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.