whole southern boundary of New Mexico, which runs north of the town of El Paso, to its western termination;—thence northward, along the western line of New Mexico, until it intersects the first branch of the river Gila, or, if it does not intersect any branch of that river, then to the point on the said line nearest to such branch, and then in a direct line to the same;—thence down the middle of the said branch and of said river, until it empties into the Rio Colorado;—thence across the Rio Colorado, following the division line between Upper and Lower California, to the Pacific Ocean.

It will be perceived by inspecting the map that this new boundary cuts off a large portion of northern Mexico, and gives us the valuable territories of New Mexico and Upper California, together with an undisputed right to the enjoyment of Texas, which had previously been united to the North American confederacy by international contract, after the independence of Texas had been recognized by foreign nations and maintained by its own people.

The states of the Mexican Republic and its territories are, consequently, under the existing constitution, the following:

Rivers and Lakes of Mexico.

I. On the Eastern Coasts.

1st. The Rio Grande del Norte, or Rio Bravo, which is the largest of all Mexican streams, and rises, in about 40¹/₂° north latitude, and 100° west longitude, from Paris, in the lofty sierras which are a continuation of the gigantic chain that forms the spine of our continent. It pursues a southeasterly direction towards the Gulf of Mexico, and traverses a distance of nearly eighteen hundred miles.

2d. The Rio del Tigre, rises in the state of Coahuila, and passes, in a southward and easterly direction, through the states of New Leon and Tamaulipas, and finally, after traversing about three hundred miles, debouches in the Gulf of Mexico.

3d. The Rio de Borbon, or Rio Blanco. The sources of this stream are in New Leon, whence it runs towards the east, and, crossing the state of Tamaulipas, falls in the Laguna Madre.

4th. The Rio de Santander, rises in the state of Zacatecas, crosses the state of San Luis Potosi, passes by Tamaulipas, winds to the north, and falls, near the bar of Santander, into the Gulf.

5th. The Rio de Tampico, is formed by the union of the rivers Panuco and Tula. The upper source of the Panuco is in the neighborhood of the city of San Luis Potosi, the capital of the state of that name. Near half a league north north-east of this city, in the valley de la Pila, rises a spring which is protected by a basin of fine masonry, and conveyed by an aqueduct to town. Several other streams, coming from the south-west, unite with this source and form the Panuco. West of the first of these streams, swells up the mountainous ridge which divides the waters of Mexico between the Pacific and the Atlantic. The Panuco courses eastwardly,—and, passing rapidly through the Laguna Chairél, unites with the Tula. This latter stream mingles the waters of the rivulets Tepexi, Tequisquiac, and Tlantla, in the northern part of the state of Mexico; and receiving, by the canal of Huehuetoca, the water of the Rio Quautitlan, it winds onward through the valley of Tula, and near the limits of the states of Queretaro and Vera Cruz, until it joins the Panuco. These united rivers receive in the state of Tamaulipas, the name of the Rio de Tampico, which debouches, finally, in the Gulf of Mexico.

6th. The Rio Blanco rises in the state of Vera Cruz, near Aculzingo, at the foot of Citlaltepetl, or the mountain of Orizaba. It courses onward through a varying and rough channel among the mountains and plains, until it is lost in the lagunes near Alvarado.

7th. The Rio de San Juan. The sources of this river lie partly in the metallic mountains of Ixtlan, in the state of Oajaca, and partly in the neighborhood of Tehuacan de las Granadas. Many large, but wild streams, spring up in these mountain regions, and form the broad but shallow Rio Grande de Quiotepec. This river, after winding through the valley of Cuicatlan, receives, from the south, the large stream of Las Vueltas; and all these unite to form the Rio de San Juan, which pursues its eastern course until it approaches the coast near Alvarado, when it divides into two arms. One of these, named Tecomate, joining the Cosomaloapan and Paso, form the large lagunes of Tequiapa and Embarcadéro,—whilst the other arm, by a different course, also debouches in the same lagunes.

8th. The Rio de Guasacualco, rises at about 16° 58´ of north latitude, and 96° 19´ west longitude, from Paris, in the mountains of Tarifa, and pours onward towards the east, receiving accessions from a great number of small mountain streams and rivulets, until it falls into the Gulf of Mexico.

9th. The Rio de Tabasco, or Rio de Grijalva, or Rio Guichula, rises in the mountains of Cuchumatlanes towards the centre of Guatemala, and falls into the gulf at the port of Tabasco.

10th. The Rio de Usumasinta, rises also in Guatemala, and debouches in the Laguna de Terminos.

II. Small Eastern Coast Streams.

Many of these streams are, in fact, not entitled to the name of