ON ITS EXTERIOR. VOLCANOES. 311 



remains of a former watery covering. At the limit of 

 perpetual snow, the Kio Tinajillas takes its rise, which 

 afterwards, under the name of the Rio de. Quixos, 

 becomes an affluent of the Maspa, the Napo and the 

 Amazons. Two narrow wall-like elevations, which in 

 my topographical sketch of Antisana I have marked as 

 " coulees de lave," and which the natives call Volcau de 

 la Hacienda ami Yana Volcan (Yana, in the Quech-hna 

 language, signifies black or brown), rim like bands from 

 the foot of the volcano to the snow-line on the south- 

 western and northern declivities, and extend, as it 

 appears to mo, with very moderate angles of inclination 

 in a X.E. and S.W. direction about 13,000 feet over the 

 plain. With a very small breadth, they are about 192 to 

 213 feet above the ground of the Llanos de la Hacienda 

 de Santa Lucia, and del Cuvillan. Their declivities are 

 everywhere very abrupt and steep, even at the extremi- 

 ties. They consist, in their present state, of scaly and, for 

 the most part, sharply angular fragments of a black ba- 

 saltic rqck, without olivine and hornblende, but contain- 

 ing a few small crystals of white felspar. The mass has 

 often a pitchlike lustre, and contains interspersed obsi- 

 dian, which may be still more distinctly recognised, and 

 in great abundance, at Cueva de Antisana, of which we 

 found the height 15,942 feet. It is not, properly 

 speaking, a cave, but only a sort of shelter formed by 

 masses of rock which have fallen against each other, 

 which is resorted to by the herdsmen who ascend 

 the mountain, and in which we took refuge during a 

 violent hail-storm. It is a little to the north of the 

 Yolcan de la Hacienda. In the two narro~\\^rocky ridges, 

 which have the appearance of cooled lava-streams, the 



