THE WINGS OF MEMBRACIDM 275 



the anterior trunk arise the costal, sub-costal, radial, and medial tracheae; 

 and from the posterior trunk, the cubital and anal tracheae. This condi- 

 tion exists in all Plecoptera that we have examined and in certain cock- 

 roaches, but had not been found elsewhere until observed by Funkhouser in 

 the Membracidae. A study of a long series of wings of many genera and 

 species of this family revealed only this condition; hence it is probably 

 characteristic of the family. 



Fig. 276. — The tracheation of the fore wing of a nymph of Thelia bimacidata (Based on 

 two figures by Funkhouser). 



In Figure 276, which represents the tracheation of the fore wing of a 

 nymph of Thelia bimaadata, the basal connection of the costo-radial group 

 of tracheae is well-shown ; and in Figure 277, which represents the fore wing 

 of a nymph of Ceresa horealis the basal connection of the cubito-anal group 

 of trachea is shown. The incompleteness of these and other figures of the 

 tracheation of the wings of nymphs is due to the fact that they are based on 



Fig. 277. — The tracheation of the fore wing of Ceresa borealis (After Funkhouser). 



