142 KANSAS UNIVERSITY SCIENCE BULLETIN. 



Since there is so little chitinization and thickening of the 

 membrane around the trachese of the hind wing, these can be 

 studied best in specimens such as the above, where air in the 

 tracheae renders them visible. This is especially true of the 

 costa, subcosta and vein in the anal fold. The subcosta cannot 

 be made out in the adult hind wing, and has not been figured 

 for it, but shows plainly when filled with air. By placing a 

 piece of black paper under the condenser of the microscope 

 the veins appear a glistening white, and under the low powers 

 are much more easily studied in this manner. 



An interesting point I observed in the hind wing was the 

 presence — in one specimen — of what should probably be re- 

 garded as a "sport" vein (26-2, sv) . It is connected with the 

 anal vein and also fuses with the costa. Since I have found in 

 one hind wing of two specimens, both male and female, the 

 radius forked, as is the case with the normal cubitus, which 

 branch, though a "sport," probably points back to a former 

 two-branched condition of that vein as seen in the fore wing, 

 this vein above mentioned may show the same condition for 

 the anal wing, and represent the second anal vein. I find 

 under "Psyllidse" in the "Zoological Record" for 1867 the fol- 

 lowing: "From the occurrence of irregularities in the vena- 

 tion of the wings of this species, [Amsosiro/j/m ficus Linn.] he 

 [Frauenfeld] takes occasion to remark upon the frequency of 

 such irregularities among the Psyllidse ; the variation is almost 

 always confined to one wing." 



Adult Venation. 



Fore Wing (27-6). — The costa can be easily traced around 

 the entire margin of the wing and is very thick at the basal 

 portion of the anterior edge. All the rest of the veins except 

 the anal arise from a single main trunk, which is the main 

 support for the wing. This trunk is composed of the three 

 tracheae mentioned above, fused — the subcosta plus radius, 

 media and cubitus. The subcosta and radius are fused as far 

 as the stigma, s, where the subcosta runs up toward the costal 

 margin, forms the lower margin of the stigma, and meets the 

 costa somewhat proximad of the apex of the wing. The radius 

 is composed of a single vein, probably representing R 4 -f 5. 

 At about the middle of the cell, /, a vein leaves the main trunk 

 which divides into two branches, each of these again dividing 

 once. The two upper branches represent M 1 -|- 2, and M 



