LACHNINiE. 



This section includes a number of insects, whicli 

 show sufficient peculiarities of structure to allow 

 a definite separation from the foregoing Aphidinae. 

 The few genera comprised in this group are perhaps 

 best typified by Illiger's old genus Laehnus, which fur- 

 nishes three very fine characteristic species, all of 

 which are inhabitants of the oak-tree. 



As to the wing-venation, the Lachnince do not much 

 depart from the species hitherto described in this 

 Monograph, but the positions and the curvatures of 

 the veins somewhat difi'er. The forking of the cubital 

 vein still obtains, but in the less developed species there 

 seems to be a tendency to the suppression of the 

 second oblique vein of the lower wings. This occurs 

 only in abnormal specimens. 



The antennae are reduced in length, and this is in 

 great measure caused by the loss of the seventh joint, 

 which is reduced to the condition of an elongated 

 button or papilla. 



