Geological Society of London. 43 



The author further discussed the theories which account for their 

 presence : — 1. That the animals lived much further south, and were 

 carried down by rivers to where they now lie. 2. That they lived 

 on the spot. As there are physical difficulties in the way of the 

 transport theory, as the Mammoth was covered with dense hair, and 

 fed on plants growing on the spot, and as the remains are not 

 confined to the vicinity of rivers, it is probable that the second view 

 is the correct one. 



There are, however, some points connected with it requiring 

 further consideration. It being proved that the Mammoth only 

 required a temperate climate, it must not be hastily assumed that it 

 could endure that of Siberia. Where the Mammoths are now found 

 the ground at two or three feet below the surface is permanently 

 frozen all the year round, vegetation does not appear till June, the 

 summer is very short, the winter proportionately long, vegetation 

 poor and stanted, the temperature in January is as low as — 65° F., 

 and no tree will now grow in the greater part of North Siberia. 

 How then could Elephas primigenius and Rhinoceros tichorliinus 

 obtain food on such ground? The only alternative seems to be, 

 either to suppose a great migration N. and S., or a change of 

 climate. The author is of opinion that in Siberia such a migration 

 is not possible. It seems therefore more probable that the climate 

 of Siberia has become more severe. The plants found in the 

 fissures of the Ehinoceros-teeth are those now living in South 

 Siberia. The plant-remains associated with the Mammoth (not 

 floated from a distance, but of the locality) show the same thing, 

 larch, birch, and other trees of good size being found. Freshwater 

 and land shells are also found, not now living. Hence it seems 

 reasonable to conclude that the climate has become more severe, and 

 that of the north in the days of the Mammoth resembled that of 

 the south at the present time. The author then considered the 

 cause of the Mammoth's extinction. This he held to have been 

 sudden. The remains must have been preserved soon after death. 

 He therefore maintains that they were destroyed by a flood due to 

 some sudden convulsion which also changed the climate. 



3. " On the Association of Dwarf Crocodiles (Nannosuchvs and 

 Therio melius pusillus, e. g.) with the diminutive Mammals of the 

 Purbeck Series." By Prof. E. Owen, C.B., F.E.S., F.G.S. 



The author noticed an objection which had been raised to his 

 view of the origin of the differences between the Mesozoic and 

 Neozoic Crocodiles by the adaptation of the latter to the destruction 

 by drowning of large mammalia (Q. J. Gr. S. xxxiv. p. 422), namely 

 that mammals were coexistent with the Mesozoic forms, and re- 

 marked that from their small size they would hardly constitute a 

 suitable prey for the Crocodiles to which he then specially referred, 

 but would be more likely to perform the same part as the Ich- 

 neumons of the present day, which check the increase of Crocodiles 

 by destroying their eggs and newly hatched young. He stated, 

 however, that in some slabs of "feather-bed" marl which accom- 

 panied the Becklesian Purbeck Collection to the British Museum, 



