C. Lapworth. — Geology of Galashiels. 283 



Thus we have four forms in the Gala Group which have never 

 been detected below the Bala beds, and are peculiar to the Caradoc, 

 or found only in that or higher deposits. 



Professor Sedgwick and the Geological Survey of England place 

 the Coniston beds in the Upper Silurian ; but, even should this turn 

 out to be the correct theory, it will merely clench the evidence before 

 adduced to show that the Gala beds must be high in the Lower 

 Silurian, and will strengthen the probability of their forming part of 

 the Caradoc. 



A careful comparison of the list of Moffat fossils given by Mr. 

 Hopkinson in the Geological Magazine for Feb., 1870, shows the 

 clear separation of the Moffat and Gala Series. Of the 41 Graptolites 

 in Hopkinson's list, 8 (i.e., Didymograpsi, Cladograpsi, D. pristini- 

 formis, mucronatus, and C. bicornis) are peculiar Llandeilo forms, 

 while only 16 of the Graptolites of Moffat are found in the Coniston 

 Group — or, in other words, one-third of the Graptolites of Moffat 

 found elsewhere in Britain are peculiar to the Llandeilo. On the 

 other hand, of the 12 known species of Graptolites given above as 

 being found in the Gala Group, 4 only are common to the Gala and 

 Moffat beds, the whole 12 have been found in the Coniston series, 

 and 4 have never been found below the Caradoc, while every one is 

 an Upper Silurian form in Bohemia. 



From the description of the rocks given in the foregoing pages, 

 and the list of fossils given above, it is plain that the whole set of 

 beds considered as the Gala Group belong to one and the same 

 formation, even if they be properly separable into subordinate 

 divisions, as they seem to be in this district. The constant repetition 

 of greywackes and shales, with alternating bands of flag or tiley 

 strata, all bearing a remarkable similarity, renders it next to impos- 

 sible to distinguish the position of any given bed here ; and where 

 the conditions of the sea bottom were different, as they were neces- 

 sarily in an increasing ratio as we depart from the typical area, the 

 deposits must have taken place under altogether different conditions, 

 and the chances are that these divisions will be no longer recognizable 

 lithologically, and we shall be driven to depend upon fossil evidence 

 alone. But here the difficulty is increased, and the very facts that 

 prove so conclusively the unity of the formation, militate against our 

 attempt to distinguish its different beds. From the Abbotsford 

 Greywackes to the summit of the Grieston Slates not a single new 

 Graptolite seems to make its appearance, and hardly a fossil appears 

 to have died out, though a change in the character of the sea bottom 

 has introduced a swarm of Annelides and those fossils found in the 

 mud of shallow seas. Hence, in effect, the Gala Group may collec- 

 tively be considered as a thick and almost inseparable series of 

 greywackes and shales, superior to the Moffat Series, and of Caradoc 

 age. The Gala Group is plainly recognizable from the description 

 given by Mr. Geikie (Mem. Geol. Surv., sheet 34), as being present 

 in the troughs of the strata along the Berwickshire coast, where it 

 has been rightly considered by him as of Caradoc age. It is seen 

 again along the valley of the Dye water. (Mem. Geol. Surv., sheet 



