CHAPTER VI 



EXTINCT FISHES BELEMNITES LINGULA — 



TRILOBITES — SCORPIONS AND STONE LILIES 



WE might, if we had time, now look at the 

 remains of the great bony Labyrintho- 

 donts — creatures aUied to the newts, salaman- 

 ders and frogs of to-day, which form the class 

 Amphibia. They stand lower than the Rsptiles, 

 Birds and Mammals ; and though they have 

 typically five toes and crawl or walk the earth, 

 yet are essentially aquatic animals, inasmuch as 

 their young are " tadpoles," fish-like in form 

 and provided with gills. No reptile, bird or 

 mammal has hitherto been found in what are 

 called the Palaeozoic strata, but in the Upper 

 Palaeozoic strata — ^those of the Carboniferous 

 system, the period of the coal-bearing strata 

 (see Table of Strata) — there was an immense 



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