568 POPULAR SCIENCE MONTHLY 



very short and articulated with the skull far in front of the ends of 

 the horns. No trace has been found of limbs, and the vertebrae inter- 

 lock like those of the modern snakes ; from this it is probable that these 

 animals were limbless and snake-like in form, but they must have 

 presented a most peculiar appearance with the slender body and 

 enormous head. It is hardly possible that the animal could have 

 raised its head from the ground except by an occasional and violent 

 effort, for the skull was solid and relatively very heavy. Probably the 

 animal was purely aquatic in habit and, lying in the mud of the bottom, 

 wriggled forward, pushing its great head through the slime, from which 

 it gathered the vegetation and small shell fish which formed its food. 

 The position of the eyes and nostrils on the top of the skull renders 

 this position the more certain. On the banks of the streams the am- 

 phibians took yet another form, for here they donned a complete coat 

 of mail similar to that of the small reptile. 



Imperfect as our knowledge still is of this wonderful group of 

 animals, enough is already known to show how fully strife and warfare 

 filled the world's history even at the beginning, and how every possible 

 advantage of tooth or limb or armor was necessary for success. 



