GENERIC CLASSIFICATION OF APHIDIDAE. 75 
are more slender and of somewhat different proportions and the 
cubitus and anal of the fore wings are united somewhat at base. In 
other genera, however, this difference between species is to be found, 
and it seems wisest not to adopt it in this group as of generic im- 
portance. 
Characters. — Cornicles absent. Antennae of five segments armed, with linear or 
somewhat oval sensoiia. Fore wings with the media simple, the stigma normal; hind. 
wings with both media and cubitus present. Sexes unknown. Forms making galls 
upon the leaves of plants. 
Type (fixed by Matsumura, 1917), Nurudea ibofushi Mats. 
Genus PEMPHIGELLA Tullgren. 
1909. Pemphigella Tullgren, Arkiv for Zool., v. 5, p. 171. 
1918. Dasla Van der Goot, Mern. Ind. Mus., v. 6, p. 152. 
Characters. — Cornicles absent. Antennae of six segments armed with oval sensoria. 
Hind wings with both media and cubitus present. Sexes unknown. Species form- 
ing galls on plants. Type (monotypical), Tetraneura cornicularia Pass. 
Tribe PROCIPHILIM. 
The tribe Prociphilini contains forms which specialized in some direc- 
tions more than did the Eriosomatini. In other ways, however, they 
appear to be more primitive than certain genera of that tribe. The 
cornicles have here disappeared altogether and large wax areas have 
replaced them. In their habits of gall formation, however, the 
Eriosomatini are more advanced than are members of the present 
tribe. 
Characters. — Forms living in crumpled or twisted leaves or in a somewhat complete 
gall caused by the rolling up of the leaves of the host. Wax plates present; cornicles 
absent; antennae of stem mother of five segments; those of the alate form six segmented 
and armed with narrow, transverse, or somewhat broadly oval sensoria. 
Key to the Genera of the Pbociphilini. 
1. Media once forked, stem mother usually without wax plates Asiphum. 
Media simple, stem. mother with several rows of wax plates. 2. 
2. Wax plates large, those on the thorax well developed, stem mother and 
offspring living together. ....„.= 3. 
Wax plates not well developed, stem mother usually in a gall by herself . .Thecabius. 
3. Sensoria narrow, linear, ciliate Prociphilus. 
Sensoria somewhat oval, nonciliate Neoprociphilus. 
Genus ASIPHUM Koch. 
Plate XII, R-X. 
1857. Asiphum Koch, Die Pflanzenlause Aphiden, p. 246. 
1859. Type fixation, Gerstaecker, Bericht for 1857, p. 249. 
1905. Type fixation, Kirkaldy, Can. Ent., v. 37, p. 418. 
The genus Asiphum was erected by Koch with two species, populi 
Fab. and ligustrinellum Koch. He listed De Geer's work in the 
literature under populi Fab. The populi of Fabricius proves to be 
the tremulae of De Geer. Only the species ligustrinellum was placed 
