Cape Argentaro to the west ; and Cape Falcon, the Gorditanum Promon torium of Ptolemy, to the north. A. narrow and shallow strait, lined with sharp rocks, runs between this cape and the island of Asinara, the ancient Herculie limb., a mountainous island of a long irregular shape, indented by several gulfs and coves, and having nearly 30 miles of coast-line to a comparatively small surface. It is inhabited by a few shepherds and farmers. The north and west coasts of Asinara are very steep, Mont Scommunica, the principal elevation, being 1500 feet above the sea. The whole peninsula of Nurra is covered with mountains, the northern parts of which consist of great masses of granite with schistose rocks, and the southern part is compact lime stone with gypsum and quartz. The principal summits in this range are from 1400 to 2000 feet high.
An ancient volcanic district extends along the centre of the island, beginning at Monastir, north of Cagliari, and running northward between Nurri and Sardara : it comprehends the towns of Ales, Mills, and San Lussurgiu, which last is built in the crater of an extinct volcano. It then extends to Bonorva and Queremula, on the border of the great northern plain of Giavesu, where a crater is clearly distin guishable, which from its unbroken conical shape and fine red ashes bears the appearance of comparatively recent action ; and the whole surrounding country consists of slaggy lava, rugged scoriae, obsidian, and indurated pozzolana, with large hills of porphyritic tufa towards Bonorva, lying over calcareous rocks. The volcanic beds extend farther north, through Codrongianus and Osilo in the billy region east of Sassari, where remains of craters occur, to Castel Sardo, on the northern coast, where they form abrupt cliffs 300 feet above the sea. The town-wall and most of the houses of Castel Sardo are built of lava. The river Coguinas forma on this side the geological boundary between the primitive formations of the eastern country, and the trap and volcanic) products to the westward. At Nurri, in the southern part of the island, on the borders of the eastern highlands overlooking the Campidano, or great plain of Cagliari, are two hills called Pizz' e Ogheddu' and Pizz' a Ogu Manna,' meaning peaks of the little and great eye, which appear to have been iguivomous mouths. A lava etream has run from them over a calcareous tract, which forms an elevated plain or table-land nearly 1600 feet above the sea, called Sa Giant a Serri, from the neighbouring village of Serri. This plain is covered with oak, ilex, and cork-trees, while its northern declivity contains rich restore. North-west of this plain is the Giant, or lava bed of Geetori, of similar formation, which has proceeded from a crater near the town of Ales : it is strewed with masses of obsidian and trachytia and cellular Lava, ao as to resemble a city in ruins. At Monastir, in the plain north of Cagliari, there is a distinct doable crater, now well wooded, and a bridge has been constructed there of fine red trap over a feeder of the Ulla.
The principal rivers of Sardinia are :-1. The nrsi, the Thymus of Ptolemy. which drains the central part of the island. It rises near Radom, on the west side of the °allure Mountains, flows first south and then south-west, along the base of the Goceano ridge, passes through the floe valley of Ottana, receiving several tributary streams from the mountains of Genargentu ; then flowing by Fortion gianus it enters the plain of Oristano, passing north of that town, below which it torna abruptly to the south, and enters the sea after a tortuous course of between 70 and SO miles. In very dry summers it
is fordable near its mouth, but in winter it contains a vast mass of water, and inundates considerable tracts. 2. Tho Coguinas, in the northern part of the island, rises in the volcanic region of Bonorva, flows northward through the plains of Giaveau and Ozieri, receives several streams from the highlands of Goceano and of Gallim, passes between Mount Sawn and the Limbers ridge, when it assumes the name of Rio di Netlike, and flowing through • romantio ravine below the cliffs of Castel Doria, enters a fino plain adjoining the sea. It forms a small lake near its month, • few miles east of Castel Sardo. The course of the Coguinas la between 50 and 60 miles, sod it is fordable near its mouth, except in rainy seasons. 3. The Flenteedoso, the &spree of Ptolemy, the principal stream of the eastern part of the island, rises in the mountains of Corno di Bne, and runs southward through a high valley between the ridge of Genargentu on the west and the Ogliastra Mountains to the east, pawing through many solitary glens. It then turns eastward between the mountains of Sarrabus on one aide and the hills of Parte 011a, which divide it from the Campi dano, or plain of Cagliari, and afterwards winding through the fertile grounds of Villa l'nzzu, San Vito, and Murevera, enters the sea between two low rocky points on which stand the towers of Nalinas and Corallo, after a course of between 50 and 60 miles. As it runs between two mountain ridges, the basin of the Flumendoso is very narrow; in the winter it is swelled with the drainage of the Borman& ing mountain region, and it then assumes a very imposing appear epee. 4. The Monne, or Gila, rises in a fountain in the tableland of Sarcidann on the south slope of the Genargentu ridge, and, flowing southward through the plain of the Campidano, Is joined by the Calarita from the mountains of Gergei on the east, and the Sizerris, which comes near Iglesias', from the west. The united stream enters the Lake of Cagliari, which lice west of that city, and Is 6 or 7 miles long by 3 or I miles broad, and communicates with the sea by seven cuts through a narrow strip of sand. This lake is navigated by flat bottomed boats, and contains abitodance of cede, mullets, and other fishes ; it II also frequented by flamingoes and pelicans in the winter. Between the lower course of the Flumendoso and Cape Carbooara Is • remarkable seven-peakal ridge (2310 feet high), called Sotto Fratelli (Seven Brothers), which fills up the south-eastern angle of the island. Besides these four rivers there are many smaller streams, such as the Tarritasso, which (Iowa through the plain of Sawari, and is crossed near its mouth by a substantial Roman bridge in excellent preserva Coo ; the Tosino, or River of Boss, on the western coast ; and the Cedrino, or River of Orosel, which is navigable by boats for about a mile and a quarter inland on the eastern coast ; it is an abundant and impetuous stream from its source, which is on the eastern slope of the Barbargie Mountains.