434 
CLASS VIII. 
By far the greatest number of species live above ground on branches 
and leaves. Amongst these both winged and wingless individuals occur in 
the same species. The winged individuals have constantly three simple 
eyes (KALTENBACH). 
a) Wings horizontal. Abdomen without cornicles or tubercles, (An- 
tenn short. ) 
Phylloxera Boyer De Fonsc., Hartic. Antenne triarticulate, 
with last joint fusiform, elongate, emarginate, obscurely annulate. 
Anterior wings with cubital nerve undivided. 
Vacuna V. HeypeN, Kaurens. Antenne five-jointed. Anterior 
wings with cubital nerve bifid. 
b) Wings deflected, obliquely erect above the body. 
* Cubital nerve undivided. 
Phleopthiridium mihi, Chermes Hartic. (Species from genus 
Chermes L.) Antenne short, thickish, filiform, with five joints. Feet 
short. Abdomen without cornicles. 
Note.—Chermes is a name by no means to be given to the modern genus, 
which rejecting all the other Linnean species, contains one alone (C. 
Abietis); the diagnosis of Linnmus himself teaches this. On this and 
other allied species comp. especially RATzEBURG, Forst-Ins. TI. pp. 195— 
205, Tab. x11. These insects appear to be oviparous alone ; copulation 
has not yet been seen. 
Pemphigus Hartic. (Spec. Chermes Burm.) 
Tetranewra Hartic. (Antenne with six joints.) 
* Cubital nerve sending off one or two branches. 
Schizonewra Hartic, Karrens., Myzoxylus Biot (Lriosoma 
Leacu, in part). Cubital nerve bifid. Antenne short, sex-articulate. 
Cornicles of abdomen none or obsolete. 
Sp. Aphis lanigera Hausmann, Hriosoma mali Lracu, &e. 
Lachnus Ii11e., Burm. Cubital nerve trifid. Antenne sex-articu- 
late, shorter than body. Feet long. Short tubercles alone in 
abdomen, in place of cornicles. Feet, especially the posterior, long. 
Rostrum sometimes very long. 
Sp. Lachnus fagi, Aphis fagi L., Réaum. Ins. 111. Pl. 26, figs. 1—6. The 
abdomen of this species }’” in size is covered with very long white wool ; 
it looks like a bit of white flue ; this species is very often seen on beeches 
in the groves at the Hague. 
Aphis T11¢., Burm. Cubital nerve bifid. Antenne sept-articulate, 
longer than body. Feet long. Abdomen with two cornicles. 
