288 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxii. 



;i Prosternum armed with a pair of spines 4 



Prosternum unarmed 12 



4. Lateral carina' of pronotuni jiresc nt, sharp and distinct 5 



Lateral carina' of pronotum not indicated or very blunt and obscure 7 



5. Posterior tibia' armed 1 )elo\v with two apical spines; ovipositor curved upward . . 6 

 Posterior tibiic armed below with four apical spines; ovipositor straight, except 



rarely in A . pachymerus Atlanticus, p. 320 



6. Lateral carinje of the pronotum behind the ])oint of convergence nearly straight 



or but little bowed outward, causing the disk of the metazone to be trapezi- 



form, the widest part far behind the middle Neduba, p. 295 



Lateral carinse of the pronotum behind the point of convergence strongly bowed 

 outward, causing the disk of the metazona to be of a more or less elongate 

 oval form, the widest part not so far behind the middle Aglaothorax, p. 290 



7. Posterior femora long, much more than twice as long as the j^ronotum, extend- 



ing nmch beyond the tip of the abdomen; pronotum without indications of 



lateral carinte; ovipositor of female, where known, curved upward 8 



Posterior femora short, no more than twice as long as the pronotum, not or 

 scarcely extending beyond the tip of the abdomen; pronotum with obscure, 

 blunt lateral carinte on the posterior third; ovipositor curved downward. 



Apote, p. 327 



8. Pronotum posteriorly more or less elevated, saddle shaped; elytra of the male 



longer than the pronotum ^ 9 



Pronotum straight above, not saddle shaped; elytra of the male less than one- 

 half the length of the pronotum 11 



9. Posterior tibifie armed below with two apical spines; elytra of the male much 



swollen, apically broadly rounded Neoharrettia, p. 302 



Posterior tibiae armed below with four apical sjiines; elytra of the male but little 

 swollen, apically narrowly rounded 10 



10. Elytra of the male with the tympanum occupying moi'e than one-half the length 



of the elytra beyond the pronotum; lateral lobes of the pronotum about as long 



as high; vertex greatly compressed Rhenin, p. 305 



Elytra of the male with the tympanum oecujjying less than one-half the length 

 of the elytra beyond the pronotum; lateral lobes of the pronotum about twice 

 as long as high ; vertex but little compressed Zacyrloptera, p. 308 



11. Prosternal spines distinct; pronotum, except in S. stcrensoni, ateloploides, and 



hruneri, more than 8 mm. in length Siipator, p. 339 



Prosternal spines indistinct or wholly obsolete, rarely sharply triangular; pronotum 

 8J mm. or less in length Ereruopedes, p. 330 



12. Pronotum without indications of lateral carina' on the anterior half or indicated 



only by color 13 



Pronotum with persistent lateral cariufe except sometimes on the anterior 

 fourth^ 18 



13. Posterior femora, except of young specimens, less than twice as long as the 



pronotum 14 



Posterior femora more, usually much more, than twice as long as the 

 ' pronotum 15 



14. Pronotal disk smooth; anterior tibiae armed above on both margins; cerci of the 



male apically furcate, the lower branch long and sharp, fig. 47. .Annhnis, p. 351 



Pronotal disk rough, scabrous; anterior tibi.e armed above on the outer margin 



only; cerci of the male apically expanded but not furcate, the inner corner 



short, tig. 51 1'eranabrus, p. 362 



«The Mexican Idiontatus subcarinatus has the lateral carinse dull but distinct. 



