62 5. W. WILLISTON 



amphibians is represented in the restoration of Cacops (Fig. 4), 

 as based upon a marvelously complete skeleton, one of a dozen or 

 more found associated with as many more of Varanosaurus and 

 Casea, shown in Figs. 9 and 10. This animal, twenty inches in length, 

 is one of a group of armored amphibians, very appositely called 

 by Cope ''batrachian armadillos," of which four or five genera are 

 known, nearly all of the animals of approximately the same size. 

 As suggested by Cope's name, they are all peculiarly characterized 

 by a carapace of bony plates over the back; in some almost com- 

 pletely covering it, in others like Cacops, forming only a narrow 

 row along the middle. In some of these has been found a peculiar 

 bony plate in the orbits which could only have been used as a pro- 

 tection for the eyeball, possibly an ossification of the nictitating 



Fig. 4. — Cacops aspidephorns, a stegocephalian amphibian twenty inches in 

 length. From Texas. 



membrane. And one genus has the head covered with small, 

 spiny excrescences. The ear, too, was conspicuously large, com- 

 pletely surrounded by bone in some, as shown. These amphibians, 

 like most of the other small ones, must have been chiefly insectivor- 

 ous, or invertebrate-feeding in habit, though the presence of stout 

 teeth on the palate suggests that any seizable living prey was accept- 

 able as food. They were all probably lowland animals, though 

 Trematops may have Hved more in the forests. Eryops, the largest 

 known, has a skull sometimes nearly two feet in length; other small 

 forms associated with it have skulls no larger than one's thumb 

 nail. Doubtless the lowlands in the vicinity of water in late 

 Pennsylvanian and early Permian times swarmed with these crea- 

 tures and with cotylosaurian reptiles of similar form and habits. 



