﻿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 mesonotmn 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 variable, especially in the apical cells. The brachial 

 and radial are nearly always forked near the subapicnl line. 

 The median vein continues direct to the apical margin of the 

 tegmen in Asiraca, Conomcliis, Crioinorphiis, Tropidoccfliala and 

 Mctropis, but ends at the subapical line in Jassidaeits, Dclphacodcs 

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

 forms at least) a small stridnlatory area. (See 'Tntroduction.") 



Legs. 



The legs afTord good characters. 



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

 genera, however, thev are cylindric. 



A good character is afforded bv the mobile spur of the hind 

 tibiae, which has not up to the present ])een fullv utilized. There 

 are three principal forms: 



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

 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 Protcrosydne, 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. 



