1911] Merriam: Saurian Fauna of Spitzbergen. 



319 



Wiman's studies of M.(f) nordenskioldii make possible for 

 the first time a fairly satisfactory suggestion as to the affinities 

 of this form. From a study of the excellently preserved material 

 of this species Wiman has been able to show the close similarity 

 of this form to Mixosaurus cornalianus from the Besano beds of 

 northern Italy, and also to the imperfectly known Cymbospon- 

 dylus( ?) natans from the Middle Triassic of the West Humboldt 

 Range in Nevada. 



Fig. 1. Mixosaurus (!) nordenskioldii (Hulke). A portion of the lower 

 jaw with dentition. Natural size. (After Wiman). 



Fig. 2. Mixosaurus (?) nordenskioldii (Hulke). Upper jaw fragment 

 with dentition. Natural size. (After Wiman). 



The skull of M. (?) nordenskioldii is known only by a few 

 fragments. Fortunately in many instances these pieces bear 

 teeth, so that some important characteristics of the dentition 

 appear. As was shown by Dames, the dentition is thoroughly 

 differentiated. The posterior teeth are low, laterally-compressed 

 domes, the anterior teeth are small, approximately conical, and 

 round in cross-section. The roots are coarsely folded as in the 



