STATE HORTICULTURAL SOCIETY. 211 



a. Winged form obvious, or at least known. 



l>. Cubiial vein once forked or simple. — (3) Pemphigin.t:. 

 bh. Cubital vein twice forked. — (2) I.ACHNIN.K. 

 aa. Winged form unknown. — (4) RuizomiN/E. 

 .•\.\A. Antenna- five or only three-jointed. 



a. Winged form unknown. — (5) Tyciiein.E. 

 aa. Winged form obvious, or at least known. — (6) Chermessin/K, 



Tribe I. Aphidin.k. — Genera. 



A. Antennce on a frontal tubercle. 



a. Antenna; closely approximate at base, front grooved. — Siphonophora. 

 aa. Antenna.' remote at base, front flat or convex. 

 I). First joint of the antenna; with a tooth on the inside. — Phorodon. 

 bb. First joint of the antenna; not toothed. 



c. Nectaries or honey-tubes distinctly clavate. — Rhopalosiphwn. 



cc. Nectaries cylindrical, sometimes hardly attenuated at the base, more often 

 incrassated. 



d. Cubital vein twice forked. 



e. Tail much shorter than the nectaries. — Alyzus. 



ee. Tail longer than the nectaries, rarely equal to them in length. — Hyaloptert4S. 

 dd. Cubital vein once forked. — loxoptera. 

 AA. Antenna' not on a frontal tubercle. 



a. The seventh joint of the antenna; as long or longer than the sixth. 



b. Antenna^ smooth. 



c. Nectaries longer than thick, or if shorter, or none, then the wingless female 



has a smooth back. 



d. Nectaries cylindrical (very rarely none). — Aphis, 

 dd. Nectaries clavate. — Siphocorvne. 



cc. Nectaries shorter than thick, or if a little longer, then the wingless female 



has a hairy back. — Mysocallis. 

 bb. Antennce pilose. 



e. Nectaries cylindrical, or at least twice longer than thick. — Gladobius. 



ee. Nectaries tubercle shape, much shorter than thick, sometimes almost on a 



level with the surface. — Chaiiophorns. 

 aa. The seventh joint of the antenna' shorter than the sixth. 



f. Species atrial ; winged form elegant. — Plerocallis. 

 ff. Species subterranean ; winged form unknown. 



g. The third joint of the antenna' longer than the fourth; hind tarsi one- 



jointed. — Trama. 

 gg. Third joint of the antenna' as long as the fourth; hind tarsi two-jointed. — 

 Paracletus. 



Tribe II. Lachnin.^^;. 



.\. Sixth joint of the antenna; setaceous. — Sipha. 

 A.\. Sixth joint of the antenniv filiform or clavate, often ending in a spur, like a 

 rudimentary joint. 



a. Fourth vein of the fore wings nearly straight; stigma linear. — I.achnus. 

 aa. I'burth vein of the fore wings curved ; the stigma trapezoidal. 



b. Abdomen bare. 



c. Rostrum short, not extending to the middle legs. — Calliptcrus. 



cc. Rostrum more or less long, extending at least to the hind legs. — Ptero- 



chlorits. 

 bb. Abdomen woolly. — Phyllaphis. 



