206 ME. T. T. NEWTON ON THE VERTEBRATE [May 1 894, 



of which there is a stream, and the superficial area of the pro- 

 montory is too small for the accumulation of water in sufficient 

 quantity to carry in the larger specimens. Besides this, the 

 fissure is open at one end to the valley, and in this condition could 

 scarcely be filled with the deposit nearly to the top as it now is. 

 If, on the other hand, it is contended that the filling of the fissure 

 took place before the excavation of this valley, and consequently 

 before the formation of the system of valleys of which this is only 

 a part, it will be necessary to date back the formation of this 

 deposit so far as practically to concede its Pleistocene age. 



It seems possible that the fissure might have been partly filled in 

 Pleistocene times, and that the recent species found their way 

 in at a later date. If this were so, then the Pleistocene species 

 should be found at the bottom and lower parts, and the living 

 species at the top and higher parts ; but such is not the case. When 

 first Mr. Abbott began collecting these remains, it was only the 

 upper part of the fissure which was accessible, and the specimens 

 found were carefully kept by themselves ; afterwards, at about 

 halfway down, some Rhinoceros teeth were obtained, and subse- 

 quently other specimens were found at the lower part of the fissure. 

 A list of the species from both parts was kept, but it soon became 

 evident that the upper and lower parts yielded the same species. 

 The living species occurred at the bottom as well as at the top, 

 while the Arctic lemmings and northern voles were found near the 

 top as well as in the lower parts. It is tolerably certain, there- 

 fore, that the deposit is of about the same age throughout. The 

 possibility that in recent times the fox, badger, mole, and rabbit 

 may have burrowed into the accumulated earth, and have left their 

 remains in the burrows, to be mixed with the earlier forms, is a 

 supposition that has been duly considered. In so far as the rabbit 

 is concerned, this is probably correct, for the remains are not satis- 

 factory and the species is not certainly known in Britain as a 

 Pleistocene form. Some of the mole- and fox-remains might in 

 like manner have found their way into the deposit, and the birds 

 might have been carried in by the foxes. But if this view be 

 accepted, it practically acknowledges the Pleistocene age of the 

 mass of the deposit. There is, however, another standpoint from 

 which to view, the remains of the still living species. If we except 

 the smaller birds, very few of which have been recognized in 

 Pleistocene beds, nearly the whole of the remaining species in the 

 foregoing list have been recorded from Cave-earth, or other Pleisto- 

 cene deposits, in various parts of Britain, and several of the species 

 extend back in time as far as the Norfolk Forest Bed. 



Seeing, then, that there is in this fissure a fair number of the 

 characteristic Pleistocene species (2 forms quite extinct, and 11 

 extinct in Britain though living elsewhere) mixed with living- 

 species which are known to have lived in Pleistocene times, there 

 seems no reason for doubting the Pleistocene age of these represen- 

 tatives of living species ; and it becomes highly probable that to 

 the same period belong those other living species which are mixed 



