Dr Hibbert on the Discovery of the Fossil Elk. 25 



But as we recede from the sea, and approach towards the 

 range of hills which forms the southerly limits of the Curragh, 

 we find that the surface of the bank more or less gradually 

 slopes off, so as to form a depression or hollow of inconsider- 

 able depth, in which has formerly subsisted one or more in- 

 land lakes or marshes. Accordingly, the channels of several 

 small rivers, deriving their origin from lofty rocks of clay- 

 slate, may be detected, to which the ancient lakes of the Cur- 

 ragh have been indebted for their supply. These mountain- 

 streams have, in the course of ages, carried with them im- 

 mense quantities of the disintegrated materials of the hills 

 from which they have had their origin, and have deposited 

 them in the form of gravel, clay, or sand, by which means the 

 depression of the Curragh has been in some measure reduced. 

 Again, the lakes in their overflow have formed for themselves 

 various narrow channels or outlets, by which they have com- 

 municated with the ocean. These rivers have exerted a deep 

 cori'osive action on the loose materials of the diluvium ; and 

 while the lakes of the Curragh have become more shallow 

 from the filling up of their basins, a considerable drainage has 

 also conspired to prevent this low tract from being overflowed. 

 But to more particularly describe these effects would be fo- 

 reign to my present object. Suffice it to say, that the surface 

 of the diluvium has, from these causes, undergone very con- 

 siderable modifications. On the north-west of the Cur- 

 ragh a terrace of debris may be observed, such as is thrown up 

 by a river, when it forces its way through earthy or stony mate- 

 rials loosely accumulated. This terrace consists of alternating 

 layers of gravel, marl, and sand, and (if I do not mistake the 

 site, which has been pointed out by Mr Oswald) one or two 

 ribs of animals, said to be of the elk, which had probably 

 drifted thither from the neighbourhood, were, many years 

 ago, discovered imbedded in this mass. 



I shall now advert to the most frequent circumstance con- 

 nected with the discovery of the fossil elk in the Curragh, 

 namely, its inhumation in alluvial marl. But there are, in 

 this case, two varieties of this substance to be distin- 

 guished. The first is that which had once subsisted as diluvial 

 clay-marl, but either from being exposed to the action of 



