46 ENTOM 01.061 CAIv NEWS. [Feb.,'19 



derive the Mantids from Protoblattoid ancestors, and if this 

 be correct, it is very probable that the Blattids also are 

 descended from the same type of ancestor, and the Proto* 

 blattoids might be regarded as the forms connecting the Blat- 

 tids and Mantids with the ancestral Plecopteroid stock. The 

 Isopteron line of development does not follow that of the Blat- 

 tids quite as closely as the Mantids do, and I am not certain 

 whether the Isoptera branched off from the common Blattid- 

 Mantid stock at a point near the origin of this common stock, 

 or somewhere further along its path of development. There 

 is some reason for considering that the Isopteron line arose 

 rather near the base of this common stock, however, and I 

 would consider that the lack of fossil remains of Isoptera in 

 the earlier strata is again due to the incompleteness of the 

 palaeontological record rather than to the fact that the 

 Isoptera supposedly did not arise until a much later geolog- 

 ical period than the Blattids, as Handlirsch would maintain. 

 At any rate, the Isoptera have retained some very primitive 

 characters which occur among the lower representatives of the 

 Plecopteroid group, and their early or late geological appear- 

 ance cannot alter this fact ; so that the study of the ancestral 

 features occurring in the Isoptera and Mantids is extremely in- 

 structive for a phylogenetic comparison with the structures of 

 the Dermapteron and Embiid representatives of the Plecop- 

 teroid group, with which they have a surprisingly large num- 

 ber of features in common. The Isoptera, Mantidae and Blat- 

 tidae have been grouped in the superorder Panisoptcra and it 

 is possible that the fossil Protoblattoidea belong in this super- 

 order also ; but I would not group the Corrodentia, Mallophaga 

 and Siphunculata with them, as Handlirsch seems to do. The 

 Corrodentia with the Neuroptera appear to be an offshoot of 

 the Plecopteroid stock leading toward the Hemipteron line of 

 development, and as has been pointed out in several papers, the 

 Corrodentia, Mallophaga, Siphunculata (Anoplura), Thysan- 

 optera, Hemiptera and their allies constitute the superorder 

 Panhomoptera whose Hne of development parallels remarkably 

 closely that of the superorder Panneuroptera (composed of 

 the Neuroptera, Mecoptera, Diptera, Siphonaptera, Hymen- 



