280 C. Lapworth. — Geology of Galashiels. 



the latter direction. The Thomilee slates seem to have been formed 

 in shallow water, and are covered with tracks of Annelides, are often 

 of a bright red or purple colour, show not the slightest trace of 

 calcareous matter, and contain exceedingly few graptolites. On the 

 other hand, the Grieston slates have generally a greyish blue 

 appearance, have few traces of Annelides, contain pockets of 

 calcareous matter, in certain beds are crowded with G-raptolites, and 

 are more than double the thickness of those of Thomilee. 



We have added nothing but Protovirgularia HarTcnessi tothe fauna 

 foimd at Thornilee by Professor Nicol. These beds are cut through 

 by a couple of igneous dykes, and have been much disturbed. They 

 can be traced across the country for many miles in a N.E. direction, 

 always associated with the intrusive dykes. 



In the G-rieston, in addition to the fossils mentioned by Nicol (G. 

 Sedgwichii, priodon, and Griestoniensis) , my friend, Mr. James 

 Wilson, detected Betiolites Geinitzianus (Barr), and I have now to 

 add G. colonus (Barr), the small variety of Diplograpsus of the 

 Buckholm beds, the peculiar sponge-like reticulated fossil of the 

 Abbotsford greywackes, associated with many others whose identity 

 I have not as yet sufficient evidence to determine. 



Of the beds that lie to the north of the Grieston slates I shall say 

 nothing at present, as they seem to be entirely absent from the Gala 

 district, and the Gala Group may provisionally be considered as 

 terminated by the Thornilee slates, which appear to form the centre 

 of a synclinal. Beyond them the beds to the north, as a rule, have a 

 southward dip, and the Moffat shales are no doubt brought up again, 

 as we have found pieces of black shale in the drift and water-laid 

 gravel of Gala, containing pristis, teretiusculus (His.), tamariscus — 

 all fossils of the Moffat shales. 



Fossils. — The fossils of the Gala Group are exceedingly rare, a careful 

 examination of every foot of the more shaly strata for a hundred yards 

 sometimes failing to reveal even the trace of an organism. Whenever 

 the almost universal argillaceous character of the shales is exchanged 

 for one slightly more arenaceous, then the fossils begin to appear, 

 and they are found in a thin sandy or micaceous layer of this kind 

 of a fraction of an inch in thickness, when they are entirely absent 

 from all the adjacent strata. Again, they are never wholly absent 

 from the thin seams of slightly sandy carbonaceous shale that are 

 more common towards the base of these deposits. In the finely- 

 levigated shales, if we except those of Buckholm, they are never 

 found. 



The whole formation is remarkably deficient in calcareous matter. 

 A few of the shales on the Gala Grit effervesce when treated with 

 acids, and there are a few limy pockets in the Grieston, but not a 

 yard of strata as yet exposed deserves the name of calcareous. 



The following table shows the range and distribution of the fossils 

 of the Gala Group, and I have inserted a couple of additional columns, 

 the first showing if the fossil be found in the Coniston Series ; the 

 second, if it be present, in the Moffat Group : — 



