70 SEVENTEENTH Report STATE ENTOMOLOGIST OF MINNESoTA—1918 
16. TrinE SCHIZONEURINI 
Kkoeh, 1854, Die Pflanzenl. Heft 1. Sub Schizoneuriden (tribe). 
Thomas, 1879, Report 8. Sub Schizoneurini (section). 
Mordwilko, 1908, Acad. Imper. Vol. 138. Sub Schizoneurina (group). 
The tribe is essentially the same as the group as treated by various 
authors. The recognition of the tribe followed from an attempt to clear 
up the close relationship found between the Schizoneurina and Pem- 
phigina, associating the Prociphilini as a tribe with the Schizoneurina. 
Morphological characters. The distinguishing characters of the 
tribe are the absence of gland areas on the head, and the arrangement 
of the large facets of the areas in a ring around a central area; the 
annuli of the antennae usually form complete rings; media usually 
one-branched. 
Biological characters. The favorite food habitat for hibernation 
and early spring generations seems to be Ulmus. 
17. TRipE PROCIPHILINI 
Koch, 1854, Die Pflanzenl. Heft 1. Sub Prociphiliden (tribe). 
Koch (1854) considers that Prociphilus represents a distinct 
tribe which is placed between the Schizoneurini and Pemphigini. 
There are some reasons for this. The type genus at present is con- 
sidered by most writers under the Pemphigini. In general appearance 
and habitat it is a Schizoneurina, in venation it shows close affinities 
to the Pemphigina. 
Morphological characters. The distinguishing characters are the 
presence of obvious gland areas on the head and thorax as well as on 
the abdomen, which appears as a distinct line of development from 
those of Schizoneurini and Pemphigina. Media is simple and the 
venation of the hind wings is triradiate as in the Pemphigini. 
Biological characters. The principal food habitat for hibernation 
and the spring generations is Fraxinus. 
IX. Group PEMPHIGINA 
Hartig, 1837, Jahresb. Vol. 1. Sub Pemphigus (genus). 
Koch, 1854, Die Pflanzenl. Heft 1. Sub Pemphigiden (tribe). 
Thomas, 1879, Report 8. Sub Pemphigini (section). 
Buckton, 1881, Monogr. Vol. 38. Sub Pemphiginae (tribe). 
Mordwilko, 1908, Acad. Imper. Vol. 18. Sub Pemphigina (group). 
Hartig (1837) proposed the first genus that has given the name 
to the group as well as the subfamily. Koch (1854) first named the 
tribe Pemphigiden which is a nomen nudum. Thomas (1879) gave 
