The Cordilleras of Ancuma and Moquehua, and the longitudinal valley, or rather the basin of Titicaca, which they inclose, take a direction north 42 degrees west. Further on, the two branches again unite in the group of the mountains of Cuzco, and thence their direction is north 80 degrees west. This group of which the table-land inclines to the north-east, forms a curve, nearly from east to west, so that the part of the Andes north of Castrovireyna is thrown back more than 242,000 toises westward. This singular geological phenomenon resembles the variation of dip of the veins, and especially of the two parts of the chain of the Pyrenees, parallel to each other, and linked by an almost rectangular elbow, 16,000 toises long, near the source of the Garonne;* (* Between the mountain of Tentenade and the Port d'Espot.); but in the Andes, the axes of the chain, south and north of the curve, do not preserve parallelism. On the north of Castrovireyna and Andahuaylas (latitude 14 degrees), the direction is north 22 degrees west, while south of 15 degrees, it is north 42 degrees west. The inflexions of the coast follow these changes. The shore separated from the Cordillera by a plain 15 leagues in breadth, stretches from Camapo to Arica, between 27 1/2 and 18 1/2 degrees latitude north 5 degrees east; from Arica to Pisco, between 18 1/2 and 14 degrees latitude at first north 42 degrees west, afterwards north 65 degrees west; and from Pisco to Truxillo, between 14 and 8 degrees of latitude north 27 degrees west. The parallelism between the coast and the Cordillera of the Andes is a phenomenon the more worthy of attention, as it occurs in several parts of the globe where the mountains do not in the same manner form the shore. After the great knot of mountains of Cuzco and Parinacochas, in 14 degrees south latitude, the Andes present a second bifurcation, on the east and west of the Rio Jauja, which throws itself into the Mantaro, a tributary stream of the Apurimac. The eastern chain stretches on the east of Huanta, the convent of Ocopa and Tarma; the western chain, on the west of Castrovireyna, Huancavelica, Huarocheri, and Yauli. The basin, or rather the lofty table-land which is inclosed by these chains, is nearly half the length of the basin of Chucuito or Titicaca. Two mountains covered with eternal snow, seen from the town of Lima, and which the inhabitants name Toldo de la Nieve, belong to the western chain, that of Huarocheri.