12 Geology of llm Gold FieMh of British Gtdana. 



( )1: these rivers the Mazaruni has the most singular course. Rising 

 in the Merume Mountains about 2,400 feet above the sea-level it flows 

 southward for some distance, then curving round to the west it turns 

 in latitude 5*^ 34' north in a north-westerly and then northerly direction 

 to the Peimah Falls. In this part of its course many lofty falls occur 

 Thence following a south-easterly direction to the mouth oi the 

 Merume, it approaches to within twenty miles of its source, having 

 described roughly almost an oval. Continuing with a tortuous course 

 south-easterly to the Teboco Falls in north latitude 5° 45' 29", it turns 

 thence to the north-east and flows through comparatively level countiy 

 to join the Esse((uil)0. Below the Peimah Falls bars of rock cross the 

 river in many places, giving rise to numerous rapids and low cataracts. 

 Its most important and largest tributaries are the Puruni, Merume, 

 Kamarang, Kako and Kukui Rivers. 



The Cuyuni, which rises in Venezuelan territory, through which it 

 flows for a consideral)le distance, forms the Venezuelan boundary of 

 the colony from below the mouth of the Wenamu to that of the 

 Akarabisi, along both of which tributaries the Venezuelan boundary 

 extends as far as their sources. It has a generally westerly course as 

 far as Tinamu Cataract whence it turns towards the south-east and 

 follows this course until it joins the Mazaruni. It flows through a 

 hilly although a comparatively low part of the colony, but its cnurse is 

 nevertheless obstructed by many rapids and cataracts, which form 

 serious impediments to navigation. Of the comparatively few large 

 tributaries of the Cuyuni the following may be mentioned — the Oko, 

 Arimu, Kopang, Iroma, Akarabisi, Ekereku and Wenamu Rivers. 



The Potaro and Siparuni Rivers, and the tributary of the latter, the 

 Burro-burro, which falls into it about five miles above its mouth, take 

 their rise in the Pakaraima Mountains and flow thi-ough country covered 

 with high foi'est. Their courses are broken by many high waterfalls 

 and cataracts, the highest and most striking of these being the Kaieteur 

 situated on the Potaro River which has ah-eady been descx'ibed. 



The Rupununi River joins the Essequibo in 4° 2' 52" north 

 latitude, and gives access during the rainy seasons to the elevated 

 grass-clad plains or savannahs, on which at the present time a 

 large number of cattle are being raised. During the height of 

 the dry seasons the river becomes very shallow, its course being 

 impeded by many sandbanks and rapids, and during this time it 

 can only be ascended with great difliculty and much loss of time, 

 or sometimes not at all. Its many inlets and large lake-like ponds 

 on both banks form a feature common also to the upper parts of 

 the Berbice River. Its largest tributary is the Rewa or Illiwa, 

 which is itself joined by the Quitaro, and both flow through country 

 covered with high forests. 



The Courantyne River, which forms the eastern lioundary between 

 the colony and Dutch Guiana, rises in 1" 48' 30" north latitude, 

 a>)Out 140 miles to the east of the Essequibo River. The water- 

 shed from which it I'ises separates its head-waters from those of the 

 rivers flowing to the Amazon system, and is only about 400 feet 



