KEY TO THE TRIBES 33 



Antennae with their articulations contiguous to subcontiguous; in- 

 serted on a median, swollen, antennal tubercle; antennae with a 

 conspicuously elongated first segment, and strongly geniculated 



(PI. XVIII, 4) METOPIINI 



(p. 204) 



12. Antennae straight, not geniculate TYCHINI 



(p. 260) 



Antennae strongly geniculate GONIACERINI 



(p. 283) 



13. Tarsi with a single claw PSELAPHINI 



(p. 286) 

 Tarsi with two equal or unequal claws 14 



14. Body pubescence in the form of scales (PI. IV, 6-8) . . CTENISTINI ^ 



(p. 291) 

 Body pubescence diverse but never in the form of scales 15 



15. Pronotum always with one, two, or three basal foveae which may 



be free or connected by a transverse, arcuate basal sulcus; elytra 

 usually with basal foveae; maxillary palpi usually large and very 

 conspicuous TYRINI ^ 



(p. 295) 

 Pronotum and elytra lacking foveae and sulci; the maxillary 

 palpi very minute; known only from the nests of leaf-cutting 

 ants ATTAPSENINI 



(p. 348) 



^ In the Western Hemisphere the Hybocephalini (p. 289) are limited to a single genus 

 {Ephimia). This rare genus is atypical of its tribe, and may belong in the Tyrini. Since 

 Ephimia may not be easily separated from Tyrini and Ctenistini, it is taken care of in 

 both of these tribes. 



