FOSSIL ORDERS 



75 



irregular network, or archedictyon, of fine veinlets over the 

 whole wing membrane (Fig. 36). The abdomen is elongate and 

 10-segmented, each segment often with conspicuous side-lobes of 

 a similar nature to those of the prothorax, although much less 

 pronounced. At the apex of the abdomen is a pair of slender and 

 often greatly elongated cerci, and, in some genera, a median caudal 

 filament is also present. 



The order is almost exclusively confmed to the lower and 

 middle strata of the Upper Carboniferous, and about 160 species 



Fig. 36. Stenodictya lohata Brongn., restoration. (After Handlirsch.) 



are known. It appears to have declined comparatively abruptly, 

 since there are very few representatives in the later Carboniferous 

 and Permian rocks. Handlirsch (1925) recognises twenty-four 

 families, and among the more important genera are the following : 

 Stenodictya Brongn. (Fig. 36), Commentry (France) ; Stilbocrocis 

 Handl., Germany ; Mecynoptera Handl., Belgium ; Lithomantis 

 Woodward, Scotland; Homoloptera Brongn., Commentry (France); 

 Homaloneura Brongn., Commentry (France) ; Styne Handl., 

 Germany ; D unbar ia Till., Kansas ; and many others. 



Protorthoptera Handl. This order comprises a miscellaneous 



