depositions of the Old Red Sandstone of the British Isles. 363 



rence would be that of Lundy Island, Exmoor, and the Quan- 

 tocks, in West Somerset and North Devon, which ia there 

 superinduced above the Silurian or old red, and where that 

 old red or Silurian incontrovertibly supports it. The third 

 system would be the Ocrynian, which appears to have finally 

 superseded the old red sandstone altogether. The compa- 

 ratively thin red and grey sandstone band, which extends from 

 Torquay, by Plymouth Sound, to the southwest of Padstow, 

 and of which, interpolated beds are conveyed into the upper- 

 most terms of the killas, precisely the same as the older red 

 is conveyed through the Cambrian, may have been derived 

 from the same ancient sources which supplied the incalcu- 

 lably more abundant materials of the former. 



1 believe I am fortified in this view, by an adequate, if not 

 by a maximum, per-centage of organic remains, which cha- 

 racterize the great divisions. 



The countless and varied remains of fish which have been 

 found in Scotland, appear at present, nearly one and all, to be 

 peculiar to the older red of the first system. Other fossils 

 which have recently been discovered in Peeblesshire and Gal- 

 lowayshire, have been determined by Mr Salter to be lower 

 Silurian species. The whole of the older rocks of Scotland, 

 which pertain to the first system, I propose therefore to annex 

 to the Cambrian system. The old red of Herefordshire, Mon- 

 mouthshire, the Mendips, and Exmoor, is so essentially Silu- 

 rian, that it can with no propriety be separated from that sys- 

 tem, as my fossils and the successions will shew. The Ocry- 

 nian system will commence where the old red or Silurian ends, 

 and the mixed character of its fauna and its flora, consist- 

 ing of Silurian, Ocrynian, and mountain-limestone, will con- 

 stitute the links, and supply the enormous void which subsists 

 elsewhere between the Silurian or old red and the carboni- 

 ferous strata. 



It is proper I should here add, that the alarming and un- 

 toward little Orthides of either Gorran, or elsewhere in 

 Devon or Cornwall, never must be taken alone or apart from 

 their inseparable associates. Culled and garbled extracts 

 and isolated sentences without their context, whether selected 

 from the Cornish tables, or other leaves of the great stone 



