40 
older authors were in the habit of describing them by simply stating 
the plant and part thereof they infested. As a general rule, those 
that reside on leaves select the under surface, doubtless for the pur¬ 
pose of avoiding the rays of the sun and of escaping the observation 
of birds and other enemies. It is also probable that the\ find the undei- 
side of the leaf more easily penetrated by their slender setae than the 
upper surface. , 
The genera into which this sub-family has been divided have been 
already "'mentioned in the preceding synoptical tables. 
There are three tolerably well marked sections in this sub-fanuly which 
it may be of advantage to notice before entering the descriptions of 
species, as' it will lessen the labor of assigning specimens to their 
proper genera and species. These divisions are biiefiy chaiactenzed 
m the preceding table. 
Section 1 . Siphonophorini. 
The species of this section do not present such striking differences 
in form or habits to those of Aphidini as to attract particular atten¬ 
tion upon a superficial examination, yet they are easily noticed by one 
who studies these insects somewhat carefully. 
The chief differences between the two are these: the presence of 
frontal tubercles on which the antennae are placed, which gives to the 
head when seen from the side, a somewhat peculiar appearance bear- 
slight resemblance to a goats head. 1 he antennae aie geneia i\ 
mg 
as°long and often considerably longer than the body. The size of 
the body is usually larger than in Aphidini , and the legs are also 
The honev-tubes in the large majority of the species are long, some¬ 
times equalling one-third the length of the body, dhe tail is also 
usually quite prominent. As a matter of course there are exceptions 
to most of these rules, but seldom if ever to more than one or two 
of them in the same species. The large majority of the species le- I 
side on the leaves of plants and mostly on those of a succulent nature, 
or on shrubs, few being found on trees, and m this case only on the 
The insects of this group evidently form the highest types of the 
family, and should therefore be placed at the head. 
*/ * 
Genus SIPHONOPHORA. Koch. 
Beak of moderate length; last joint almost as robust as the penulti¬ 
mate. An ten me seated on distinct frontal tubercles, very long slender 
and setaceous, at least as long as the whole body, and often^ winsidei- 
iblv longer extending in some instances to the tips of the closed 
wings. The two basal joints are short and thick; the third joint the 
longest, or at least longer than the fourth, tilth, or >i. t , 
sometimes longer than the fourth and fifth ,.l e T£e 
usually shorter than the preceding one; the seventh bustle 1 , 
much 'longer than the sixth and sometimes as long or slightly longer 
than the third. The frontal tubercles, on which the antennae stand 
approximate each other, giving to the front of the head the appearance 
. ..<ir,» W— ■ 
