LIST OF HOMOPTEROUS INSECTS. 941 



Group 7. Walk. Ann. Nat. Hist. Ser. 2, i. 333. 



9. Aphis Betulicola. 



Aphis Betulicola, Kalt. Man. Pflan. i. 44. Ratz. Forst. Ins. iii. 

 216, 2. Walk. Ann. Nat. Hist. Ser. 2, i. 333, 9. 



The rib-vein slightly approaches the fore border before it re- 

 cedes from it and incloses the brand ; its angle is at three-fourths of 

 the length of the brand, and though very obtuse is more decided 

 than in many other species ; the fourth vein is much curved through- 

 out its length ; its tip only is usually apparent, and is a little nearer 

 to the tip of the rib-vein than to the tip of the third vein ; the 

 third vein springs from the rib-vein, a very little before the latter 

 recedes from the fore border, the space between the first and the 

 second forks shorter than the third fork, and much shorter than 

 the third vein before the first fork ; it forms two distinct angles 

 when it emits the forks ; its distance along the rib- vein from the 

 fourth vein, is very nearly twice that from the second ; the tip 

 of the second fork is a very little nearer to the tip of the fourth 

 vein than to the tip of the first fork ; the tip of the first fork is 

 nearer to the tip of the second than to the tip of the third vein, 

 and the latter is a little nearer to the tip of the first fork, than 

 to the tip of the second vein ; the second vein is nearly straight, 

 and diverges slightly from the third, and its distance from the 

 latter at the tip is farther by half than at the base; its distance 

 at the base from the third vein is a little less than that from the 

 first vein at the base, but much less at the tip ; the first vein di- 

 verges considerably from the second, and is almost perpendicular 

 to the rib-vein ; its distance on the rib-vein from the second vein 

 is much less than half its distance from the base of the wing, 

 but at the tip it is much more than the above proportion ; the 

 distance between these veins at the base is much less than half 

 that at their tips: the legs are long and slender, the hind-legs 

 rather longer than the rest, their shanks slightly curved : there is 

 an appendage on each side of the first joint of the feelers. 



Var. The second part of the third vein is longer than the 

 first or the second. 



Var. No second fork in one wing ; in the other wing no 

 first vein ; its second vein is forked, but both the branches cease 

 before they attain the hind border ; the third vein has no fork, 

 and also comes short of the usual length. 



