Mr. T. Attliey on Antliracosaurus Russelli. 147 



lying over the position of the great palatine teeth ; secondly, 

 the anterior end of the left ramus of the mandible lies trans- 

 versely across portions of the jugal, supratemporal, quadrate- 

 jugal, squamous, and parietal bones of the right side of the 

 cranium ; thirdly, in the left side of the cranium has been 

 imbedded a small vertebra, probably of the neck (this vertebra 

 seems to have been thrust forcibly in between the bones of the 

 upper wall and those of the under Avail or floor of the cranium) ; 

 fourthly, the posterior part of the left palate-bone overlies, on 

 the same side, parts of the jugal, quadrate-jugal, and supra- 

 temporal bones. The rest of the upper surface of the skull is 

 uncovered, and can be well seen. 



The skull oi Antliracosaurus is much broader in proportion 

 to its length, and altogether stronger, than that of Loxomma ; 

 and both of these are much larger and stronger than that of 

 PteroplaXj these three being the only large Labyrinthodonts as 

 yet found in our coal-field. 



Theupper surface of the skull oiAnthracosaurus is represented 

 in Plate VI 1 1. It is broadly triangular, with rounded ante- 

 rior and posterior angles, deeply concave between the posterior 

 angles, and slightly convex on the sides. It is not quite 

 perfect. Its right side or border, however, is so ; whilst from 

 its left side the maxillary bone has been displaced, and was 

 found imbedded in the same slab of shale at a short distance 

 from its proper position in the skull. Further, a portion 

 about an inch in breadth and three inches in length of the 

 iimer posterior border of the right maxillary extension, and an 

 inch of the posterior angle of the same extension of the left 

 side, are deficient. Moreover the right and left angles of the 

 occiput are also slightly deficient. 



The length of the skull along the median line, from the tip 

 of the snout to the posterior edge of the occiput, is 13| inches, 

 and from the same point to the ends of the maxillary prolonga- 

 tions 17 inches. The greatest breadth, 14 inches, is at 1| inch 

 in front of the ends of these prolongations. Over the posterior 

 ends of the orbital vacuities the breadth is 12 inches, over the 

 anterior ends of the same 10| inches, and at 3 inches behind 

 the snout 5| inches, inclusive of the breadth of the left maxil- 

 lary bone, which at this part is absent but has been estimated 

 at the same breadth as that of the right maxilla. 



The pitted sculpturing on the surface of the bones is more 

 irregular and more closely crowded about the snout than it is 

 on the skull of Loxomma ; and it is rougher and deeper on the 

 anterior than on the posterior region of the cranium. The 

 surface altogether has a rougher appearance than in Loxomma. 

 No glandular openings have been discovered at tlie bottoms 



