✓ 
38 
AA. Honey tubes obsolete; antennae short with not over six distinct 
joints, seven being obsolete or represented by a very small unqui- 
culus attached to six. 
a. Front wings with three diseoidals, the third on e-bran ched; an¬ 
tenna? six-jointed, sixth longer than the fifth. 
b. Hind wings with two diseoidals; wings roofed. Eriosoma. 
bb. Hind wings with one discoidal; wings horizontal. Thelaxes. 
aa. Front wings with three simple diseoidals; hind wings with two 
diseoidals: 
b. Antennae six-jointed, sixth nearly as long as fourth and fifth to¬ 
gether. Pyrsocrypta. 
bb. Antennae six-jointed, four to six subequal, five a little the 
longest. Pemphigus. _ _ _ 
cutci. Front wings with two simple diseoidals; hind wings with 
one discoidal; antennae with four or five joints? Chermes. 
aa aa. Front wings with one one-branched discoidal ; antennae four 
or five-jointed? (three). Phylloxera. 
He further designates these ^genera by the parts of the plant they 
operate on and their habits thus : 
Aphis , foliage and roots. Calaphis , foliage. Callipterus , foliage. 
Lachnus , twigs. Eriosoma , twigs, limbs and roots. Thelaxes , galls. 
Pyrsocrypta , galls. Pemphigus , roots. Chermes , foliage. Phyllox¬ 
era , galls. 
The following synoptical tables which T have prepared, are intended 
simply as aids to readers and others desirous of tracing genera and 
species. 1 confess that to a certain extent they must be considered 
artificial, but this 1 find to be the case with all I have examined. 
Buckton’s arrangement is yet incomplete, and is wanting in reference 
to that portion of the family where the chief difficulty arises, reaching 
but partly through the Aphidium Passerini’s, the best complete 
synopsis we have, 1 consider defective in the following respects : It is 
based too exclusively on the number of joints in the antenme; it dis¬ 
tributes the root-feeding apterous species in different sub-families with 
out sufficient .grounds. The union of the SehizoneurincB with the- 
Pemphiginae is perhaps warranted in part by the similar habits of 
some of the species, but the marked distinction in the wing characters 
it seems to me justify the separation of the two groups at least as di¬ 
visions of a sub family if not as sub-families, as Buckton and Koch 
have done. It is evident that the two groups run into each other 
by such regular gradations that a rigid separation of the one troni the 
other would require the separation oi species of the same genus. . Ihe 
method I have adopted for the arrangements of these groups will be 
shown in the 'table of the sub-families. 
