On the Geology of Moffat^ Dumfriesshire. 385 
of the contained fossils. He examined the shales at Hart- 
fell Spaw, but noticed only their mineralogical appearance, 
and failed to observe the graptolites which abound in them. 
An anonymous critic, evidently acquainted with the rocks of 
the district, says, in a review of Dr Jameson's work, in the 
Literary Journal for 1806, We know that vegetable petri- 
factions are very common in the greywacke slates of Dum- 
friesshire." The graptolites, which this unknown writer had 
evidently observed, remained unnoticed yet for many years. 
It seems scarcely possible that the keen eye of Dr "Walker 
could have failed to see them. He says, " During my long 
residence at Moffat I collected, in a number of short tours, 
all the remarkable minerals of Dumfriesshire." We cannot 
now ascertain to what extent the structure and peculiarities 
of the district had been determined by him, because of the 
unfortunate loss of all his papers. It was not till the year 
1850 that Harkness, Sedgwick, Murchison, and others, 
again drew attention to the rocks of the district, and re-dis- 
covered the forgotten " vegetable petrifactions." In the in- 
terval much had been done to determine the structure and 
position of the rocks of the south of Scotland, by Maclaren, 
Nicol, and Sedgwick. Professor Harkness, in his valuable 
and interesting papers published in the " Geological Journal," 
1851, refers the rocks of the district to the Caradoc sand- 
stone, from the characters of the graptolites. He describes in 
detail the anthracitic shales. An examination of their vari- 
ous localities led him to the conclusion that there was an 
anticlinal axis at Dryfe Water, that the strata north of this 
dipped northv/ards, and those south dipped southwards, and 
that the frequent recurrence of the graptolitic shales was pro- 
duced by three faults — the various localities grouping them- 
selves, as he supposed, into three series. Sir R. Murchison, 
while travelling from Dumfries to Moffat in the same year, 
supposed that the axis existed to the north of the former 
town, and published this opinion in his " Siluria," 1854, con- 
sidering it identical with that of Harkness, and using one of 
that gentleman's diagrams to illustrate his views. 
This is the generally received theory of the structure of the 
districts. 
