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THE DEVONIAN ROCKS OF ILFRACOMBE. 
B. —Middle Devonian, or Ilfracombe Group. 
Barren grey slates, calcareous slates, and limestone grits and 
conglomerates. At Torquay an abundance of fossils is to 
be found in the limestone, principally corals, whilst in the 
northern part of the county Brachiopoda and Lamelli- 
braucliiata are the principal fossils. 
A. —Lower Devonian, or Lynton Group. 
Slates somewhat schistose, with red micaceous sandstone, the 
base of which is not visible. In these rocks a single fish, 
Pteraspis ; corals ; Brachiopoda, one of which is common 
in the Silurian rocks, Atrypa reticularis , and Trilobites* 
have been found. 
A few words now upon the great difference between the rocks 
of the Old Red Sandstone and those of the Devonian. 
The rocks of the Old Red contain fossils which show that the 
waters in which they lived were lacustrine, whilst the fossils con¬ 
tained in the Devonian rocks clearly point to a marine origin. 
Thus it is clearly shown that the Old Red Sandstone is a lacustrine 
formation, whilst the Devonian is a marine one. 
The conditions under which the Devonian rocks were deposited 
appear to have been these :—The Silurian rocks were gradually 
depressed and submerged; then, great masses of sediment were 
deposited upon them, which contained more or less calcareous 
matter, and in some cases scarcely any. Upon these, in some 
cases, corals grew, hence the coral beds of South Devonshire ; here 
various Bivalves and Gasteropods lived and died. In other cases 
the mud deposited was free from calcareous matter, and hence we 
have beds of slate and grit. 
The beds in which I worked during my recent stay of three 
months at Ashford, two miles from Barnstaple, in the direction of 
Ilfracombe, were the Upper and Middle Beds, but chiefly the latter. 
However, as I was fortunate enough to obtain fossils from the 
Hangman Grits, I will commence with these. 
II.— Middle Devonian Beds. Hangman Grits. 
These Grits are well exposed in the cliffs of the Little Hangman 
Hill, which forms a bold headland near Combe Martin. But, as 
* All the Trilobites found by me are more like those of the Carboniferous 
rocks than those of South Devon. 
April, 1898. 
