Geological Society of London. 181 



The author then compared the Post-glacial with the Pre-glacial 

 Mammalia. The British species of the latter are : — 



Ursus arvernensis. 



spelceus ?. 



Sorex. 



My gale moschata. 

 Talpa europo&a. 

 Cervtis megaceros ? 



capreolus. 



elaphus. 



Sedgwickii. 



Ardeus. 



Bos primigenius. 

 Hippopotamus major. 

 JEquus fossilis. 

 Rhinoceros megarhinus. 



Mrmeus. 



Mephas antiquus. 



meridionalis. 



Arvicola amphibia. 

 Castor fiber. 

 Trogontherium Cuvieri. 



Of these 19 species inhabiting Britain before the deposition of the 

 Boulder-clay, 12 survived into Post-glacial times. 



Passing from Post-glacial to Prehistoric time, the Sheep, Goat, Bos 

 longifrons, and Dog make their appearance, while the great Pachy- 

 dermata, the Cave Mammals, and nearly all the northern forms dis- 

 appear. The characteristic Post-glacial Mammals were defined by 

 the author to be — • 



Palaeolithic man. Ovibos moschata. 



Oulo luscus. Rhinoceros tichorhinus. 



Ursus spelceus ?. Mephas primigenius. 



ferox. Lemmus. 



Felis leo. Spermophilus citillus, 



pardus. erythrogenoides. 



Hycena spelcea. 



The author finally discussed the question of the age of the Lower 

 Brick- earths of the Thames Yalley and Clacton, and indicated the 

 difficulty of proving, from Paleeontological evidence, whether they 

 are Pre- or Post-glacial. He supposed that during the Glacial sub- 

 mergence, the valley of the Lower Thames roughly marked the coast- 

 line of the icy sea, with a climate too cold to allow the continued re- 

 sidence of the Pre-glacial mammals, but which might still occasionally 

 be visited by their surviving descendants, the remains of which would 

 thus be mingled with those of Arctic immigrants. 



Discussion.- — The President suggested that a fourth period might he added to the 

 three adopted by the author, viz., ttie Glacial period, during which it would appear 

 from the paper that some animals may have lived in Britain. 



Mr. Busk thought that some of the animals of the Post-glacial period, such, for 

 instance, as the Hysena and Lion, were of southern, and not, like many of the others, 

 of northern and eastern origin. The Lynx also might not improbably be of African 

 descent. It was abundant in the bone breccia of Gibraltar, as was also the Cervus 

 elaphus. Mipptopoiamus^ Elephas antiquus, and possibly Rhinoceros, might also be 

 regarded as southern forms ; and it was worth consideration whether the fauna might 

 not be connected with the time when Southern Europe was joined on to Northern 

 Africa. 



Mr. Tate stated that at Carrickfergus there was a Forest-bed underlying Glacial 

 drift, from which possibly the Elephant remains found there had been derived. 



Mr. J. W. Flower objected to all the fossils attributed to the Post-glacial period 

 being regarded as synchronous, and to the cave- and river-deposits being classed 

 together. 



Mr. Evans hoped that at some time a chronological arrangement of British caves 

 might be proposed. He mentioned the discovery of a palaeolithic flint implement in a 

 brickfield at Highbury, and argued against the lower level deposits of the Thames 

 valley being regarded as more ancient than the higher. 



Mr. Topley called attention to the absence of river-gravels and caves in the Silurian 



