30 F. W. Harmer — The Coralline Crag MolJuscan Fauna. 



facies to the fauna of the Coralline Crag. At the present day 

 this genus undoubtedly is characteristic of Northern latitudes, but 

 it is not confined to them. In the Eocene period, as Mr. AVood 

 points out, four species of Astarte lived in these latitudes, in asso- 

 ciation with animals and plants of a tropical character. The Astartes 

 of the Coralline Crag are all extinct, except two, which are Mediter- 

 ranean species; and their occurrence, therefore, does not, I think, 

 present any insuperable difficulty in the way of our accepting the 

 strongly preponderating evidence that the climate of the period in 

 question was considerably warmer than that of the present day. 



Summary of the Abundant and Characteristic Species of Mollusca 

 occurring in the coralline crag. 1 



Not known as living (37 per cent.) 82 



Living in distant seas — Pacific 3 



,, ,, Atlantic 1 



,, ,, "West Indian 1 



,, ,, South African 1 



,, ,, North American 1 



7 



Living in the Mediterranean 119 



Not living in Mediterranean, hut in "West European area 1 2 



131 



Not known to range to the south of British seas ... 1 



221 



Species of European Mollusca abundant in Coralline Crag. 



Southern and not British (26 per cent.) 35 



British (rare) and Southern 9 



(33 per cent.) — 44 



British (characteristic) and Southern 87 



British and not Southern 1 



132 



Professor Prestwich, it is true, does not admit this view of the 

 case, and claims that ice action had come into existence even at 

 the commencement of the deposition of the Coralline Crag, resting 

 his opinion on the fact that a water-worn block of porphyry was 

 found in the basement bed at Sutton, which he considers must have 

 been transported, either from Scandinavia or the Ardennes, by 

 floating ice. 2 I differ with considerable reluctance from so eminent 

 an authority, but I cannot help feeling that the evidence of this 

 one block is insufficient to support the theory built upon it. No ice 

 reaches our shores at the present day either from Norway or 

 Belgium, and the winter temperature of Northern Europe would 

 have to fall considerably before this could happen. The almost 

 entire absence of recent Northern shells from the Coralline Crag, 

 moreover, seems to imply either that the sea of that period was not 

 open to the north, or that the temperature of the seas of Scandinavia 

 were affected, as they are now, but to a greater extent, by the 

 Gulf Stream ; while as to Belgium, I am not aware that similar 

 ice-borne debris occurs in the Crag beds of that country, nor are 

 such boulders found, in our own Eed Crag, the climate of which 



1 The figures now given are slightly different to those originally stated, hut the 

 conclusions to be drawn from them are not affected by the alteration. 



2 Q.J.G.S., vol. xxvii, p. 134 (1871). 



