614 



is not linked below by layers containing some 

 vestiges of monocotyledon plants. 



The small thonschiefer bed of Malpasso (in 

 the southern chain of the Cordillera of the 

 shore), is separated from micaslate-gneiss by 

 a co-ordinate formation of serpentine and dio- 

 rite. It is divided into two shelves, of which 

 the upper presents green steatitous slate, mixed 

 with amphibol ; and the lower, dark-blue slate, 

 extremely fissile, and traversed by numerous 

 veins of quartz (Vol. iv, p. 281). I could dis- 

 cover no fragmentary layer (grauwache), nor Me- 

 selschiefer, nor chiastolithe. The MeselscMefer 

 belongs in those countries to a limestone for- 

 mation, which we shall soon describe; I h#ve 

 seen fine specimens of the chiastolithe (macle) 

 which the Indians wore as amulets, and which 

 came from the Sierra Nevada de Merida. This 

 substance is probably found in transition-slate, 

 for MM. Rivero and Boussingault observed 

 rocks of clay-slate at the height of 2120 toises, 

 in the Paramo of Mucuchies, in going from 

 Truxillo to Merida*, 



* In Galicia, in Spain, I saw the thonschiefer alternate, 

 which contains chiastholite with grauwacke ; but the chias- 

 tholite belongs indubitably also to rocks which all geog- 

 nosts have hitherto named primitive rocks, to mica-schistes 

 intercalated like layers in the granite, and to a soil of inde- 

 pendent micaslate (Charpentier, p. 143, 193). 



