Correspondence — Mr. J. Gunn. 95 



classification, as passage-beds between the Baggy or Marwood bed 

 and the Pickwell Down Sandstone ; though to do this they must be 

 transported bodily at least one mile to the south. I may also notice 

 the misapplication of the term Baggy and Marwood slates — this bed 

 consisting principally of sandstone ; the thin intercalated beds of 

 olive slates and shale being the exception. 



In the Morthoe group I am not aware of any " purplish " slates. 

 Their real colour is a silvery grey. The purplish slates included by 

 Professor Phillips in the then undivided Morthoe group lie above the 

 Pickwell Down Sandstone, and form the passage between it and the 

 Cucullma zone. 



The suggestion as to the Foreland Sandstone being Upper Silurian 

 must be taken for what it is worth ; as with a few most indefinite 

 traces, which may be attributed to organic remains, it is impossible 

 to fall back upon palasontological evidence. 



Another objection to Professor Hull's explanation of the North 

 Devon section is, that he seems to ignore altogether the existence of 

 Upper Devonian fossils. The Ilfracombe group with its limestones 

 undoubtedly belongs to Middle Devonian age, and if both the Pilton 

 beds and the Cucullcea zone are transferred to the Lower Carbon- 

 iferous, he leaves no fossiliferous bed whatsoever of Upper Devonian 

 age ; but has evidently trusted that " Drayton and Slade " might 

 serve to fill up the gap, or that an unconformity might exist at the 

 base of Pickwell Down to account for it. 



Pilton, Barnstaple, Dec. 16, 1878. Townshend M. Hall. 



MIOCENE FLORA IN AECTIC REGIONS. 



Sir, — Voluminous and elaborate writings have issued from the 

 press, in almost every possible form, to account for the existence of 

 a Miocene flora in Arctic regions, without, I need scarcely say, any 

 satisfactory result. I venture in a few lines to suggest an element of 

 change, or rather a new application of one, which seems to have 

 escaped notice. It consists in the transfer of water by the Gulf 

 Stream from Equatorial to Polar Eegions. This is incessantly in 

 progress, and it would be difficult to ascertain the immensity of the 

 volume of water which is thus transferred, simply through the 

 agency of the sun. It would be equally difficult to ascertain the 

 enormous quantity of ice which is amassed annually by the congela- 

 tion of this water. It is the fact of its being so warmed which leads 

 to its being conveyed nearer to the North Pole than it could be under 

 other known causes, but the point must be reached when its fluidity, 

 in great part at least, must cease. 



Now, it appears to me, that, owing to this cause, there must be such 

 an accumulation of ice as would tend, if the pressure were equably 

 circumpolar, to depress the Equator : and, if it were lateral, as 

 under circumstances it must be, to produce an obliquity of poles, in 

 proportion to the bulk of the ice and its nearness to the Pole. With 

 reference to this obliquity, I might merely add Q. E. D., and submit 

 the problem to the public in the naked simplicity of truth, reserving 

 to myself the privilege of defence or explanation as occasion may 



