148 
SILUKIA. 
[Chap. VIII. 
South Wales. The series terminates upwards in strata which, on the 
banks of the Lune and near Kendal, are the counterparts of the uppermost 
zone in the Silurian region, and are charged with numerous fossils, some of 
the most striking of which are large Crustaceans (Ceratiocaris, Eurypterus, 
&c, see p. 140)*. As the district around Kendal is now undergoing the 
critical survey of that experienced Silurian geologist Mr. Aveline, we may 
be sure that these rocks of Cumberland will be placed in precise correla- 
tion with the types of Shropshire and North Wales, and their outlines 
accurately denned. 
In this district, however, the ascending succession is interruptedf . In- 
stead of the complete series of the Old Red Sandstone, which has been 
described in Shropshire and Herefordshire, and a conformable gradation 
and passage upwards into its overlying sandstones and marls, the Silurian 
rocks of different age are at once unconformably flanked and overlapped 
by red masses, chiefly coarse conglomerates, which alone represent the 
great and complex Devonian group of other tracts. 
Isle of Man. — In correlation with their observations on the Lake country 
of Cumberland and Westmoreland, Messrs. Harkness and Nicholson have 
shown that the oldest rocks in the Isle of Man are of Lower Silurian age, 
and evidently of the same date as the Skiddaw slates, not only on account 
of their lithological character, but also from their containing the common 
Skiddaw fossil Palseochorda majorf. 
Silurian JRocks of Scotland. — In the early days of Scottish geology, its 
illustrious founders, Hutton and Playfair, considered the schistose moun- 
tains in the South of Scotland to be void of all traces of life, until their 
able associate, Sir James Hall, detected a few fossil shells in a limestone at 
Wrae Hill, in Peebles -shire, which had been regarded as ' primary.' The 
merit of transferring these strata to what was then termed the ' transition 
class ' of rocks, or those recognized as old fossiliferous deposits, is also in 
great measure due to the late Professor Jameson ; for though he valued 
lightly organic remains, as was then usual with the scholars of Werner, he 
gave a clear general view of the rocks. 
It was not until some years after the publication of the ' Silurian System' 
that the researches of Professor Nicol first indicated the relations of the 
Wrae fossils and the associated schistose masses to the known members of 
the series § ; and since then other researches of that author, as well as 
* The reader who desires to study the data by hitherto unnoticed inlier of Silurian rocks around 
which our present knowledge of the geology of Dufton Pike). 
the Lake district has been acquired, must read t Besides this general transgression and uncon- 
the various memoirs of Professor Sedgwick in fortuity, it has been pointed out by Professor 
the Proceedings of the Geological Society, vol. ii. Sedgwick that the 4 Old Eed' contains many frag- 
p. 675, and the Quart. Journ. Geol. Soc. vol. i. ments of the Silurian Tilestones, which must have 
p. 442, vol. ii. p. 106, vol. iii. p. 133, vol. iv. p. 216, been solid before the conglomerate was formed 
vol. viii. pp. 35, 136 ; the Memoirs of Mr. D. (Quart. Journ. Geol. Soc. vol. i. p. 449). 
Sharpe, Proc. Geol. Soc. vol. iv. pp. 23, 70; those I Quart. Journ. Geol. Soc. vol. xxii. p. 488. 
by Professor Phillips, Geol. Trans. 2nd ser. § For a complete historical sketch, see a notice 
vol. iii. p. 1, and vol. iv. p. 95 ; and Professor by Mr. Hugh Miller (' Witness ' newspaper, Nb- 
Harkness's important descriptions of the rocks vember 24th and 27th, 1852). A single fossil was 
and fossils of Cumberland and Westmoreland, found, but not described, by Laidlaw, the friend 
in the Quart. Journ. Geol. Soc. vol. xix. p. 113, of Walter Scott ; and Orthoceratites were after- 
&c. (where, with Mr. Salter, he describes many wards discovered by Mr. Charles Maclaren in the 
Silurian fossils new to the country), and in Pentland Hills, and noticed in his excellent work 
vol. xx. p. 235 (where he gives an account of a ' The Geology of Fife and the Lothians,' 1839. 
