420 Symonds — British Fossil Mammals. 



the phenomena that occurred during the Glacial epoch is the fact 

 of the submergence of a great portion of the land of Pre-glacial 

 Britain and Western Europe beneath the Glacial seas. The Forest- 

 bed of Cromer was submerged, and the Glacial Boulder-clay rest 

 above it; while certain old river deposits of the Thames Yalley 

 appear from the researches of Mr. Boyd Dawkins to belong to a 

 somewhat later period, with a climate comparatively temperate, but 

 colder than that of the Cromer Forest-bed (Quart. Journ. Geol. 

 Soc, vol. xxiii.). Dr. Falconer in 1857 had been struck with the 

 Pliocene assemblage of species in these Lower Brick-earths of the 

 Thames Valley, and had inferred that they were of an earlier age than 

 any part of the Till or Boulder-clay (Quart. Journ. Geol. Soc, vol. 

 xiv., p. 83). It appears that these Thames Brick-earths are 

 covered by a Glacial deposit of angular ice-borne debris, as is the 

 Forest-bed by Boulder-clay. The mammalian relics are very 

 abundant, and the assemblage of species found in the river 

 gravels which underlie the Glacial debris have led Mr. Boyd 

 Dawkins to draw some very important inferences and conclusions. 

 Three species of elephants having an unequal range in time and 

 space, and all extinct, have been found in these lower Brick-earth 

 deposits. The Elephas primigenius (the mammoth) occurs in the 

 Pre-glacial Forest-bed of Norfolk. This animal was well defended 

 during the intense cold of the Glacial period by his long wool and 

 hair, and its remains are most abundant in the Post-glacial strata of 

 Europe and in the frozen gravels of Siberia and Korth America. 

 Elephas antiquus lived in Pliocene times on the continent of 

 Europe, is found abundantly in the Forest-bed of Cromer, and 

 like the Mammoth, lived on to Post-glacial times, but not in such 

 abundance. It is as remarkable, says Mr. Dawkins, for its southern 

 range as the Mammoth is for its northern visitations. It appears 

 '^ to be a Pliocene species that lived in great numbers in Britain, 

 while the Pre-glacial deposits of the Norfolk shores were being 

 formed, that was gradually supplanted by the Mammoth {JE. primi- 

 genius), and was driven southward by the lowering of the tempera- 

 ture." Elephas prisms was a Pliocene species of Italy and Central 

 France, which lived on to the Forest of Cromer period, and the 

 later period of the Thames Brick-earths, but has not been found in 

 Post-glaical strata. Three species of rhinoceros are found in the 

 Brick-earths of the Thames valley but one (R. megarhinus), which 

 is a Pliocene animal, and is found in the Forest-bed, does not ascend 

 to the Post-glacial deposits, as do both B. tichorhinus and R. lepto- 

 rhinus, which were more adapted to bear severe cold. R. tichorhinus 

 was protected like the Mammoth by long wool and hair. The pre- 

 sence of Elephas prisons and Rhinoceros megarhinus, indicate, says 

 Mr. Dawkins, the affinity of the group of Mammalia from the Brick- 

 earths to those of the Pre-glacial Forest-bed, and to the continental 

 Pliocene strata ; but a still more important inference is derived 

 from the absence of that Arctic group of animals which marks the 

 drifts and gravels of Post-glacial times. If the climate of the 

 maximum of the Glacial epoch was intensely cold, so was the climate 



