583 



covered in the whole eastern part of South 

 America. The close connection observed in 

 the soil of Parapara, between greenstone, am- 

 phibolic serpentine, and amygdaloides contain- 

 ing crystals of pyroxene; the form of the Morros 

 of San Juan, which rise like cylinders above 

 the table-land ; the granular texture of their 

 limestone surrounded by trapean rocks, are ob- 

 jects worthy the attention of the geologist, who 

 has studied in the southern Tyrol, the effects 

 produced by the contact of poroxenic porphy- 

 rys *. 



The calcareous soil of the Cordillera of the 

 shore is most frequent, as we have already ob- 

 served, on the east of Cape Unare, in^ the 

 southern chain ; it extends to the gulph of 

 Paria, opposite the island of Trinidad, where 

 we find gypsum of Guire, containing sulphur. 

 I have been assured that in the northern chain 

 also, in the Montana de Paria, and near Caru- 

 pana, secondary calcareous formations are 

 found, and that they only begin to appear on 



* Leopold de Buck, Tableau geologique du Tyrol, p. 17. 

 I learn by very recent letters from M. Boussingault, that 

 these singular Morros de San Juan which furnish a lime- 

 stone with crystalline grains, and thermal springs, are hol- 

 low, and contain immense grottos filled with stalactites, 

 which appear to have been anciently inhabited by the na- 

 tives. 



