THE DAWN OF QUADRUPEDS 



565 



Fig. 4. The Type of Mcrerpelon caudatum Moodie from the Carboniferous of Mazon 

 Crekk, Illinois. In the collection of the University of Chicago. Twice natural size. 



known to us. It is peculiar in the wide horn-like expansions of the 

 skull (Fig. 5). There is no pineal foramen in the dorsum of the skull 

 and it lacks a few of the characters of the other amphibians known 

 from this region. 



Interest in the early Amphibia has not slackened in the later years 

 and there have been many contributors to the knowledge of the early 

 forms. There are at present nearly seventy-five species of Carbonif- 

 erous Amphibia known from North America and as many have been 

 recorded from the Carboniferous and Permian of Europe; many more 

 undoubtedly await discovery. The forms do not differ greatly in their 

 structure in the two continents and each has relatively the same amphi- 

 bian fauna, although the North American fauna is perhaps somewhat 

 older than the European one. Certainly the Branchiosauria are found 



Fig. 5. A Skull of Diplocau'us magnicoraix Cope from the Permian of Texas. In the 

 collection of the University of Chicago. Three tenths natural size. 



