LIST OF HOMOPTEROUS INSECTS. 945 



second fork and that of the fourth vein, but much less than the space 

 between the tip of the third vein and that of its first fork ; the second 

 vein diverges slightly from the third vein, and is a little nearer to it 

 at the base than at the tip, and its base is also a little nearer to the 

 third vein than it is to the first ; the distance between the tips of 

 the second and third veins is a little less than the space between the tip 

 of the third and that of its first fork, and a little more than half the 

 space between the first and second veins ; the space between the 

 first and second veins at the base is a little more than half of that 

 between them at the tips. 



a — r. England. (In Canada Balsam). From Mr. Walker's collec- 

 tion. 



16. Aphis Juglandicola. 



Lachnus Juglandicola, Kalt. Mon. Pflan. i. 151, 4. 



Aphis Juglandicola, Walk. Ann. Nat. Hist. Ser. 2, i.343, 15. 



The rib-vein is very slender, and nearly parallel to the fore 

 border of the wing, to which its approach and divergence afterwards 

 is veiy slight; there is no brand, but the vein forms a distiuct 

 though slight angle, and the space which it here encloses is rather 

 short and broad ; there is generally no fourth vein ; the length of the 

 third vein before the first fork is shorter than the space between the 

 forks, but longer than the second fork ; it is rather thick and quite dis- 

 tinct at its base ; the distance between the tips of the forks is about half 

 that between the tip of the third vein and that of its second fork ; the 

 second vein is straight, it diverges from the third, and the distance 

 between them at their tips is nearly twice that at the base ; the dis- 

 tance between the tip of the second vein and that of the third vein 

 is about equal to that between the latter and the tip of its first fork ; 

 along the rib-vein the first vein is farther by half from the second 

 than the second is from the third, and its distance from the second 

 at the tip is farther than that at the base by much more than half. 



In the female there are generally no traces of the fourth vein 

 of the wing, but in some instances it is quite distinct; it springs 

 from the angle of the rib-vein, and is slightly curved throughout its 

 length ; its tip is nearly as far from that of the rib-vein as it is from 

 the tip of the third vein. The dark colour of the oviparous female 

 seems to be owing to the eggs within it, these are three or four in 

 number. In the male there is a coloured space between the rib-vein 

 and the fore border ; the brand is darker towards the base, and the 

 fourth vein is distinct : it is more active than the males of the other 



PART IV. 3 O 



