tryxalin^e. 33 



the head variable, but never so smooth as in the 



preceding forms : insects of moderate or small size 



(except Plectrotettix) . 



f. Eyes elongate, nearly twice as long as broad ; frontal 



costa broad, advanced in front of the eyes by more 



than half the shorter diameter of the latter; tegmina 



with definite pantherine pattern . Plectiiotettix, McNeill. 



ff. Eyes suborbicular, much less than half as high again as 

 broad, frontal costa not prominent, advanced in front 

 of the eyes by less than half the shorter diameter of 

 latter ; tegmina irregularly and obscurely flecked. 

 g. Pronotum subtruncate posteriorly, the prozona 

 much longer -than the metazona ; tegmina and 

 wings abbreviate. 

 h. Head unusually large; pronotum much con- 

 stricted in middle, the lateral carinse well 



developed Eupnigodes, McNeill. 



hh. Head not unusually large; the pronotum but 

 little constricted in middle, the lateral carinse 



almost obliterated Zapata, Bruner. 



gg. Pronotum more or less angulate posteriorly, the 

 prozona and metazona equal or subequal ; tegmina 

 and wings fully developed. 

 h. Pronotum constricted in the middle, the prozona 

 slightly the shorter ; lateral carinse percurrent, 

 more or less divergent in front and strongly 

 divergent behind. 

 i. Foveolae of vertex visible from above only on 

 the inner half; lateral carinse of pronotum 

 anteriorly but little or at least not strongly 

 divergent, being gently arcuate on the pro- 

 zona ; lateral lobes of prozona feebly or not 

 marked above the middle with obliquely dis- 

 posed short lunate carinules Psoloessa, Scudder. 



ii. Foveolse of vertex visible from above throughout 

 their length ; lateral carinse of pronotum very 

 strongly divergent in front as well as behind, 

 being, strongly bent-arcuate on the prozona; 

 lateral lobes of prozona more or less con- 

 spicuously rugose-carinate obliquely above 



the middle Stirapleura, Scudder. 



hh. Pronotum not constricted in the middle, the 

 prozona slightly the longer ; lateral carinas 

 obsolete on the prozona, moderately divergent 



behind Ageneotettix, McNeill. 



biol. centk.-amee., Orthopt., Vol. II., January 1904. Ff 



