ALTERATION OF THE WATEB-LEVEL. 297 



the eastern bank, the Sanariapo, and on the western, the 

 Cameji and the Toparo. Opposite the village of Maypures, 

 the mountains fall back in an arch, and, like a rocky coast, 

 form a gulf open to the south-east. The irruption of the 

 river is effected between the mouths of the Toparo and the 

 Sanariapo, at the western extremity of this majestic amphi 

 theatre. 



The waters of the Orinoco now roll at the foot of the 

 eastern chain of the mountains, and have receded from the 

 west, where, in a deep valley, the ancient shore is easily 

 recognized. A savannah, scarcely raised thirty feet above 

 the mean level of the river, extends from this valley as far 

 as the cataracts. There the small church of Maypures has 

 been constructed. It is built of trunks of palm-trees, and 

 is surrounded by seven or eight huts. The dry valley, which 

 runs in a straight line from south to north, from the Cameji 

 to the Toparo, is filled with granitic and solitary mounds, 

 all resembling those found in the shape of islands and shoals 

 in the present bed of the river. I was struck with this 

 analogy of form, on comparing the rocks of Keri and Oco, 

 situated in the deserted bed of the river, west of Maypures, 

 with the islets of Ouivitari and Caminitamini, which rise 

 like old castles amid the cataracts to the east of the mission. 

 The geological aspect of these scenes, the insular form of 

 the elevations farthest from the present shore of the Orinoco, 

 the cavities which the waves appear to have hollowed in the 

 rock Oco, and which are precisely on the same level (twenty- 

 five or thirty toises high) as the excavations perceived oppo- 

 site to them in the isle of Ouivitari ; all these appearances 

 prove that the whole of this bay, now dry, was formerly 

 covered by water. Those waters probably formed a lake, 

 the northern dike preventing their running out : but, when 

 this dike was broken down, the savannah that surrounds 

 the mission appeared at first like a very low island, bounded 

 by two arms of the same river. It may be supposed that 

 the Orinoco continued for some time to fill the ravine, which 

 we shall call the valley of Keri, because it contains the rock 

 of that name ; and that the waters retired wholly toward 

 tho eastern chain, leaving dry the western arm of the river, 

 only as they gradually diminished. Coloured stripes, which 

 no doubt owe their black tint to the oxides of iron and 



