On two new Species of Labyrinthodonts

A. Mandible from the Carboniferous of Scotland. Exclusive of the smaller forms like Ophiderpeton , Ceraterpeton , &c., the Labyrinthodonts hitherto described from the British Carboniferous comprise Anthracosaurus , Loxomma , Pholiderpeton , and Pteroplax . Of these the type specimen of Anthracosaurus was obtained from the Coal-Measures (Upper Carboniferous) of Lanarkshire ; while the types of the second and third genera come from the ironstone of Gilmerton, near Edinburgh, which is generally considered to represent the upper part of the English Mountain-Limestone (Lower Carboniferous). Pteroplax is from the Coal-Measures of Northumberland. Several other generic names have, indeed, been applied by Mr. T. P. Barkas to remains of reputed Labyrinthodonts from the Coal-Measures of Northumberland; but such of these specimens as are truly referable to the group in question appear to belong to Loxomma and Authracosaurus . It is important to observe that a jaw from the Lower Permian (Rothliegendes) of Bohemia has been referred by Dr. Fritsch to a species of Loxomma , thus indicating, if the determination be accepted, the persistence of this generic type from the Lower Carboniferous to the Lower Permian. The Northumberland specimens indicate the occurrence of Loxomma in the Coal-Measures ; while a specimen in the British Museum leads me to conclude that Anthracosaurus dates from the Lower Carboniferous of Burdie House. Of the four genera mentioned above, Pteroplax and Pholidogaster are represented by species of much smaller size than the others : and since it is quite evident that they have no affinity with the specimen I am about to describe, it will be unnecessary to make any