220 Reviews —Prof. Hull’s Physical History of the British Isles. 
good reasons for believing that the North Atlantic Ocean, properly so 
called, did not exist until after the close of the Carboniferous period. 
The main object of his work is to show by means of coloured maps 
(of which there are no less than twenty-seven), the relative position 
of land and sea as they appeared at certain well-recognized epochs. In 
the case of each epoch represented, there are two maps, one displaying 
by different tints the area over which the formation is exposed and 
concealed, and the other the respective areas of land and water at the 
time when the formation was laid down. 
The first map deals with the Laurentian period, or with the Archean 
or Pre-Cambrian rocks, the only vestiges of which the author recognizes 
in the North of Scotland and Ireland. He thinks that a ‘‘ primeval 
Atlantis”? was probably the parent land for the strata of this age on 
either side of the Atlantic. Thence we pass to the Cambrian period 
(in which Murchison’s grouping is taken), and behold the whole’ of 
England and Wales under water, with an Archean ridge stretching 
from the North-west of Ireland through the Highlands of Scotland. 
In Lower Silurian times all the British Islands, with perhaps the 
exception of a portion of the Hebrides, are under water: land stands 
out to the west. Then we come to the Upper Silurian and Devono- 
Silurian periods, taken together, and we have on the maps representa- 
tions of the extent of these strata, and of the various areas of deposition. 
Here we see the Lakes Orcadie, Caledonia, the Welsh Lake, ete., so 
named by Dr. A. Geikie, in which the ‘‘ Lower Old Red Sandstone” 
was formed. The Lower and Middle Devonian periods are also repre- 
sented on another map. Then we come to the ‘‘Old Red Sandstone 
and Lower Carboniferous periods’? grouped together for convenience, 
although the author regards the [Upper] Old Red Sandstone as a 
member of the Upper Devonian. series, rather than of the Carboniferous. 
In dealing with the Lower Carboniferous rocks, the author points out 
that from the distribution of limestones and shales and the alternations 
of these beds, it is evident that over the central region of the British 
Islands, the sea waters of this period were clear, and almost free from 
sediment; on the other hand, both to the north and south of the 
central region, they were laden with impurities. From this he infers 
that the lands from which this sediment was derived must necessarily 
have lain in these directions, namely, to the north-west and south-west 
of the British Isles. Thus even then the Atlantic Ocean, as such, 
had no existence. At this time, and during the succeeding Upper 
Carboniferous (Coal-bearing) epoch, there was, however, a barrier of 
the older rocks stretching from North Wales through Charnwood Forest 
to the east of England. Of course it is problematical how far east- 
wards this barrier did extend, and whether it ran due east or north- 
east, or very little further east than the Charnwood area: but as it 
appears on the map it looks uncomfortable for those who advocate the 
possibility of Coal-measures occurring at a workable depth under the 
surface in Norfolk. The succeeding maps illustrate the physical geo- 
graphy of the Permian, Triassic, Jurassic, Cretaceous, Lower and 
Middle Tertiary, and Glacial Kpochs. The Pliocene beds seem alto- 
gether neglected, but the omission is unimportant. We are informed 
by the author that in the Triassic map there is an error in the position 
