594 



ARTHROPODA. 



the body, but in which the wings have the characteristic features of 

 those of the Palceodictyoptera generally, being equally developed, 

 with a simple neuration, the anterior pair being unthickened and 

 transparent. The two best known genera of this group are Titano- 





■ N F ,< -y -^*- 



Fig. 444. — Haplophlcbium Baruesiz (after Dawson). From the Carboniferous rocks 

 of Canada, a, Profile of base of wing. 



phasma and Protophasma, both from the Carboniferous rocks. The 

 same formation has also yielded a number of other allied types, 

 upon which have been founded the genera Dictyoneura, Haplophle- 

 bium (fig. 444), Pao/ia, Breyeria, &c. 



The Neuropteroid section of the Palczodictyoptera includes a num- 

 ber of Palaeozoic insects, which 

 appear upon the whole to be 

 most nearly allied to the existing 

 May - flies (Epkemeridce). The 

 most ancient types of this section 

 appear in the Upper Devonian 

 rocks of Canada, and upon these 

 have been founded the genera 

 Platephemera (fig. 445), Homothe- 

 fus, Xeno?ieura, and Lithentomum. 

 A number of allied types, which 

 have been referred to such genera 

 as Miamia, Lithomantis, JETemeristia, &c, have been detected in the 

 Coal-measures of both Europe and North America. 



Of the Hemipteroid section of the Palceodictyoptera the most 

 remarkable type is the Permian genus Eugereon (fig. 446). In this 

 remarkable genus the mouth-organs are lancet-shaped, the antennae 

 are slender and many-jointed, and the front and hind wings are 



Fig. 445. — Wing of Platephemera antiqua, 

 from the Upper Devonian rocks of Canada. 

 (After Dawson.) 



