xxxii. '21] ENTOMOLOGICAL N'KXVS 101 



of the wings of the Zoraptera is suitable only for tracing the 

 development of the oligoneurous tendencies of the Homoptera 

 and other derived forms, while a study of the polyneurous 

 types of Neuroptera would be of more value for tracing the 

 origin of the tendency toward the development of polyneurous 

 types of venation in certain Homoptera. In the present paper, 

 how-ever, I have concerned myself only with the oligoneurous 

 tendencies, since it is better to discuss onlv one tendency at a 

 time, and the chief aim of this paper is to point out the posi- 

 tion of the Zoraptera, which are oligoneurous forms, in the 

 developmental scale of the higher insects. 



The contour of the head capsule, the character of the 

 thoracic sclerites (especially the thoracic terga), the terminal 

 abdominal segments and certain of the internal organs, such 

 as the tightly coiled testes of the male, clearly indicate a very 

 close relationship between the Zoraptera and the Psocida. It 

 is, therefore, rather disappointing,* to find that the wings of 

 the Zoraptera do not resemble those of the Psocida which I 

 have -been able to examine more strikingly than they do 

 although there is an undeniable resemblance between the wing 

 of the Zorapteron shown in Fig. 5 and that of the Psocid 

 shown in Fig. 8 in the character of the pterostigma (i. e. the 

 stippled area in the two figures) and the tendency for the 

 parts of the vein Rs to move toward Rl. The same resem- 

 blance is traceable in the Homopteron shown in Fig. 6, since 

 the vein Rs is unbranched in this insect, and approaches Rl 

 near the tip of the pterostigma, or stipple-! area, as in Fig. 5. 



The Homopteron shown in Fig. 6 is strikingly similar to 

 the Psocid shown in Fig. 8 in the character of the anal veins, 

 the two-branched C'n and ,17. and in the development of a 

 pterostigma (stippled area) ; and the evidence of a close rela- 

 tionship between the Psyllids (Homoptera) and the Psocids 

 drawn from other sources fully continii of the wing 



venation. I would therefore maintain that the Psyllid Homop- 

 tera and the Psocida are very closely n iled, and were de- 



* The resemblance of both fore and hind wind's of the P.M>rid .Irclii- 

 /'sucus text or to the wings of the Zoraptera is strikingly cl< >-,., ;t ^ has 

 been pointed out in a paper to be published in the Canadian I:nti>- 

 mologist. 



