124 



1. Lateral keels straight, meeting the hind margin, 



2. Lateral keels curved, not meeting the hind margin. 

 Very often however the keels fork near the hind margin, one 



fork reaching the hind margin while the other curves outwards. 

 The scutellum of the mesonotum may be i, 3, 4 or 5 keeled; 

 this is useful for generic separation. 



Venation. 



The venation is of comparatively little importance, as it is 

 often very varialde, especially in the apical cells. The brachial 

 and radial are nearly always forked near the subapical line. 

 The median vein continues direct to the apical margin of the 

 tegmen in Asiraca, Cononichis, Crioniorf-lnis, Tropidoccphala and 

 Metro pis, but ends at the subapical line in Jassidaciis, DclpJiacodc^ 

 and its allies. The wings have (generallv in the long-winged 

 forms at least) a small stridnlatory area. (vSee "Introduction.") 



Legs. 



The legs afTord good characters. 



In Asiraca, and PJiyllodiiiiis, the fore pair are dilated, in other 

 genera, however, they are cylindric. 



A good character is afTorded bv the mobile spur of tlie hind 

 tibiae, which has not up to the present been fidlv utilizefl. There 

 are three principal forms: 



(i) probably the original, in which it is simple, awl-sliaped. 

 not provided with a fringe of teeth, but only one apical tooth. 

 This occurs in Asiraca, Melanesia and Ugyops. 



(2) the. usual form; large, bilaminate, with a row of many, 

 very feeble, minute teeth : the species are probable grass-feeders. 



(3) solid, subcultrate. elongate, narrow and strongly com- 

 pressed, with a row of a few. large, strong teeth. This form is 

 that of all the endemic Hawaiian species, but otherwise only 

 known to me in Proterosydnc, an Australian genus. 



As the Hawaiian forms are all arboreal, this may be the char- 

 acteristic spur of arboreal species. 



Genitalia. 



The genitalia in the male are the final test of a species and 

 even afford generic criteria. 



