Antisana, a volcanic mountain of Ecuador, in the eastern Cordillera, 35 rn. S. E. of Quito, according to Humboldt, 19,148 ft. high; according to Wisse, 19,279. An eruption in 1590 is recorded; and Humboldt saw smoke issuing from several openings in 1802. Four immense lava streams descend from the snowy summit, one of which, the Volcan de Ansango, is 10 m. long and 500 ft. deep. The lava is mainly a black, cellular, trachytic porphyry. But the volcano is now dormant, if not extinct. On its side is Lake Mica, near which is the celebrated Hacienda, one of the highest habitations in the world and the centre of an extensive corral. Humboldt made its altitude 13,465 feet; Bous-singault, 13,356; Orton, 13,300.