94 SPOLIA ZEYLANICA. 
A difference in size of “identical types ’ from above and 
below the surface is not enough to establish an essential 
difference in age when the specimens are separated by only 
a few inches of soil ; a consistent difference of type is what is 
wanted. I will not here enlarge on the question of surface 
and buried implements, though it is one of considerable 
interest. Nor will I deal further with the stone tools of the 
hills, for all else I can say under this head has been said by 
others before me, so I will pass on to speak of the prehistorie 
antiquities of the lowlands. 
TV.—THE STONE TOOLS OF THE LOWLANDS. 
The stone tools of the lowlands occur in detrital deposits 
or on the surface of such deposits, from which some of them 
are derived. These accumulations take the form of gravels 
terracing the river valleys and capping low hills composed of 
red earth which commonly overlies the gravels, of sand dunes, 
of the clays and loams of the rice flats, and the beds of modern 
streams. The features of these deposits will be described 
later. 
The tools discovered include the forms described as belong- 
ing to the Hill series, together with another, and, I venture 
to think, older, assemblage, in which the types missing from 
the upland series are present. 
Noticeable features of the lowland group, as a whole, are 
the prevalence therein of steep-sided scrapers or planes, the 
number of split and worked pebbles, the presence of domed, 
tortoise-like pieces, the size of the tools, and their composition. 
On the average the lowland artefacts are very much larger 
than those of the Hill series. Small types occur, and these 
are generally composed of quartz either of the milky or crystal 
variety, while the bigger forms, more characteristic of the 
group to which they belong, were commonly struck from 
chert. 
The chert varies in quality from an opaque splintery 
substance, little used by stone-age peoples, to a stone with a 
fine conchoidal fracture, closely resembling European flint, 
and often translucent in thin flakes. 
