148 AMPHIBIA AND PISCES OF THE PERMIAN OF NORTH AMERICA 



The foregoing description, with the original description quoted, gives 

 about all we know of this creature. It is certain that it was an aquatic form 

 with a very slender body, short legs, and a powerful tail. It was probably 

 the most active of the amphibia of its time, rivaling in its speed and aggres- 

 siveness the contemporary Reptilia. Its form and general adaptations sug- 

 gest that it occupied a position in the animal world similar to that of the 

 more slender and active Crocodilia to-day. 



Moody has recently (62) noted the occurrence of an embolomerous 

 form in the Mazon Creek deposits. He regards it as related to Cricotus 

 and belonging in the family Cricotidce. "It differs from Cricotus, however, 

 in the form of the centrum, and the relatively greater length of the com- 

 ponent elements. The notochordal canal is widely open." 



