MANDIBULAR BAMUS OF ANTHRACOSAURUS RUSSELLI. 889 



to ; only it is very much larger, and must have belonged to a 

 jaw equal in size to that from Fenton. In fact, from its dimen- 

 sions and massive character, it would seem more than probable 

 that this Newsham articular piece really belongs to Anthraco- 

 saurus. 



The posterior margin of the fragment of the ramus in con- 

 nexion with the articular piece is perfect, and sweeps downwards 

 in an even curve, which, if continued a little further, as it ap- 

 pears to have been, would give to the posterior part of the jaw 

 a depth of quite four inches — the measurement near the same 

 point of Mr. Ward's specimen. The articular piece stands well 

 up ; the neck is short and stout ; the process bearing the glenoid 

 surface is massive, and is transversely elongated, measuring two 

 inches and a quarter long, and an inch wide ; the glenoid cavity 

 is deep, and takes a slight sigmoid curve ; behind at the outer 

 margin there has been a stout projecting process ; and in front 

 towards the inner margin there has been a similar projection 

 of the lip of the articular cavity. It would therefore seem evi- 

 dent that the attachment of the mandible to the tympanic troch- 

 lea must have been very firm, rendering the movements of the 

 jaw secure and precise. Indeed, the massive character of the 

 whole articular piece indicates great power, and is well corre- 

 lated with the huge vomerine tusks and formidable dentition of 

 this species. 



The presence of Anthracosaurus in the Newcastle Coal-field 

 does not reBt merely on the occurrence of this articular piece. 

 We have already alluded to a large portion of the cranium that 

 was found at Newsham. This interesting specimen exhibits 

 numerous maxillary teeth and the two great vomerine tusks so 

 characteristic of this powerful Labyrinthodont. The anterior 

 extremity of a mandibular ramus, with five teeth attached, was 

 also described in the same paper with the last-named specimen. 

 And now we have to record from the same locality a fragmentary 

 specimen of the middle portions of a pair of mandibular rami 

 displaying several teeth. These fragments lie one over the 

 other, and are much confused and mixed up with some other 

 bones that are adherent by pressure to the general mass. The 



