Vol. XXX] ENTOMOLOGICAL NEWS. 45 



of a higher type than the more prognathous one found in many 

 Isoptera, and the great extent of the compound eyes upward 

 toward the top of the head, which occurs in so many Blattids 

 should also be regarded as a more highly specialized condition. 

 The thickening of the fore wings to form tegmina indicates 

 another specialized condition in the Blattids, as does the ex- 

 tremely flattened condition of the body developed in connection 

 with their hiding habits. The asymmetrical development of 

 the genitalia of the males and the asymmetry of the cerci (in 

 regard to the number of segments composing them) and other 

 similar features would indicate that the Blattids are somewhat 

 more modified than the Isoptera in some respects ; although in 

 others, the Blattids are much more primitive than the Isoptera. 

 The Isoptera have preserved a number of features occurring 

 in the more primitive members of the group to which the 

 Plecoptera belong, such as the nature of the thoracic sclerites, 

 etc., which suggest that the Isoptera are even closer than the 

 Blattids are, to the very primitive Plecopteroid group ; so that 

 if we are to regard the Plecoptera as the nearest living rep- 

 resentatives of the ancestors of the other groups under dis- 

 cussion, it might be argued that the Isoptera are near the an- 

 cestral type connecting the Blattoid group with the Plecop- 

 teroid group. I am as yet unwilling to go to this extreme, 

 however, since I regard the lower Blattids as more primitive 

 than the lower Isoptera, taking their anatomy as a whole. The 

 fossil Protoblattoidea as reconstructed by Handlirsch cer- 

 tainly show a marked resemblance to certain members of the 

 group to which the Plecoptera belong, as well as to the 

 Palaeodictyoptera, and it is quite probable that these Pro- 

 toblattoidea more nearly represent the ancestral type leading 

 back to the Plecoptera-like forebears than the Isoptera do, 

 particularly since the Isoptera are quite highly specialized in 

 regard to many features in which the Blattids are decidedly 

 primitive. 



The Blattids and Mantids are extremely closely related, and 

 their lines of development soon merge in a common stock when 

 traced back toward their point of origin. Handlirsch would 



