388 



ENTOMOLOGY 



has an alar expanse of twenty-eight inches. The Carbonife- 

 rous prototypes of our Odonata were gigantic beside their 

 modern descendants, one of them (Meganeura) having a spread 

 of over two feet ; they were more generalized in structure than 

 recent Odonata, presenting a much simpler type of neuration 

 and less differentiation of the segments of the thorax. The 

 Carboniferous precursors of our May flies attained a high 



FIG. 298. 



Lithomantis carbonarius, showing prothoracic appendages. Two thirds natural size. 



After WOODWARD. 



development in number and variety; in fact, the Ephemeridae, 

 like the Blattidae, achieved their maximum development ages 

 ago, when they attained an importance strongly contrasting 

 with their present meager representation. 



The Permian has supplied a remarkable genus Eugereon 

 (Fig. 299) with hemipterous mouth parts associated with fili- 

 form antennae and orthopteroid wings. The earliest unques- 

 tionable traces of insects with an indirect metamorphosis are 

 found in the Permian of Bohemia, in the shape of caddis worm 

 cases. 



Triassic. Triassic cockroaches present interesting stages 

 in the evolution of their family. Through these Mesozoic 



