On the Discovery of the Remains of Cephalaspidian Fishes in Devonshire and Cornwall; and on the Identity of Steganodictyum , M'Coy, with genera of those Fishes

Abstract

I beg to draw attention to a most important and interesting discovery which has been recently made in the cabinet of my late friend Lieut. Wyatt-Edgell. Mr. Salter, in looking through the collection, came upon a specimen of the supposed Sponge Steganodictyum Cornubicum , from the Lower-Devonian slates of Mudstone Bay, which, with his usual sagacity, that naturalist at once observed bore strong resemblance in shape and in structure to the shield of Pteraspids; and on comparison with other Specimens and M'Coy's figures, he came to the remarkable conclusion CJaat M'Coy's supposed Sponge is actually the cephalic plate of a Pteraspidian fish. Having, by the kindness of my friend Mr. Henry Woodward, had an opportunity of examining Mr. Wyatt-Edgell's specimens, and comparing them with Professor M'Coy's figures, I can most fully endorse Mr. Salter's determination—the nacreous, cancellated, and striated layers described by Professor Huxley, and so eminently characteristic of the Heterostracous Cephalaspidæ, by their presence leaving no room for doubt. It was obviously desirable that Mr. Wyatt-Edgell;s Pteraspid should be compared with the only other species known from beds of the same age, viz. the Scaphaspis Dunensis , originally described by Roemer as a Cephalopod. This Mr. Woodward and I were fortunately able to do, since the reputed single specimen of Roemer's fish-plate from Daun, in the Eifel, forms part of our National collection. Though the specimen from Devonshire is by no means as satisfactory an example as we may hope hereafter to obtain, it is sufficiently well preserved to indicate a