ON TWO NEW SPECIES OP LABYEINTHODONTS. 289 



17. On tiuo new Species of Labyeinthodonts. B)^ E. Lydekker, 

 Esq., B.A., F.G.8./&C. (Eead March 12, 1890.) 



[Plate XII.] 



A. Mcuidihle from the Carboniferous of Scotland, 



Exclusive of the smaller forms like Ophiderjpeton, Ce7'aterpeton, &c., 

 the Labyrinthodonts hitherto described from the British Carboniferous 

 comprise Antliracosaurus^ Lo.vomma, PJioUderpeton, and Fteroplax. 

 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 repre- 

 sent the upper part of the English Mountain-Limestone (Lower 

 Carboniferous). Pteroplax is from the Coal-Measures of Northum- 

 berland. Several other generic names have, indeed, been applied by 

 Mr. T. P. Barkas t to remains of reputed Labyriuthodonts from 

 the Coal-Measures of Northumberland ; but such of these spe- 

 cimens as are truly referable to the group in question appear to 

 belong to Loxomma and Anthracosaur^is. It is important to 

 observe that a jaw from the Lower Permian (Rothliegendes) of 

 Bohemia has been referred by Dr. Eritsch J 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 Pholidof /aster 

 are represented by species of much smaller size than the others : 

 and since it is quite evident that they have no afHnity with the 

 specimen I am about to describe, it will be unnecessary to make any 

 further mention of them. 



In Loxomma the teeth are characterized by the large size of the 

 crowns, which are straight and laterally compressed, with very 

 prominent fore-and-aft carinae, so that they present a striking 

 resemblance to some types of spcar-hcads. These teetli have a 

 highly polished and nearly smooth surface ; and in the lower jaw 

 their arrangement is very irregular. Further, the outer surface of 

 the mandible is entirely covered with a net-like sculpture, and the 

 depth of the ramus is not very great. 



In Antli7'acosauriis, on the other hand, the teeth (as described by 

 Mr. Atthey) have subcylindrical crowns, without fore-and-aft 

 carina), and with an oval transverse section at the base, of wliich the 



* See Quart. Journ. Geol. Soc. ^ol. xix. p. 50, note. 



t * Coal-Measure Pahvvintology.' 



X ' Fauna der Gaskolile,' etc. vol. ii. p, 1(). 



