606 



los del Rio Negro, and the Peak of Duida, the 

 granite is traversed by numerous veins of diffe- 

 rent ages (Vol. v, p. 401), spread over with 

 rock-cry stal, black tourmaline, and pyrites 

 (Vol. v, p. 229, 506). It appears that these 

 open veins become more common on the east of 

 the Peak of Duida, in the Sierra Pacaraina, above 

 all between Xurumu, and Rupunuri (tributary 

 streams of the Rio Branco, and the Essequibo), 

 where Hortsman the traveller, discovered in- 

 stead of diamonds * and emeralds, a mine, or 

 oven of rock-crystal (Vol. v, p. 792 ; Vol. vi, 

 p. 518). 



(i. Gneiss predominates along the Cordillera 

 of the shore of Venezuela with the appearances 

 of an independant formation in the northern 



nitic chain of the Encaramada (Vol. vi, p. 502), seem to de- 

 note the proximity of amphibolic or chloritic slate (hornblend 

 or chlorit schiefer) , either in layers in the granite, or super- 

 posed on that rock (Vol. v, p. 678). 



* These fables of diamonds are very ancient on the coast 

 of Paria. Petrus Martyr relates, that at the beginning of 

 the sixteenth century, a Spaniard, Andres Morales, bought 

 of a young Indian of the coast of Paria tc adamantem mire 

 pretiosum, duos infantis digiti articulos longum, magni auiem 

 pollicis articulum cequantem crassiludine, acutum utrobique et 

 costis 8 pulchre formatis constantem." This pretended adamas 

 juvenis pariensis resisted the lime. Petrus Martyr distin- 

 guishes it from topazes by adding, c< offenderunt et topazios 

 in littore,'' that is, on the coast of Paria, Saint Martha, and 

 Veragua. $ee Oceanica, Dec. iii, lib. iv, p, 53, 



/ 



