936 LIST OF HOMOPTEEOUS INSECTS. 



the tip of the fourth vein is to the tip of the rib-vein ; length of the 

 third vein before the first fork generally much longer, sometimes a 

 little shorter than its length between the forks ; distance between 

 the tip of the rib-vein and the tip of the fourth nearly twice that be- 

 tween the tip of the fourth and the tip of the third vein. 



Var. Angle of the rib-vein beneath the brand less obtuse, and 

 its outward side shorter in one wing than in the other. 



a — d. England. (In Canada Balsam). From Mr. Walker's collection. 



Group 2. Walk. Ann. Nat. Hist. Ser. 2, i. 255. 



3. Aphis Betul2e. 



Aphis Betulae, Linn. Syst. Nat. ii. 735, 21. Faun. Suee. 992. 



Bonnet, Hist. Nat. i. 3. Reaum. Ins. iii. pi. 22, f. 2. Deg. Ins. 



iii. 45, 3, f. 27, 28. Geoff. Ins. Par. i. 496, 7. Fabr. Sp. Ins. 



ii. 386, 20. Mant. Ins. ii. 316, 25. Ent. Syst. iv. 215, 25. 



Syst. Rhyn. 297, 25. Gmel. Ed. Syst. Nat. i. 4, 2206,21. 



Enc. Meth. Hist. Nat. Ins. pi. 1 16, f. 9. Schrank, Faun. Boic. 



ii. 1, 107, 1189. Berk. Syn. i. 120. Stew. El. Nat. Hist. ii. 110. 



Turt. Syst. Nat. ii. 705. Kalt. Mon. Pfian. i. 144, 118. 



Walk. Ann. Nat. Hist. Ser. 2, i. 255, 3. 

 Aphis nigritarsis, Hey den, Mus. Senhenburg, ii. Heft. 3, 299. 



Kalt. Mon. Pflan. i. 135, 103. Ratz. Forst. Ins. iii. 218, 20. 

 Aphis punctipennis ? Zetterstedt, Faun. Lapp. i. 559, 4. Ins. Lapp. 



ii.2,3ll,7. 

 Nigritarsifex, Amyot, Ann. Soc. Ent. Fr. 2me SSrie, v. 480. 



The viviparous winged female. This, before the end of March, 

 is nearly elliptical, plump, bristly, very dark green, or almost black 

 above, but paler beneath: six rows of tubercles along the back: 

 mouth reaching a little beyond the hind legs : feelers less than half 

 the length of the body : legs rather short and stout. As it increases 

 in size it becomes dark green, with the exception of the tubercles. 

 Fore-legs not much shorter than the hind-legs : rib slightly inclined 

 towards the fore-border at two-thirds of the length, and receding 

 from it beneath the brand, where it forms a distinct very long ob- 

 tuse angle; this begins very shortly after the middle of the fore bor- 

 der, is about one-third of the whole length of the wing, nearly linear, 

 except at the tip, where it forms a long acute angle ; first, second, 

 and third branch-veins obsolete before their source, especially the 

 third vein, whose first fork begins at a little before one-third of its 



