Neio Fossil BeptUes. ' 41 



Owing to the very imperfect condition of the skull and to the 

 absence of the limbs, it is difficult to say much with any degree of 

 certainty on the affinities of the animal. From the notochordal con- 

 dition of the vertebrae, the structure of the lower jaw, the shoulder 

 girdle, pelvis, and the abdominal ribs, we may fairly confidently 

 place it at least in the Diaptosauria, but beyond this we can only 

 vaguely speculate. There seems to be considerable resemblance to 

 Mesosaurus — the elongated slender jaws, the anchylosis of the 

 elements of the shoulder girdle, the notochordal vertebrae, and the 

 plate-like pelvis — and on the whole the affinities are perhaps more 

 with the Mesosauria than with any other order. The pelvis is a 

 little more advanced, the teeth are of a higher type, and the abdo- 

 minal ribs much better developed ; but* these points are not enough 

 to remove it from the group, and provisionally, till the head and 

 limbs are better known, the form may be placed in the Mesosauria 

 or Proganosauria. 



