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ENTOMOLOGY 



These Devonian forms attained huge dimensions as compared with their 

 recent representatives; Gerephemera, for example, had an estimated ex- 

 panse of 175 millimeters. 



Carboniferous. The Carboniferous age, with its luxuriant vegeta- 

 tion, is marked by the appearance of insects in great number and variety, 



FIG. 300. Xenoneura anti-quorum^ five times natural size. After SCUDDER. 



still restricted, however, to the more generalized orders. The domi- 

 nance of cockroaches in the Carboniferous is especially noteworthy, no 

 less than 200 Palaeozoic species being known from Europe and North 



FIG. 301. Etoblattina ma- 

 zona, a Carboniferous cock- 

 roach from Illinois. Twice 

 natural size. After SCUDDER 

 in Mi all and Denny. 



FIG. 302. Lithomantis carbonarius, showing protho- 

 racic appendages. Two thirds natural size. After WOOD- 

 WARD. 



America. These ancient roaches (Fig. 301) differed from their modern 

 descendants in the similarity of the two pairs of wings, which were alike 

 in form, size, transparency and general neuration, with six principal 

 nervures in each wing; while in recent cockroaches the front wings have 



