PLATE XI. 
PERMIAN VERTEBRATA. SKULL OF ERYOPS 
Fras. 1-2. Eryops megacephalus Cope, 1878, side view of skull and lower jaw and under view 
of lower jaw, four sevenths natural size. Type specimen, Amer. Mus., No. 4189, 
Cope Coll. Lower Permian, Wichita basin, Texas. 

