On Dorypterus Hoffmanni , Germar, from the Marl-slate fo Midderidge, Durham

Abstract

Within the last few years four specimens of Dorypterus Hoffmanni have been discovered in the Marl-slate of Midderidge, in the county of Durham, by Joseph Duff, Esq., two of them in the year 1865, and the other two in the autumn of last year, 1869. A few traces of other individuals were also observed at the same time and in the same locality. These are, we believe, the first specimens of this very singular fish that have been obtained from the Marl-slate of this country. The Midderidge quarry, in which these examples were found, is situated on the Darlington and Wear Valley Railway, not far from Bishop’s Auckland, and is well known as being the locality where the Marl-slate fishes were first discovered. Prof. Sedgwick a long time ago (Trans. Geol. Soc. 2nd series, vol. iii. pp. 76, 77) accurately described the position of this quarry and the stratum in which these specimens were found. Through the kindness of Mr. Duff, we have had the opportunity and pleasure of examining and studying all the specimens of this interesting fish: and this has happened fortunately; for each specimen, being in a different state of preservation, has assisted much towards the working out and comprehension of the structure of this extraordinary ichthyolite. When Mr. Driff’s original specimens were first seen, they were supposed to be merely the skeletons of a species of Platysomus ; but a short examination soon showed that this opinion was entirely erroneous; and happily the discovery of two