115 
None of the species have, so far as I am aware, ever been found 
doing any considerable injury to useful or ornamental trees in this 
country. 
The section is a limited one as at present restricted, containing but 
two or three represented genera, and but few species. 
Genus LACHNUS. Illiger. 
This genus is closely related to the preceding one; as in it, the 
front wings have the third discoidal vein twice forked, but the stigma 
is more of a linear shape, being longer and narrower; and the fourth, 
or stigmatic vein nearly straight or but slightly curved; the posterior 
wings have two branch veins. The auteunae are usually short, extend¬ 
ing but little beyond, and often not to, the middle of the body, but 
slightly tapering; the sixth joint is usually or perhaps always furn¬ 
ished with a little spur at the tip, which is shorter than the sixth 
joint and often minute. The head is small and the prothorax narrow; 
the abdomen is rather more than usually broad, especially posteriorly. 
The beak long and rather slender, extending to, and even beyond, the 
posterior coxae. The honey-tubes are reduced to mere tubercles, and 
sometimes almost obsolete. The colors are generally somber, dull 
red, brown and black prevailing. Dr. LeBaron was of the opinion 
that, as a rule, the abdomen is marked by transverse rows of dots; 
but there are too many exceptions to consider this a rule. 
Although often found on the branches of trees, they are by no 
means confined to these, as they frequently occur on the leaves; but 
as a very general rule they reside on trees. 
Lachnus salicicola, IThler. The Plant-louse of the Willow. 
This is the A. salicti of Harris, but as this specific name had al¬ 
ready been given by Schrank to a European species infesting the wil¬ 
low, Uhler changed it to the name we have here given. It is evident¬ 
ly very closely allied to the following, yet appears to be distinct. It 
is a large species, although smaller than L. dent at us, and lives on the 
branches and twigs of various kinds of willows, clustering together on 
the under side, often in great numbers. The winged individuals ap- 
