Lapworth 8f Wilson — Silurian Rocks of Roxburgh ^ Selkirk. 457 



occurring in the flanks of Ernton Fell in Liddesdale, and, arguing 

 from lithological characters alone, considered that some of the beds 

 to the south of Hawick were of Upper Silurian age ; but in a section 

 exhibited by him at the meeting of the British Association at Belfast 

 in 1852, and afterwards published in Sir Eoderick Murchison's Siluria, 

 he relinquished this opinion, and held that the Southern beds were 

 of the age of those associated with the Moffat Anthracite. 



The Geological Survey of Scotland published maps and explana- 

 tions of much of the northern portion of the district. In Berwick- 

 shire, Graptolites priodon was discovered at Byrecleuch, in Headshaw 

 Burn black shale with Dip. pristis, and also on the sides of Browbeat 

 Eig, in Peeblesshire. No evidence was, however, obtained by which 

 the strata could be split up, and the whole of the Silurians mapped 

 were coloured in one uniform tint. 



This is the sum of what was known of the district before we 

 began our investigations, and that which is additional in this paper 

 is mainly the result of our own labours. 



In an able, and at that time exhaustive paper on the Silurians of 

 South Scotland, by Professor Geikie, published in the third volume 

 of the Transactions of the Geological Society of Glasgow, the fol- 

 lowing sub-divisions of the strata were recognized ; — 



1. The purple schists of Eskdale-muir. 



2. The thin bedded flags of Glenkiln, etc. 



3. The greywackes and shale of Moffat. 



4. The thick grits of the Broad Law and Innerleithen. 



5. The Wrae and Winkstone beds. 



6. The blue grits and shales bordering the great Carboniferous 

 basin. 



7. The Girvan beds. 



8. The upper Silurians of Kirkcudbright. 



Our divisions are in effect the same as those of his. Our plan, 

 however, has been to name the several groups of strata after the 

 towns near which they attain their greatest development, and thus 

 we have in our country : — 



1. The Hawick rocks. 



2. The Selkirk beds. 



3. The Moffat series. 



4. The Gala group. 



5. The Eiccarton beds. 



Nos. 1, 2, 3, answer to Professor Geikie's divisions 1, 2, and 3 

 respectively. The Gala group embraces his divisions Nos. 4, 5, 6, 

 and possibly also the greater part of No. 7, while the Eiccarton beds 

 are the exact equivalent of his No. 8. 



It is well known that these Silurian beds of South Scotland dip 

 away from an anticlinal line that runs in a N.E. direction from 

 Dumfries to Berwick, and that the rocks lie, as a whole, in an as- 

 cending order as we proceed in a N.E. or S.W. direction at right 

 angles to this line. 



Taking advantage of this fact, we will briefly describe the strata 



