ON A LABYKINTHODONT AMPHIBIAN. 215 



other specimen, at the right side. The only other feature worthy 

 of notice in our second specimen is the pterygoid ; that on the 

 left side is pretty well preserved, and shows no variation of cha- 

 racter, except that the surface is minutely striated in a longitu- 

 dinal direction. 



For three or four years past, Mr. Atthey has had in his pos- 

 session a mandible belonging to this new Labyrinthodont ; and, 

 though always believing it to be distinct from that of any known 

 species, we have kept it back till now, not feeling ourselves jus- 

 tified in encumbering the nomenclature with terms signifying so 

 little, and, in a scientific point of view, almost valueless. We 

 are now, however, in a position to associate it with a cranium 

 possessing important and interesting features. There can be no 

 doubt that this mandible is really that of Batrachiderpeton. The 

 surface -character of the bone, its size, and the character, form, 

 and size of the teeth all go to prove this. 



This mandible is perfect in front, where it is obtusely pointed ; 

 behind it is imperfect, a considerable portion evidently having 

 been removed. The outer surface is exposed, and is seen to be 

 covered with a few coarse, irregular, longitudinal ridges, having 

 much the character of those on the cranium ; and in front there 

 are a few reticulated ridges, quite similar to those on the prae- 

 niaxillaa. It is an inch long and a quarter of an inch broad at 

 the widest part ; the margins are nearly parallel, the jaw nar- 

 rowing only very slightly forwards ; the alveolar border is thick 

 and almost straight, there being a slight depression near the 

 centre, dividing the teeth into two groups. In all, there are 

 fifteen teeth ; they are closely arranged, stout, a little incurved, 

 rather obtusely pointed, and have the tips finely striated and 

 slightly compressed in the direction of the length of the jaw — 

 agreeing in these peculiarities, as in all the other characters, with 

 the prasmaxillary teeth. They are confined to the anterior por- 

 tion of the mandible, there apparently having been none in the 

 posterior part. The range of the teeth will therefore correspond 

 very well to those of the praarnaxilla. They are the sixteenth of 

 an inch in length, being of the same size as those of the prae- 

 maxilla. 



