86 REPORT—1862.. 
Torquay, in South Devon. 1t would seem that this identification has-not been 
considered perfectly reliable, since the fossil has not found a place in subsequent 
works on the Devonshire beds, or in Professor Morris’s Catalogue of British 
Fossils. 
The mineral and mechanical characters of the Old Red rocks may, perhaps, suf- 
ficiently explain the absence in them of mollusks and other dwellers at the sea- 
bottom ; but there seems no satisfactory mode of accounting for the non-appearance 
of fishes in the slates and limestones of Deyon and Cornwall. We are asked, by 
one proposed solution of the problem, to suppose that some geographical difficulty 
or barrier separated the two areas and prevented the migration and mingling of 
their inhabitants ; whilst another suggests that the Old Red fish were probably at 
home in fresh water only, and ought not to be looked for in beds so decidedly ma- 
rine as those of Deyon and Cornwall. 
The interesting and important discovery, by Sir R. I. Murchison *, of the inter- 
mixture, in the same Devonian bed in Russia, of the fish of the Upper and Middle 
Old Red of Scotland with the shells of Devonshire seems to dispose of the latter 
of the two proposed solutions just mentioned, but leaves the difficulty untouched ; 
nor does it appear that the synchronism of the representative beds in Britain neces- 
sarily flows Boe it. It proves, of course, that the fish and shells lived at one and 
the same time in Russian, not that they did so in British, waters. We may have 
an example here of the distinction between geological contemporaneity and syn- 
chrony, so ably pointed out, on a recent occasion, by Professor Huxley 7. 
At the Meeting of the British Association held at Cork, in 1843, Mr. Peach 
brought under the notice of the Geological Section certain fossils which had then 
recently been found, by Mr. Couch, in the Devonian slates of Polperro, in Cornwall, 
The pulsiontologiste to whom they were then submitted considered them to be the 
remains of fishes; this was the opinion also of the late Mr. Hugh Miller at first, 
but subsequently he considered them to be very doubtful and extremely puzzling ; 
ultimately they were pronounced, by Professor M‘Coy and Mr. Carter, of Cambridge, 
to be sponges merely. It may still be doubted, however, whether certain fossils 
found with them were not true ichthyolites; indeed, one specimen which, a few 
years since, I found in the same beds at Looe, in Cornwall, has been pronounced by 
Sir,P. Egerton and others to be a decided ichthyodorulite{. It has not been iden- 
tified, however, even generically. 
A few weeks since, I had the good fortune to find a fossil in the Plewrodictyum 
slates at Meadfoot, near Torquay ; that is, in certainly the lowest group of the rocks 
of South Devon, and which Sir R. I, Murchison has placed on the horizon of the 
Cephalaspidian and Pteraspidian beds—the lowest of his divisions of the Old Red of 
Scotland. The fossil was at once identified by Mr. Davies, of the British Museum, 
as a scale, or rather a portion of one, of Phyllolepis concentricus, Agass.—a fish 
known only by its fossil scales, which have hitherto been found only in the Clash- 
binnie beds, belonging to Sir R. I. Murchison’s “ Upper Old Red.” 
This fossil, then, appears to necessitate the belief, either that the organism which 
it represents had a greater vertical range than has been supposed (that is, that it 
belonged to the Lower and Middle, as well as Upper, Old Red fauna), or that the 
Pleurodictyum beds of Devon and Cornwall, instead of being on the horizon of the 
Lower, are on that of the Upper Old Red Series of Scotland. 
To accept the first of these (apparently the only two) alternatives would be to 
accept the difficulty of supposing that Phy/lolepis dates from the times of Cephalaspis, 
the extinction of which it witnessed, as well as the subsequent introduction and 
withdrawal of Coccosteus, Asterolepis, and others; and yet that, unlike its early 
contemporaries, it failed to leave any trace of its existence in the Old Red rocks, 
save only in the uppermost of their three groups. 
Rejecting this, however, we seem compelled to adopt its rival, which amounts 
to this:—There are in Devon and Cornwall no representatives of the Lower and 
Middle Old Red rocks of Scotland, but the Lowest (the Plewrodictyum) beds of 
the former are on the horizon of the upper division of the latter,—an opinion in 
* Siluria, 3rd edition, p. 382. 
+ Anniversary Address, Quart. Journ. Geol. Soc. vol. xvii. p. 40, &e. s 
t See ‘ Geologist,’ vol. iv. pl. 6, p. 346. 
