456 
THE GEOLOGIST. 
some distance on its surface, apparently making the transverse tracks by- 
means of its tarsi." A figure of this insect-track would have been very 
acceptable in connection with the subject treated of in my above-mentioned 
paper, loc. cit. p. 132, etc. 
T. EuPEET Jones. 
Boyal Military College, Sandhurst. 
BEITISH ASSOCIATION MEETING AT CAMBEIDGE. 
ON THE COHELATION OF THE SLATES AND LIMESTONES OF 
DEVON AND CORNWALL WITH THE OLD RED SANDSTONES 
OF SCOTLAND. 
By W. Pengellt, F.a.S. 
The distinguished author of ' Siluria,' as geologists well know, has made 
a tripartite division of the slates and limestones of Devon and Cornwall, 
as well as of the Old Red Sandstones of Scotland, South Wales, etc., 
and given chronological equivalency to the upper, middle, and lower 
groups of each respectively. Thus he places the Barnstaple and Pether- 
win beds — the latter being characterized by the presence of Clymenia 
and Cypridina — on the horizon of the Upper Old Tied, with its Jlolopty- 
chius and Phi/Ilolepis ; the limestones of Torquay, Newton, and Plymouth, 
in which are found Stringocephalus, Calceola, Bronteiis, Acerviilaria, etc., 
are made to synchronize with the deposits of Caithness, etc., containing 
the remains of Asterolepis , Coccosteus, etc. ; whilst the slates of Meadfoot, 
etc., in South Devon, and Looe, etc., in Cornwall, distinguished by the re- 
markable Coral Pleurodictyum prohlematictim, are regarded as the equiva- 
lents in time of the Lower Old Eed rocks of Forfar and the North-east 
Highlands, which are charged with Ceplialaspis, Pteraspis, and OncJius* 
Though this co-ordination may be said to have met a large acceptance, 
it is not in keeping with the opinions of some who laboured long and sedu- 
lously amongst the older rocks of Devon and Cornwall, nor is it un- 
challenged by some existing writers. The late Sir Henry De la Beche re- 
garded " the bulk of the Devonshire and Cornish rocks as, at least in 
part, equivalent to the lower beds of the Carboniferous Limestone, to the 
passage beds between the Old Bed Sandstone and Carboniferous Lime- 
stone of Ireland, South Whales, etc., and also to some portion of the 
higher part of the Old Eed Sandstones of Herefordshire and adjacent 
districts. "t The Eev. David W^illiams considered " the Devonian system 
as occupying an enormous interval between the Old Eed Sandstone and 
Mountain Limestone.";}; Mr. Page says, " We shall use the term ' Devo- 
nian ' as applying more particularly to the strata as developed in the 
south of England, and the term ' Old Eed Sandstone ' as more especially 
applicable to those of Scotland ; believing, as we do, that the Caithness 
and Forfarshire beds are on a lower horizon than the English Devonians, 
and that it requires both developments to constitute the ' system ' as at 
present understood by European and American geologists. "§ Mr. Bete 
Jukes says, " It is quite possible that the slates and limestones of Devon, 
* 'Siluria,' Srd edit., p. 433. 
t Memoirs Geol. Survey, vol. . p. 103, 
+ Report Royal Geol. Soc. of Cornwall, 1843, p. 123, 
§ ' Advanced Text-Book of Geology,' p. 123, 
