ON A LABYEINTHODONT AMPHIBIAN. 213 



half the length of the skull ; it is divided by a suture on the 

 longitudinal middle line, and the two lateral portions diverge a 

 little behind. To these diverging points the pterygoids are at- 

 tached ; they are wide, stout bones, which, passing outward and 

 backward, abut at the posterior portion of the malars or the 

 bones forming the hinder lateral margins of the skull. In front 

 of the pterygoids there is a large depression on each side, which 

 may be the palato-temporal foramen : these depressions are cir- 

 cular in front ; but their inner posterior boundaries are formed 

 by the almost straight line of the pterygoids. 



On the middle longitudinal line behind the pterygoids there is 

 an elevated process, which probably indicates the presence of 

 the sphenoid ; and behind this, on either hand, at the posterior 

 margin of the skull, which is bounded by a strong ridge, there 

 is a rounded elevation. These two elevations are probably the 

 occipital condyles pressed inwards ; or it may be that they are 

 the lateral margins of the sphenoid turned upwards and distorted. 



The large plates in front, which we have assumed to be the 

 vomers, may possibly hold in combination the palatal bones. 

 Be this, however, as it may, they are thickly covered with mi- 

 nute teeth from end to end, and to within a short distance of 

 the lateral margins. These teeth do not appear to be arranged 

 in any particular order, but are much obscured by the matrix. 

 A few, however, are quite free, and show that they are short, 

 stout, pointed, conical, and have the apices striated. This great 

 patch of minute teeth is bounded on either side by a row of 

 eight or ten stout close-set teeth, similar in all respects to the 

 prsemaxillary teeth, even to the apical compression and stria- 

 tion ; and they are nearly as large, if not quite as large, as the 

 latter. The posterior one, which is placed close in front of the 

 palato-temporal foramen, is larger than the rest, and is certainly 

 equal in size to the prsemaxillary teeth. 



The other or less perfect specimen of the skull has lost the 

 whole of the right side ; and the margin of the left side is much 

 injured, and is doubled inwards. It is quite evident, however, 

 that this specimen, when perfect, was quite as large as the one 

 first described ; and the surface -ornamentation is of the same 



