76 



PALAEONTOLOGY 



assemblage of Ortliopteroid forms ancestral to some of the existing 

 cmsorial and saltatorial groups. It is an early offshoot of the 

 Pakeodictyoptera, whose members retain many of the venational 

 characteristics of the latter, but are distinguished by the following 

 features. The pro thoracic notal expansions, so prominent among 

 Palfeodictyoptera, are present in certain forms only ; the prothorax 



Fig. .'J7. Dieconeura arcuatu Scud. 

 (After Handlirsch.) 



restoration. 



is more specialised, lacing markedly elongated in some forms and 

 broader and more shield-like in others. The hind wings are 

 broader than the fore wings, owing largely to the development of 

 a fan-like anal lobe (Fig. 37). The venation resembles that of the 

 more specialised of the PalcCodictyo]:)tera, the median vein exhibits 

 the branches MA and MP and the primitive archedictyon is 

 retained. Handlirsch's order Protoblattoidea (Fig. 37) which 

 comprises ancestral cockroach-like forms does not appear to merit 



