DISTRIBUTION 



321 



become tegmina, with certain of the veins always blended together, 

 though the hind wings have retained their primitive characteristics with 

 a few modifications, such as the expansion of the anal area. Carbon- 

 iferous cockroaches furthermore exhibit ovipositors, straight, 'slender, 

 and half as long again as the abdomen organs which do not exist in 

 recent species. 



Lithomantis (Fig. 302), a remarkable form from Scotland, possessed 

 in addition to its four large neuropteroid wings, a pair of prothoracic 

 wing-like appendages which, provided they may be regarded as homolo- 

 gous with wings, represent a third pair, either atrophied or undeveloped 

 a condition which is never 

 found toclav, unless the 



ml < 



patagia of Lepidoptera rep- 

 resent wings, which is un- 

 likely. 



From the rich deposits 

 of Commentry, Brongniart 

 has described several forms 

 of striking interest. Dictyo- 

 neura is a Carboniferous 

 genus with neuropteroid 

 wings and an orthopteroid 

 body, having, in common 

 with several contemporary 

 genera, strong isopteran 

 affinities. Corydaloides 

 scudderi, a phasmid, has 

 an alar expanse of twentv- 



ric. 303. Lugereon oockingi. Ihree quarters natural 



eight inches. The Carbo- size. After DOHRX. 



niferous 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 neura- 

 tion and less differentiation of the segments of the thorax. The Carbonif- 

 erous precursors of our May flies attained a high development in number 

 and variety; in fact, the Ephemerida?, like the Blattida?, 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. 303) 

 with hemipterous mouth parts associated with filiform antenna? and 



22 



