60 Prof. C. Lapworth—Ballantrae Rocks of South Scotland. 
The rocks of the Lower or Moffat Terrane attain their maximum. 
development in the Ballantrae-Girvan district to the extreme north- 
west of the Uplands. In this district the terrane is made up of the 
three successive local rock-formations which have been termed by 
myself! (a) the Barr or Stinchar Series (of Bala-Llandeilo age), | 
(6) the Ardmillan Series (of Bala-Caradoc age), and (c) the New- 
land Series (Llandovery). Its strata are here very varied in litho- 
logical character, contain an abundant fauna of all the usual 
Lower Paleozoic life types, and have an aggregate thickness which 
has been estimated at about 4000 feet. Followed thence, however, 
as they reappear in the many antielinal forms of the Uplands 
towards the south-east, they diminish very rapidly in vertical extent, — 
until, when we reach the Moffat district (50 miles to the south-east- 
ward), the strata of the entire terrane are reduced to a collective 
thickness of 300 or 400 feet. In this district also they have lost 
their original varied lithological characters, and have dwindled 
down into a comparatively homogeneous mass of black, grey and 
white shales: while their diversified fauna has degenerated into one 
almost exclusively Graptolitic.? Nevertheless, in spite of the re- 
markable attenuation of the strata of the terrane, its three component 
formations are still recognizable as the three local divisions of the 
Moffat Series, (a) Glenkiln Shales, (b) Hurtfell Shales, and (e) Birk- 
hill Shales. Paleeontologically these answer broadly to the three 
Girvan divisions, the Graptolites characteristic of the lowest Moffat 
or Glenkiln Shales being equally characteristic of the lowest or 
Stinchar formation of Girvan: those Graptolites in the second or 
Hartfell division being found in the second or Ardmillan formation 
of Girvan: while those of the highest or Birkhill shales agree 
precisely with the forms characteristic of the third or Newland 
formation of Girvan. This parallelism is not only evident as respects 
each of the three successive subfaunas, but many of the subordinate 
zones in these widely separated districts admit of an equally satis- 
factory parallelism in sequenee and in lithology, as well as in 
characteristic fossils.? 
To the south-west of the Moffat district the rocks of the Moffat 
Terrane soon plunge below strata of more recent age, and are seen 
no more within the limits of the Scottish Uplands. They must, 
however, still retain their attenuated and deep-water character for 
many miles in their subterranean course in this direction; for 
when they re-emerge in the Lake district (as the Coniston Lime- 
stone Group and Skellgill Graptolitic Shales), their middle members 
(Coniston Limestone Series) have only gained a few hundreds of feet 
in collective extent, while the strata of their highest division (Birk- 
hill or Skellgill Shales) are practically unaltered in lithology, thick- 
ness, and in fossils.‘ 
Graduating upward conformably from the highest beds of the 
1 Lapworth, Girvan Succession, Q.J.G.S. 1882, pp. 5387-666. 
2 Ibid, Moftat Series, Q J.G.S. 1878, pp. 240-346. 
3 Compare Tables Q.J.G.S. 1882, p. 660, and 1878, p. 250. 
* Marr and Nicholson, Q.J.G.S. 1888, pp. 706-708. 
