:i4 THE STORY OF THE EARTH. 



pairs of stomata from the tracheae, which are 

 developed as in insects. True spiders arc found 

 in th measures of Bohemia, Silesia, and of 



Illin< 



Another representative of this group o{ Araeh- 

 nida is the scorpion, which is represented by the 

 genus Eoscorpius, Scorpions are first found in 

 the Silurian rocks. / rpius found in the coal 



i I Illinois, appears to be closely allied to a living 

 Californian scorpion, of the genus Buthus ; tho 

 the form found in the coal of this country agrees 

 best with the genus Scorpio, 



[nsects are well represented in the coal. 



Coleoptera arc* known from beetles named Cur- 



culioides and Troxites* Grasshoppers are found, 



kroaches. Lithomantis represents the 



living leaf-insect Mantis. The white ant occurs; 



ith a butterfly. Carboniferous insects are 



chiefly known from the coal-fields of the continent. 



The- fishes found in the coal measures include 

 a number of sharks, known from their fin defences 

 and teeth. 



Labyrinthodont reptilia ai red to more 



than twenty genera. Many of these arc from the 



Kilkenny coal-field, and Belgian coal-field. The 

 . . / nth ' a WUt US and / 



\ • humberland are among 

 the larj us genei a, I hej 



distinguished by having th< united to the 



jaw, w ith< iut being in - In s< >me families 



with a large bone in the 

 the para-sphenoid. The skull is 

 • 

 bones which a reptiles, 



I 



