282 C. Lapworth. — Geology of Galashiels. 



Of the various species named in tlie above list, Crossopodia Scotica, 

 Nereites Cambrensis, and that peculiar fossil Trichoides amhiguus, 

 have all been discovered in the Moffat country, in the quarry at 

 Hunterbeck • but, if Professor Harkness be correct in ascribing the 

 repetition of the Anthracitic shales to great parallel faults, these beds 

 may form part of the Gala series. 



The presence of Peltoearis ajptychoides and Discinocaris Browniana 

 indicate a proximity to the Moffat beds, but the evidence they afford 

 is more than counterbalanced by the presence of Ceratiocaris and 

 other allied Caradoc forms. 



Protovirgularia HarJcnessi and the Eurypterus are peculiar to the 

 Gala Group, and of no value in fixing its age, and thus we are driven 

 to depend upon the well-marked set of Graptolitidge for more certain 

 evidence. Fortunately, this is very decided, and, taking this as our 

 main guide, we notice the following facts : — 



1st. That there are two distinct and characteristic faunas in the 

 district, the one peculiar to the Black Shale, the other to the Gala 

 Group. 



Of the thirteen fossils tabled above as being found in the shales, 

 every one belong to the Moffat beds, and three are peculiar to that 

 formation (C. capillaris, B. maximus, and S, micula), having never 

 yet been found in the Caradoc. 



Above the dark shales all are Coniston Graptolites, and at least 

 four have never yet been found below the equivalent of the Bala 

 Limestone. 



The foliaeeous species of Graptolites constitute more than a third 

 of the fauna of the shales. Above the Anthracitic schists, on the 

 contrary (if we except the small form of the Buckholm beds), all 

 are mono-prionidian. This is, I know, but negative evidence ; but 

 the same seems to obtain in Cumberland also, where none of the 

 Diplograpsi survive even into the higher Coniston flags. This 

 phenomenon may, of course, be due to conditions of sea-bottom, and 

 can at furthest be merely local, as both forms of the Graptolites expire 

 together in Barrande's tipper Silurian ; yet the circumstance is very 

 noteworthy, and may serve here or in England to distinguish between 

 the higher and lower beds of the series. 



2nd. Tlie upper fauna is pre-eminently of the Coniston or Bala type. 



In the Abbotsford Flag, for the first time in the age of the 

 Lower Silurian of Scotland, do we meet with G. pr-iodon, a fossil that 

 has never yet been detected below the Caradoc, proving at once that 

 we are in a superior division to that of the Moffat series. G. colonus, 

 a Lower Ludlow fossil in Siluria, soon becomes associated with it, 

 and the two run together to the summit of the series, as in the 

 Coniston Group, proving the unity of the whole deposit. To these 

 that pretty little fossil, G. turricidatus, is soon added. This has only 

 been found in Britain in the Coniston Flag, and is one of the many 

 forms added to the British Graptolitidce by Dr. Nicholson ; and, lastly, 

 we have BetioUtes Geinitzianus, an Upper Silurian fossil of the 

 Pentlands and Siluria, till the researches of Professor Harkness and 

 Dr. Nicholson placed the Cumberland beds in the Upper Caradoc. 



