? EQUUS ZEYLANICUS. 273 
The geological interpretation of the Wellawatta sections 
appears as follows :— 
On a pre-historic flat bordering the sea an indigenous 
horse met its death.* Subsequent slow depression of the land 
resulted in the burial of such organic remains as might be 
strewn upon the surface of the flat, under deposits akin to 
those upon which they were resting. The flat, which partly 
filled a large bay (see p. 269), was bounded on the west by a 
coral reef. As the land sank the reef grew, till the quiet 
conditions which allowed of coral growth and the accumulation 
of kadu-suli no longer obtained. Possibly an ancient reef or 
rock-bar out at sea, serving in times of greater elevation 
to protect the shore from the onslaught of the waves, 
was now too far submerged to funetion as a_ break- 
water. Whatever the cause may have been, conditions 
changed ; the coral reef was denuded, and fragments of the 
mass were strewn across the surface of the kadu-suli. The 
land continued to sink, and sand was deposited seawards of 
the reef, above it, and above the gray sandy clay. Then a 
period of elevation set in and continued till the top of the 
sand appeared above sea level. Some of the upper layers 
were afterwards consolidated by lime-charged waters, and 
partially, perhaps, by efflorescence from the coral below, 
slight depression again took place, and swamps (to which the 
vegetable earth and sand bears testimony) appeared along 
the coast. Depression then continued, and marine deposits 
crept further inland. While the hardened sandstone out at 
sea supported coral growth (see p. 267), at length the down- 
ward movement was complete and the land rose again in a 
slow discontinuous way, thus giving rise to shore lines C, B, 
and A. When the coast had extended to B, swamps appeared. 
along the plain, and were afterwards replaced by jungle. The 
present beach and blown sand are the youngest deposits in 
the series. In a sense the vegetable earth is their contem- 
porary ; it should be noted, however, that this bed has a 
double history, for, although organic matter accumulates 
part passu with the dunes, and has been accumulating since 
* Indigenous for reasons set forth under the heading of Palzeonto- 
logical Evidence. 
