CLASPING ORGANS OF AMPHIBIA. 259 



resemble the ancient species. In the Miocene rocks of Switzer- 

 land occurs the famous Andrias scheuchzeri Tschudi, which is 

 related to the Japanese salamander of to-day. In the Pleistocene 

 are found remains which belong to species of modern genera. 



That the transition between the ancient and the recent forms 

 took place between the close of the Permian and the close of the 

 Cretaceous is evident. This transition consisted in the loss of 

 the ventral armature, the loss of sclerotic plates, the loss of der- 

 mal plates, the loss of the bony clasping organs, the loss of the 

 supra-occipital and epiotic elements from the skull and the loss 

 of strong teeth. The modern Amphibia are degenerate in struc- 

 ture. The bridge which may help to close the gap between the 

 Paleozoic and the Mesozoic forms is the fact that similar bony 

 clasping organs are, apparently, developed in the forms of the 

 two periods. If this be true it will be of service in closing one 

 of the widest gaps in vertebrate phylogeny. 



