GENERIC CLASSIFICATION' OF APHIDIDAE. 81 
Characters. — Cornicles wanting; apterous form usually with five-segmented antennae 
and eyes of three facets. With the intermediate forms more facets may occur. Alate 
form with usually six-segmented antennae and rather large oval sensoria with distinct 
rims. Fore wings with media simple. Hind wings with both media and cubitus 
present, though these may be faint and almost obscured in balsam. Cauda large 
and somewhat rectangular or rounded. Subterranean forms living on the roots of 
plants. Sexes small, apterous, and beakless. 
Type (monotypical), Geoica squamosa Hart. 
Genus PARACLETUS Heyden. 
Plate XIV, L-S. 
1837. Paracletus Heyden, Mus. Sinkbg., v. 2, p. 295. 
The genus Paracletus is closely related to Forda Heyden from which 
it may be distinguished by the number of antennal segments in both 
alate and apterous forms. As with other genera of this tribe the eyes 
of the apterous form consist of three facets. Intermediate forms 
often occur, however, in which the intermediate nature is indicated 
only by the eyes which have the beginnings of compound eyes, such 
as are found in the alate form. There never are, however, complete 
compound eyes. The genus was erected by Heyden in 1837. The 
species live in close association with ants. 
Characters. — Cornicles absent. Apterous form with six-segmented antennae and 
eyes of three facets; alate form with six-segmented antennae which possess many 
rather small, oval sensoria. Fore wings with media simple, hind wings with both media 
and cubitus present, arising some distance apart. Thorax with a central wax plate. 
Forms living in the nest of ants and cared for by them. Sexes small, apterous, and 
beakless. In some cases only one claw is met with on the foot, while in other cases 
the normal number of two is present. This appears to be no definite character, as 
sometimes a claw is dropped from one foot and sometimes from another. 
Type (monotypical), Paracletus cimiciformis Heyden. 
Subfamily IV, HORM APHIDINAE. 
The genera placed in this subfamily have usually been placed 
with the Eriosomatinae, or Pemphiginae, as it has been sometimes 
called. Mordwilko, however, placed these forms as his third tribe 
under the subfamily Aphidinae next to his tribe Callipterea. 
Something can be said in favor of both of these placings. In 
the first instance, the species in general form, antennal structure, 
and habit of gall formation are no doubt suggestive of the 
Eriosomatinae. On the other hand, their structure in regard to 
cauda and anal plate is very like the Callipterina and the sexual 
forms appear to have a development of their own, although they 
are nearer in many ways to the Aphidinae than to the Eriosomatinae. 
It is the author's belief that these forms should constitute a sepa- 
rate subfamily. It has developed the habit of gall formation 
and the sensory characters which usually accompany it, while at 
the same time it has retained in the sexual female the normal develop- 
141613°— 20— Bull. 826 6 
