Prof. C. Lapworth—Ballantrae Rocks of South Scotland. 65 
Such I have long held to be the general structure and succession 
of strata! of the Lower Paleozoic region of the Southern Uplands, 
as deduced from the facts and conclusions essentially dependent 
upon the zonal method of stratigraphy. Upon this view the 
sequence, lithology and paleontology of the several recognizable 
zones of strata in the Upland region become mutually intelligible, 
and the various rock-formations and their fossils admit of satis- 
factory parallelism with those of the corresponding Proterozoic 
deposits of other districts both in Britain and abroad. See the 
accompanying table on page 66. 
It may be objected by some of those geologists who are familiar 
with the literature of discovery and speculation among these South 
Scottish rocks, that these views are opposed to those advocated by 
previous observers.? But I believe that this opposition is more in 
appearance than reality. The physical facts and phenomena upon 
which the earlier views of the succession were based remain 
unquestioned. They are here, however, supplemented by the 
conclusions drawn from the abundant stratigraphical and paleeon- 
tological discoveries of the last fifteen years, and have received the 
only interpretation which seems to me to be possible in the present 
state of our knowledge. We have to recollect that all the earlier 
views of the succession were based almost exclusively upon the 
very natural theory that the Hawick-Dumfries axis is a true anti- 
clinal form, and the Sanquahar-Moorfoot axis is a true synclinal, 
propositions upon which no one familiar with our actual knowledge 
of the stratigraphical phenomena of mountain regions would at the 
present day place the least reliance; while at the time when the 
very latest of these earlier schemes was published, the paramount 
value of the Graptolite as a geological index was unknown and 
unsuspected. The lithological “groups” of these earlier and local 
classifications fall naturally into their proper places in the present 
scheme, and find their simple interpretation as successive geogra- 
phical bands in the same great Lower Palzozoic succession as it 
slowly changes in thickness and lithology when followed from the 
shore line into deeper water: while, under this arrangement, 
their formerly conflicting Graptolitic faunas show the same sequence 
they hold over the rest of the Lower Paleozoic world. The present 
views have also this further recommendation that they depend upon, 
and necessitate, the harmony of all the ascertainable phenomena— 
geographical position, thickness, lithology, local sequence, and pale- 
ontology—and admit of being tested in each of these characters 
in the field at every stage, and of being confirmed, extended 
and corrected as discovery progresses. 
But although I hold that all the known facts and phenomena 
bearing upon the sequence of the rocks of the Southern Uplands 
1 Compare Lapworth, Transactions Geol. Soc. Glasgow, 1878, pp. 78 to 84, etc. 
2 Sedgwick, 1849, Rep. Brit. Assoc. p. 103; Nicol. Q.J.G.S, 1850, p. 53; 
Murchison, ibid. 1851, p. 187; Siluria, 4th edition, pp. 148-158; A. Geikie, Trans. 
Geol. Soc. Glasgow, 1867, p. 74; Explan. Sheet 3, Geol. Survey Scotland, 1873, pp. 
4-18; ibid. sheet 14, p. 9, etc. 
DECADE III.—VOL. VI.—NO. II. 5 
