Merriam. — New Mamie Reptile. 



77 



The heavy splenials extend posteriorly only a short distance 

 behind the dentaries before they begin to thin out rapidly. Ante- 

 riorly they are suddenly widened to meet in the symphysis. The 

 transverse diameter of the splenials at the symphysis is more 

 than twice their width behind this region. In front of the sym- 

 physis the splenials extend downward to form a part of the lat- 

 eral face of the jaw. 



The dentaries extend backward a short distance over the an- 

 terior ends of the supra-angulars, and are also in contact infe- 

 riorly with the anterior extension of the angular. Like the sple- 

 nials, the dentaries are much expanded transversely in the sym- 

 physial region. The posterior ends extend backward as wing-like 

 projections for a short distance behind the symphysis. 



Situated on the dentaries are numerous small, button-like 

 teeth, somewhat similar to those of some of the pycnodont fishes. 

 The crowns are circular in cross-section, and the elevation is con- 

 siderably less than the transverse diameter. There are at least 

 three rows of teeth preserved on the right dentary, parallel with 

 the median border. On the left dentary, teeth extend from the 

 median line more than half of the distance to the outer margin, 

 and appear to have been in numerous rows. The surface of the 

 dentigerous area seems to have been convex. 



A portion of the palatine region is fairly well exposed in the 

 lower view of this specimen (pi. 9). The two large elements 

 separated posteriorly, but uniting medially opposite the posterior 

 ends of the splenials, are evidently pterygoids. Anterior to them 

 on either side are apparently the palatines. Extending backward 

 from a point a little in advance of the middle of the pterygoids 

 is a median space which possibly represents the posterior nasal 

 opening. On the superior side of the specimen (pi. 8) the struc- 

 ture is more indistinct. One of the palatine elements appears, 

 viz.: a part of one of the pterygoids. In addition to this, two 

 heavy bones (a) with lateral notches are situated just behind the 

 symphysis. Posterior to these is a large expanded element (&), 

 and a large emarginate bone (c). The flat posterior element may 

 belong to the roof of the cranium. The laterally notched anterior 

 bones might be vomers, or possibly premaxillaries. The large 

 crescentic bone may pertain to the postorbital region. 



