8 A Period in tie History of our Planet, 



qiiiry demonstrated them to be Crustacea similar to the Aselli 

 and Ijimuli, but whose type, no longer preserved, makes way 

 for other and more highly developed forms. 



Strangely formed fishes, armed with hard bony scales against 

 the attacks of their own species, lived and moved amidst the 

 hot waters of the greywacke ; and it is remarkable that all 

 the^shes of the greywacke and coal formations belong to the 

 Placoidians (Rays and Sharks), and to the strange looking 

 Ganoidians, whose vertebral column, bent upwards in the caudal 

 fin, presents a configuration impressed upon the full-grown fish 

 which, at the present day, amongst bony fishes, is found only 

 in embryos, and the structure of whose teeth distinctly shows 

 that they lived principally upon hard mollusca, which they 

 crushed with their flat teeth, or on the putrid remains of plants 

 and mollusca. Many of these remarkable fishes, and espe- 

 cially some from the old red sandstone, have, from the uncom- 

 mon prolongation of the articulated coverings of their gills, 

 been described and delineated as insects, as water-beetles. 



In the first creation, then, was formed the germ of the ver- 

 tebrated animals, that fourth division in the domain of the 

 animal economy, which was afterwards to receive in man its 

 highest development. 



The gigantic ferns and monocotyledones, the remains of 

 which at the present day afibrd, in the shape of coal, the most 

 powerful lever of human civilization, covered the dry land. 

 They displayed little variety of form ; but if the species were 

 not numerous, and if their type was limited, the want of va- 

 riety was made up for by the large quantity of the indivi- 

 duals. 



This first creation vanished away ; its animal remains w^ere 

 entombed in the stony strata that were deposited at the bot- 

 tom of the waters ; its forests were sunk and covered in the 

 abysses. Separate islands rose above the surface of the wa- 

 ters ; previously existing ones became larger ; the dry land in- 

 creased in extent. And beside the Ganoidians of the Mansfeld 

 elate, and the other curious fishes of the variegated sandstone 

 and the muschelkalk, whose jaw-bones some have even ascribed 

 to Mammalia, beside these obscure organisms, there lived huge 



