THE CANADIAN ENTOMOLOGIST. 209 



The spine-like, subulate spur is the most primitive and 

 some of its possessors show the more generalized form of tegmina. 

 The solid cultrate spur with both surfaces convex (Delphacini, 

 Section A) appears to be the next stage, which is followed by 

 the inner surface becoming concave (Section B) and eventually 

 laminate (Section C). Section A is of interest as, with the ex- 

 ception of Proterosydne^ with one Australian and one American 

 species, all the genera at present known are Hawaiian. With the 

 exception of three species off grasses and sedges which are placed 

 in Kelesia, all the native Hawaiian Delphacidie belong to this 

 section and are not attached to grasses. Swezeyf has shown that 

 Nesodryas freycinetice has but an apical tooth on the spur in first 

 instar, those on the hind edge appearing at later instars. Section 

 B contains six genera; of these, five, of which the habits are 

 known, are attached to grasses. It is highly probable that 

 further study will add several more to this section. 



The antennce. These organs come next to the spur for useful- 

 ness in taxonomic work; there appears to be but little specific 

 variation and an absence of the sexual differences found in some 

 of the other families of Fulgoroidea. The terete form is probably 

 the more primitive, and the short basal joint more primitive than 

 the longer basal joint. 



The wesonotal carince. These are of great utility as they are 

 always mentioned by describers and of their presence or absence 

 there is little dispute. 



The pronotal carince. Among some of the more dif^cult 

 genera of section C of the Delphacini it is necessary not only to 

 recognize the presence of these carina? but also their shape and 

 extension. Unless this is done it will be difftcult to keep apart 

 several genera containing different forms, and it will lead to the 

 formation of one or more unwieldy genera of polymorphic char- 

 acter, whose species it will be more difficult to locate than are the 

 present genera. This has been the case with Crawford's work on 

 the north American forms and it will be still worse if the same 

 methods are applied to the genera of the world. 



It is generally possible to recognize two forms, those divergingly 



*Crawford wrongly states this genus to be Hawaiian. 

 fProc. Haw. Ent. Soc, II., Ki. 



