1923] The Fulgorid.e of Eastern North America 145 



Issince. That this is not determined by environment would seem to 

 be settled by the fact that brachypteroiis and macropteroiis forms, or 

 koelopterous and macropterous forms of the same species occur on the 

 same host plants at the same time. That the factors are hereditary 

 would seem in accord Avith all known facts but would require experi- 

 mental proof before it can be established. 



In spite of the fact that the longitudinal veins are not always 

 constant either within the genus or species they are constant enough 

 to furnish good characters. On the basis of wing venation the Ful- 

 gorida' of Eastern North America fall into eight groups. Group one 

 includes the subfamily Fnlgorina' and is distinguished by the follow- 

 ing points : subcosta and radius are not united save for a short dis- 

 tance at the base, radius and medius are united for a considerable dis- 

 tance, cubitus is provided with several accessorj^ veins, the second and 

 third anals are united into a common stem, the surface of the fore 

 wing is reticulated by many cross veins and the hind wing has 

 the anal area reticulate. Group two includes the subfamily Flaiinoe, 

 it may be distinguished as follows: costa is distant from the margin 

 of the wing and united with it by a series of transverse veinlets ; the 

 other veins are distinct and have many accessory veins, second and 

 third anal distinct. The third group includes the subfamily Acana- 

 lonince. This group has the costal vein distinct from the margin but 

 not connected by transverse veinlets, the other veins are distinct and 

 connected by reticulating veinlets, cubitus is unbranched. Group 

 four includes the subfamilies Achilince, DerhincB and Cixiince. The 

 principal character in this group is that subcosta and radius are united 

 for a considerable distance from the base. Group five includes the 

 subfamily DictyopharincB. The members of this subfamily in our 

 fauna have subcosta and radius completely united and with medius 

 and cubitus distinctly two branched before the apical reticulate area. 

 Group six includes the subfamily Delphacince and is perhaps simply 

 an evolution of group four. Subcosta and radius are united as in that 

 group but the single stem of radius after its separation from subcosta 

 is bent anally and merges for a short distance with medius one plus 

 two only to separate again and appear as a distinct vein like a branch 

 of medius. Group seven includes the Issince whose wings are generally 

 so reduced either brachypterous or koelopterous that little can be said 

 about their real character. For the most part the veins are straight 

 and extend from the base to the apex without branching but are con- 



