XVI. Notes on Carboniferous Fossils

Abstract

Professor Agassiz, in his Poissons Fossiles, published in 1837, described the genus Diplodus (sp. gibbosus and minutus ) from specimens, chiefly of dissociated teeth, found in the English coal-fields. Subsequently, a well-preserved fish was discovered in Bohemia, and described in 1847 by Goldfuss, who named it Orthacanthus Dechenii. In 1848, Professor Beyrich, of Berlin, described the same fish, and named it Xenacanthus Dechenii, founding on the fact that the spine had a greater similarity to Pleuracanthus than to Orthacanthus. At the meeting of the British Association in Glasgow, in 1855, Sir Philip Egerton, from discoveries that had been made in the interval, pointed out that the spines of Pleuracanthus and the teeth of Diplodus belonged, in fact, to the same fish. The specimens from which Sir Philip proved this to the Association were obtained from Carluke and Edinburgh. In 1867 Professor Kner went carefully over the remains of such fishes in the museums of Dresden, Berlin, Breslau, and Vienna. Although none of the specimens found in these museums were complete, yet in some of them he found the teeth of Diplodus minutus of Agassiz in position, and from the external aspect of the fossils he accepted Goldfuss’s generic name Orthacanthus Dechenii. The specimen which the author now exhibited had been for many years in his collection, and had been provisionally named Pleuracanthus minutus. After a careful examination, however, of the microscopic structure both of the teeth and the shagreen, he could find no relation between the structure of Pleuracanthus and that This 250-word extract was created in the absence of an abstract