225 
In 1836 and 1837 also*, Messrs. Sedgwick and Murchison pro- 
posed to transfer the culmiferous or anthracitic shale and grits (Shil- 
lot and Dunstone) of North Devon to the carboniferous system ; 
withdrawing them from the grauwacke in which they had before 
been included, and thus assigning a much more recent date than 
heretofore to the strata which occupy nearly one third part of the 
map of Devonshire. 
But the relations of the slates and limestones of South Devon still 
remained to be determined ; the mineral characters of the former 
being different from those of the old red sandstone beneath the car- 
boniferous group, in many parts of South Wales and in Hereford- 
shire, while the true position of the limestones (e. g. those of Ply- 
mouth, Torbay, and Newton Bushell, ) was doubtful. At this period, 
(1837,) the fossils of this district were examined by Mr. Lonsdale 
and Mr. Sowerby, to whom the organic remains, both of the car- 
boniferous and Silurian systems, were familiar. It was soon per- 
ceived, that while some of the South Devonshire fossils approached 
to those of the carboniferous strata, and others to those of Siluria, 
there were still many species which could not be assigned to either 
system; the whole, taken together, exhibiting a peculiar and inter- 
mediate paleontological character. Mr. Lonsdale therefore sug- 
gested, that the difficulties which had perplexed this inquiry could 
be removed by regarding the limestones of South Devon as subor- 
dinate to slaty rocks, which represent the old red sandstones of Here- 
ford, Wales, Scotland, and Ireland,—their true place in the series of 
Devonshire being intermediate between the culmiferous basin of 
North Devon, and the Silurian strata,—if the latter exist in that 
county. 
The value of this suggestion was not at first appreciated; but 
after the lapse of more than a year, Mr. Lonsdale’s views were 
adopted (March 1839) by Messrs. Sedgwick and Murchisont, who 
* Tn August 1836, at the Meeting of the British Association at Bristol; 
and in a paper read before the Geological Society, May and June, 1837, 
now published in the Geological Transactions, Second Series, vol. v., Part 3. 
+ Itis to be observed here, that Mr. Murchison, having previously shown 
that the fossils of the Silurian era are distinct from those of the carboni- 
ferous period, had also pointed out ‘‘ the vast accumulations” (in which 
few fossils had at that time been discovered) ‘‘ then known to separate the 
two systems.” He mentions especially, that ‘‘the fishes of the old red 
