149 



"Delphax" 



Keiisia Fieber, 1. c. type gnttula (Germ.) 



Chloriona, Fieber, 1. c. type iinicolor (H.-S.) 



Delphax Fieber, op. c, 520, (nee Fabr. ) 



Dclphaciiiiis Fieber, 1. c. type uicsomelas (Boh.) 



Delphacodcs Fieber, op. c. 524 type niiilsaiifi Fieb. 



Liburnia auctt. nee Stal. 



Chlorionidea Loew 1885 \'erh. Zool. bot. Ges. W'ien XXX V 

 356 type flava Loew. 



Delphax Fieber, op. c, 520 (nee Fabr.) 



Delphacissa Kirkakly 1906 Entoni, type nncinata. 



Sogata Distant 1906 Faun. Ind. Rlivnch. Ill, 465, type dohcrtyi 

 Dist. 



Nilapavvata Distant 1. c. type greeiii Dist. 



The above citation does not mean that I consider all these 

 groups to form one genus- but simply that I cannot yet arrange 

 the Australian and Fijian species under them, on the char- 

 acters proposed for them. One difficulty lies in the large propor- 

 tion of forms known only in a brachypterous state. Then again 

 I place little reliance on many trusted characters. 



Distant has used the length of the head, both dorsally and 

 ventrally, as a principal character; this I cannot admit. The 

 fact that the head is longer than wide dorsally as opposed to 

 not longer than wide, if unaccompanied by other strong char- 

 acters, is to me of no generic value. The same, in perhaps a 

 rather less degree, with the frons' and also in this case as 

 regards the contour. The comparative length of the cylindric 

 antennae is also, within certain limits, not I think, of generic 

 value. 



Great stress is laid on the lateral keels of the pronotum, ex- 

 cept by Distant, who disregards them. This seems to me a 

 somewhat variable character and in any case a very difficult 

 one to appreciate. In a few forms these keels are no doubt 

 sharply separable into two categories, viz: (i) those which are 

 straig'ht' scarcely divergent posteriorlv and reach the posterior 

 margin of the pronotum, and (2) those which curve under the 

 eyes and never reach the posterior margin. There are a large 

 number of forms however which are intermediate, which pro- 

 ceed straightly in fact but fork not far from the posterior mar- 

 gin and proceed obscurely in two directions, under the eves and 

 obscurely to the posterior margin. There are also intermediate 



