PLATE III. 



This plate illustrates the relative positions of the veiDS in the subfamilies of 

 the Aphididie; and in addition is explained the nomenclature bearing on this 

 subject as used in the text. 



Figure 18. 



Subfamily Lachnina?. Lachnus lonfjistigma. 



This is the largest wing in the entire family. Another special feature is the 



extent of the stima and stigmal cell proper, which in the stigma is distinctly 



bounded distally at A, while the stigmatic coloration extends around to the 



apical margin, I. 



Figure 19. 

 Subfamily Aphidina?. Aphis brassicce. 

 A is the front or cephalic wing, B is the caudal or hind wing. These letters 

 also represent the wing insertions. In the following the same letters apply to 

 each wing: 



A. — Costal cell. 



B.— Basal cell. 



C — First discoidal cell. 



D. — Second discoidal cell. 



E.— First cubital cell. 



F. — Second cubital cell. 



G. — Inframarginal cell. 



H. — Marginal or stigmal cell. 



I.— Apical margin or apex. 



G and H are also known as apical cells. 



1. — Costa or costal vein. 



2. — Subcostal vein or cubitus. 



3. — First discoidal vein. 



4. — Second discoidal vein. 



5. — Third discoidal vein. 



6. — Second branch. 



7. — First branch. 



8. — Stigmatic vein. 



9. — Stigma. 

 10.— Fold for hooklet. 

 11.— Hooklet. 



Figure 20. 

 Subfamily Schizoneurinse, Sohizoneura lanigera. 



The points A and B are the points from which the measurements of breadth 

 are taken, and the letters C and D the points from which the measurement of 

 length of the stigma is taken. 



Figure 21. 

 Subfamily Pemphiginie. Pemi)higus i^ojiulitransversus. 



Figure 22. 

 Subfamily Chermisinae. Phylloxera. 



Figures 23 and 24. 

 Subfamily Aphidicie. * 



These figures illustrate some of the anomalous venation that is frequently 

 found in the genus CaWpterus. The drawing is taken from the wings of Cal- 

 liptcrus genevei. 



