34 THE UNIVERSITY SCIENCE BULLETIN. 



others having two or none, would indicate their more primi- 

 tive condition. 



It is quite commonly believed also by Homopterists that the 

 Fulgoridse represent the most specialized forms of this group. 

 This opinion was held by Kirkaldy and Hansen and is held to- 

 day by Funkhouser and others. One cannot look carefully at 

 the wonderful antennae of a large number of these forms with- 

 out agreeing with this disposition of the family provided the 

 development of the antennas and its sensory organs be consid- 

 ered an important criterion. Certain it is that they must be 

 placed by themselves, for it would be hard to try to connect 

 them closely with any of the four other families of the group. 



The three families, Membracidse, Cicadellidse, and Cercopidx 

 are now left for consideration. One cannot have even a casual 

 acquaintance with these forms without realizing their sim- 

 ilarity and close affinity. That they are all three derived from 

 a common stem seems to be plainly evident. The question is as 

 to their relative position. 



Having made the Cicadidse the lowest and the Fulgoridse the 

 highest families of the Auchenorhynchi, we must necessarily 

 place the remaining families in between, so that we now have 

 the Cicadidse arising from a lower stem, the Membracidae, Cicci- 

 dellidse, and Cercopidse from a middle one, and the Fulgoridse 

 from a third and highest one. 



When we study the families arising from this middle stem it 

 seems that Funkhouser has made his point in claiming that the 

 Membracidse are the lowest of the three. This would put them 

 next to the Cicadidse, but as we have indicated, their relation- 

 ship would not be so much with them as with the other families 

 of the middle stem. In support of his position he shows that 

 the Membracidse have a very poorly developed sensory system, 

 causing them to respond very slowly to stimuli, that the wings 

 are very generalized, and that the genital organs are simple. 

 In the first, if not in all of these respects, the Cicadellidse and 

 Cercopidse are certainly more specialized. 



The question now arises as to which of these two families is 

 closer to the Membracidse. Here we are helped by a curious 

 insect which seems to be half Membracid and half Cicadellid. 

 I refer to ^thalion, an insect found in this country and in 

 Central and South America. It looks very much like a Cica- 

 dellid, but instead of having a double row of prominent spines 



