Amphibian from the . Coal-shale of Newsham. . 63 
very striking. The extensive development of this vomerine 
armature, and the deficiency of bony maxilla, would seem to 
ally Batrachiderpeton to Siren and Proteus; while the rela- 
tionship of the vomers to the pterygoids, and the form of the 
latter, are very similar to what obtains in Axolotl. And the 
alliance with this interesting form would be rendered still 
stronger if it should turn out that our new genus has reall 
bony maxille, particularly as the premaxille are armed wit 
teeth. In Stren and Proteus the premaxillaries are quite mi- 
nute, and are devoid of teeth. 
The characters of the premaxille in Batrachiderpeton are, 
as we have seen, only imperfectly displayed, and some 
as to their form and extent might be entertained. But it would 
seem likely that in them we see the whole of the bones of the 
upper jaw, and that they must have stretched outwards and 
backwards, and have each been united toa membrane orcartilage 
(the representative of the maxilla), and in this way have be- 
come attached to the under surface of the malar or the lateral 
cranial bone where it is smooth and seems well fitted for such 
attachment ; they could not have been attached to the outer 
edge of it, for it is covered with surface-ornamentation. By 
this arrangement spaces for the orbits are provided ; and thus, 
again, our new Labyrinthodont would seem to resemble Siren 
and Proteus, 
_ That this is the fact is apparently corroborated by what can 
be traced of the bones themselves. The premaxilla of the 
efore, it is wide, and is continuous with the bone of the 
ment. Behind, however, it appears to have been free, and to 
seem fair to assume that the premaxille comprise the whole 
of the bony structure of the upper jw. At the same time it 
must be allowed that, as previously pointed out, the row of 
teeth on the left side of the vomer in one of the specimens has 
much the appearance of having belonged to a maxilla ; and if 
this should prove to be the case, then Batrachiderpeton would 
be more closely allied to Axolotl than to Siren. 
