PHYLOGENY 



95 



undoubtedly a good deal of intergrading among different groups 

 wherein differentiation has not proceeded very far, and many 

 forms which have to be regarded as of generic status display 

 characters which would be classed as of family, or higher, 

 significance, among recent forms. 



The Protorthoptera exhibit definite advance on the 

 Palaeodictyoptera ; for example, the structure of their thorax 

 indicates that they had developed some capacity for running, 

 whereas the ancestral order probably had feeble powers of 

 terrestrial locomotion and resorted to short spontaneous flights. 

 These early Orthopteroid forms show increased development of 

 the hind wings, and the expanded anal area of those organs is a 



Cu, lA *,♦, 



Fig. 46. ' A, Brodia priscotincta Scud, wing (58 mm. long), with 

 cross- veins omitted. B, Kennedya rnirabilis Till, wing (44 mm. 

 long). (Adapted from Tillyard, Rec. Ind. Mus., XXX., 1928.) 



distinct advance upon the closely similar fore and hind wings of 

 the Palaeodictyoptera. The Protoblattoidea were early cockroach- 

 like forms which connected the Protorthoptera with the true 

 Blattidge that co-existed with them. Other of the Protorthoptera 

 exhibit modifications in different directions, and (Edischia Brongn., 

 for example, has the unmistakable facies of a primordial long- 

 horned grasshopper. Some of tKe Protorthopterans carried 

 pronotal expansions and thereby resembled the Palaeodictyoptera. 

 The presence of these expansions, however, is sometimes coupled 

 with evidences of an ovipositor — an organ which is not developed 

 in the Palaeodictyoptera. 



The Megasecoptera were an evidently specialised order : the 

 narrowing of their wing-bases and the reduction of their venation 



