■0 



(niDK TO THE FOSSIL MAMMALS AND BIRDS. 



Gallery of tootlied whales of the jNIiocene period differed from every 



Ceta_cea, (Jetaceaii now living, and approached more normal mammals 



ep . .^^ ^j^^ circumstance, that all their teeth were enamelled, 



while some of those at the back of the jaw were two-rooted. 



Instructive illustrations may be seen in plaster casts of skulls 



of Sqnakxlon (jratdovpi from the IMioccne of France and 



Fig. 6G. — Tympanic bone of Whalebone whale {Balaina pi-imigenia), from 

 the Red Crag of Suffolk ; one-half nat. size. 



FiG.GT. — Skull (A) and upper molar tooth (B) of Zenglodon 

 cetoides, from the Eocene of Alabama, U.S. A. ; A greatly 

 reduced, B one-fifth nat. size. 



Bavaria, and in an almost unique skull of Prosqualodon 

 australis from the Patagonian Formation of South America. 



The Miocene toothed-whales with enamelled two-rooted 

 teeth are especially interesting, because they connect the 

 modern simple -toothed ti'ibes with some whale-like creatures, 

 the Zeuglodonts, whidi a])i)ear to have flonrisheil in all seas 



