6 MEMOIRS OF THE CARNEGIE MUSEUM 



have to be constructed to protect the settled parts of the coast-lands from being 

 flooded by high tides. They form part of an alluvial belt which rises gradually 

 from the sea-level and extends inland for a distance varying from ten to forty 

 miles, and which is comiDosed of variously colored clays with intermediate layers 

 of sand and peat, the latter being locally known as pegass. 



"The margins of this formation along the sea and rivers are covered with a 

 dense growth, consisting principally of mangrove {Rhizophora mangle) and of 

 courida {Avicenna nitida), which form natural sea-defences, the former being found 

 along the western and the latter along the eastern parts. Behind this growth are 

 flat grassy savannahs [p. 10] interspersed with forest, consisting mostly of Aeta 

 and Trooli palms {Mauritia flexuosa and Manicaria saccifera), whilst in some parts 

 the land is covered with a dense jungle. It is on this belt that all the sugar estates 

 and bj^ far the greater part of the cultivated areas are situated. 



" The Sand and Clay Belt. — The alluvial belt is succeeded by a slightly elevated 

 and undulating belt composed of sandy and clayey sedimentary soils, derived 

 from the disintegration of the various country rocks in situ, and traversed in some 

 places by sand-dunes, which rise from fift}^ to about one hundred and eighty feet 

 above the sea-level. This second belt commences at the Waini River, in the north- 

 western district, and graduallj^ increases in width as it extends toward the eastern 

 boundary of the Courantj'ne, in the vicinity of which it attains its greatest depth 

 at about one hundred miles inland. Grass-covered downs occur on the banks of 

 the Berbice and Courantyne Rivers, but the greater part of this tract consists of 

 high forest, and along the river margins and in the valleys mora trees {Dimorph- 

 andra mora) grow plentifully. 



"The Hinterland. — Beyond these belts, southward, the country rises between 

 the river vaUeys, which are in many parts swampy, and as it approaches the 

 sources of the larger rivers attains a height of about nine hundred feet above the 

 sea-level at the source of the Takatu, the western boundary, and about four hundred 

 feet above the sea at the source of the Courantyne, the eastern boundary. This 

 more elevated portion occupies about eleven-twelfths of the area of the colony. 

 It is diversified by numerous low hiUs and valleys, and contains three principal 

 mountain ranges, several irregularly distributed smaller ranges, and in its southern 

 and eastern parts many scattered isolated mountains, none of the last mentioned 

 being more than fifteen hundred feet above sea-level. 



"The eastern portion is almost entirely forest-clad, yet the country on the 

 western side of the colony, between the Rupununi and Ireng Rivers and extending 

 southwards from the Pakaraima Mountains to the Kanuku Range consists of an 



