12-i 



University of California Publications. [Entomology 



The hind wings are never as peculiar as those of the Heter- 

 optera, but resemble quite closely the front wings. Neverthe- 

 less, one can readily trace in the hind wing of Fulgorida?, 

 which clearly represent the most primitive group among the 

 Homoptera, all the veins of a heteropterous wing. We may 

 conclude, therefore, that the hind wing of most of the families 

 of Homoptera have more nearly kept pace with the front wings 

 in their specialization than have those of the Heteroptera. 



In the matter of the homology between the front and hind 

 wing, Comstock and Needham have clearly made a mistake. 

 There are three less cells in the hind wing of Cicada than in 

 the front wing, and the missing three are the apical ones. 

 These authors and Redtenbacher place their vein VII one vein 

 too far forward, as they have consistently done throughout' 

 this order and in the Orthoptera. 



PHYTOPHTHIRES. 



The four families constituting this group possess very simple 

 venations, which are quite different in the several families. In 

 only the Psyllida? is the venation extensive enough to show 



clearly their affinity to the 

 higher Homoptera. The small 

 size of all these insects is 

 probably accountable for the 

 simplicity ,of their venation. 

 The venation in the Psyl- 

 lida^ is shown in Fig. 62. The 

 largest part of the area of the 

 wing is occupied by the incle- 

 T.^n--/'^- l*-''^'' w.°VV'' ''®"^*t\?" ^'iV^'.'i pendents, which appear as a 



Psyllidie. Fuie dotted line is the claval r > i i 



fold; the other dotted lines represent veins twice-forked branch from the 



tliat are sometimes absent. 



primary. The marginal ex- 

 tends all around the wing and there is but one posterior. 



The Aphida^ differ from the Psyllida? by the suppression of 

 the posteriors, and by some differences in the attachments of 

 the independents, as shown in the accompanying diagram 

 (Fig. 63). The hind wing is more reduced than in the Psyllida, 

 and its maximum venation is nearly the same as the minimum 

 of the front wing. The additional independent and the cross 

 vein at the tip are very rarely present. 



The Aleurodida^ exhibit a still further reduction. The front 



