128 



THE CHAIN OF LIFE. 



also had enemies to be dreaded. These plates serve to ally 

 them with the Ganoids, as their jaws do with Lepidosiren. 



We are thus enabled to see in the streams, lakes, and bays 

 of the Palaeozoic, harmless fishes, of the type of Ceratodus, 

 feeding on plants, and huge precursors of the Mud-fishes 



Y 



J ^ 



y 



Fig. 114. 'Lov.'tr }2iW oi Dinichihys Ilefizcri One-sixth natural size. 



darting from the depths, and provided with a dental apparatus 

 more formidable than that of any modern fi^" , sufficient to 

 pierce the strongest armour of the Ganoids, and to destroy and 

 devour the largest aquatic animals. These huge fishes, armed 

 with shears two or three feet in length, and capable of cutting 



Fig. 115. — Jaws of Lepidosiren. Natural size. — After NewL err j'. 



asunder scale, flesh, and bone, are the beau ideal of destructive 

 monsters of the deep, far surpassing our modern Sharks ; and 

 if, by means of supplementary lungs, they could breathe in air 

 as well as in water, they would on that account be all the more 

 vigorous and voracious. 



