OK ANTHKACOSAURUS. 319 



in the Scotch specimen : they are a little compressed above ; and 

 one, which is tolerably perfect, has the apex slightly carinated. 



On making a section of one of the teeth, it is quite obvious 

 that the ridges on the surface are owing to erosion, if not en- 

 tirely, at least mainly, and that the internal structure agrees 

 very well with that of Anthracosaurus when allowance is made 

 for the variation caused by the sections not being made at the 

 same part. Our section was made a little way up the tooth; 

 while those of the Scotch specimens were, as we have already 

 explained, evidently made close to the base. 



There can therefore be little doubt that this fragmentary man- 

 dible really belongs to Anthracosaurus. We have, then, the 

 satisfaction of recording the occurrence in the Northumberland 

 Coal-Field, not only of a considerable portion of the cranium, 

 but likewise of a large fragment of the jaw of this rare fossil. 



The large sternal plate, nearly five inches long, described in 

 our paper on Pteroplax,'''' is probably that of Anthracoscmrus. It 

 was found in the same locality, and this is the only large Laby- 

 rinthodont occurring in the Newsham shale to which it can at 

 present be assigned, We also possess some ribs and vertebrae 

 which perhaps belong to the same animal. 



XV. — Note on Anthracosaurus. By Albany Hancock, F.L.S,, 

 AND Thomas Atthey. 



In the following brief remarks, we wish to supply a note to our 

 paper on Anthracosaurus and Urocordylus, published in the Sep- 

 tember number of the "Annals." In that paper we described a 

 large portion of the skull of Anthracosaurus, and a portion of a 

 mandible belonging also to the same Labyrinthodont. We spoke 

 likewise of the occurrence of a central sternal plate, ribs, and 

 vertebrae which we thought belonged to that Amphibian. We 

 are now in a position to show that another considerable frag- 

 ment of a skull of this interesting Labyrinthodont has occurred 



* See Annuls of Nat. Hist., Scr. 4, Vol. I., \\ 277. 



