Vol. 70.] THE ANDES OF PERU AXD BOLIVIA. 53 



the Falkland Islands, and South Africa. 1 Such evidence favoured 

 the Lower Devonian age of the rocks described by the Author as 

 containing this organism, and thus confirmed the previous researches 

 of Dr. IJlrich on the geology of this part of South America." 



Mr. A. Beebt Thompson asked the Author whether, in his 

 examination of the Lake Titicaca area, he had discovered indications 

 of petroleum. Several years ago a prospecting party sank some 

 boreholes a few miles away from the north-western shore of the lake 

 near Pirin, and it was said that at depths up to 800 feet oil of a 

 specific gravity of "840 was struck. It was known that petroleum 

 occurred in the Tertiary -rocks of Northern Peru, and now im- 

 portant detailed geological studies were being made of a large 

 area on the eastern slopes of the Cordillera in the province of 

 Santa Cruz (Bolivia), where exudations of oil from beds of supposed 

 Jurassic and Cretaceous age had been long known. 



The Author, in reply, stated that the chief source of petroleum 

 was in the north of Peru ; possibly some of the coal-bearing shales 

 of the south might be oil-bearing, but he was not aware that they 

 were worked for this product. With regard to Dr. Evans's state- 

 ment that the Bolivian granite showed no pressure-phenomena, 

 he wished to point out that Sir Martin Conway had recorded 

 gneissose structure in the granite of Mount Illimani. In forming 

 an opinion as to the date of the intrusion, the possibility of 

 its Palaeozoic age merited further consideration, as the absence 

 of Upper Devonian and Lower Carboniferous deposits in the area 

 suggested a period of continental elevation at that time. In reply 

 to Dr. Yaughan, he mentioned that several authors had published 

 tables correlating the Devonian fossils of South America Avith those 

 of the United States, and, applying these tables to the fossils that 

 he had found near Coniri, it was clearly shown that the few forms 

 recorded were from a Lower Devonian horizon. In conclusion, 

 he wished to add that, owing to the kind hospitality of Mr. 

 Wynne-Edwards and his assistant engineers, the conditions of 

 travel over this part of the route had not been quite so arduous 

 as some of the previous speakers had suggested. In thanking the 

 Society for the kind reception given to his paper, he also wished to 

 express his deep sense of gratitude to Mr. Balston for enabling 

 him to undertake the work. 



1 See Appendix to Sir Martin Conway's ' Bolivian Andes ' 1901, p. 386. 



2 Nenes Jahrb. Beilage-Band viii (1892) p. 116. 



