Prof. O. Lapworth—Ballantrae Rocks of South Scotland. 68 
reality the locus of a complex anticlinal form, whose component 
simple folds have been crushed together, overthrust, and irregularly 
denuded. As we pass from the Moffat area to the north-eastward, 
we find that each of these compound anticlinals increases in length, 
depth, and systematic importance. In the anticlinal forms of the 
first band (Moffat-Melrose) the exposures of the strata of the Moffat 
rocks appear as narrow inliers in the locally ended Gala terrane, — 
and are at the most a score or two of yards in width; while the 
total thickness of the pre-Gala rocks exposed (Birkhill to Glenkiln) 
is only from 300 to 400 feet. In the anticlinal forms of the second 
band (Lead Hills—Moorfoot) the exposure of the pre-Gala rocks are 
often more than a mile in diameter; and the strata of the locally 
thick Moffat Series are occasionally laid bare to a depth of at 
least two thousand feet, down to the calcareous strata at their base 
(Duntercleuch and Wrae Hill). Finally, in the most westerly 
anticlinal forms (those of Ballantrae and Girvan) the exposures of 
the pre-Gala rocks are four or five miles across; and, as we have 
seen, not only is the locally massive Moffat series exposed from 
summit to base (4000 feet), but even the underlying Ballantrae 
or Arenig rocks are laid bare, as far down as the horizon of the 
Skiddaw Slates. 
In the complex synclinal zones, between these complex anticlinal 
zones, the rocks of the Gala terrane form broader parallel bands 
sweeping longitudinally through the Uplands from sea to sea. The 
widest bands are those ranging along the exocline (Hawick line) 
already described, and those of Gala, Broadlaw, and Queensberry, 
These bands, however, are all united into a more or less continuous 
sheet, the Moffat exposures which locally divide them being usually 
of small longitudinal extent. The Gala beds, on the other hand, 
which occur north of the main Lead Hills anticlinal (endocline), as 
at N.W. Peebles, L. Doon, Girvan, ete., are usually disconnected, 
narrower, and of minor importance. 
The component formations of the underlying Moffat terrane are 
frequently well exhibited along the eroded crest of the intermediate 
anticlinal bands between the more or less continuous sheets of Gala 
rocks, and their gradual change in thickness, lithology, and paleon- 
tology can be followed, stage by stage, as we pass from place to 
place, and from fold to fold. 
Commencing with the most southerly, or Moffat-Melrose band, 
we find that in the typical area of the Moffat district we have 
merely the three Graptolitic zones of the Glenkiln, Hartfell and 
Birkhill, forming a comparatively homogeneous mass of grey and 
black shales and mudstones. Followed, however, even along the 
line of strike to the north-west, towards Selkirk and Melrose, the 
beds thicken, and bands of grit, flagstone, and conglomerate come 
in between the shale zones in definite and. recognizable order. But 
when followed at right angles to the strike from S.H. to N.W. 
transversely across the Uplands, the change is very much greater. 
The entire series thickens rapidly, and the black shale bands are 
replaced one by one from above by barren flagstones and shales, 
