240 



the Great Canary, Fortaventura, and Lanze- 

 rota *. I was not able to determine the nature 

 of this secondary rock ; but it appears certain, 

 that the island of TenerifFe is altogether desti- 

 tute of it ; and that among it's alluvial lands it 

 exhibits only clayey calcareous tufa, but which 

 alternates with volcanic breccias, and which, 

 according to Mr. Vieyra contains near the 

 village of La Rambla, at Calderas, and near 

 Candelaria, plants, imprints of fishes, buccinites, 

 and other fossil marine productions. Mr. Cor- 

 dier has brought away some of this tufa, which 

 resembles that in the environs of Naples and 

 Rome, and contains fragments of reeds. At 

 the Salvages, which La Perouse took at a dis- 

 tance for a mass of scoriae, even fibrous gypsum 

 is found. 



I had seen, while herbalizing between the port 

 of Orotava and the garden of La Paz, heaps of 

 grayish calcareous stones, of an imperfect con- 

 choidal fracture, and analogous to that of 

 Mount Jura and the Apennines. I was inform- 



* At Lanzerota calcareous stone is burned to lime with a 

 fire made of the alhulaga, a new species of thorny and arbo- 

 rescent sonchus. 



t Noticias historicas, t. i, p. 35. The Isle of France, 

 which rises in the form of a pyramid, and in the disposition 

 of it's volcanic hills has many points of resemblance with Te- 

 nerifFe, has a Neptunian plain in the quartier des Pample- 

 mousses. The calcareous stone there is filled with madre- 

 pores. Bory de St. Vincent, t. i, p. 207. 



