312 AMERICAN PACHYBRACHYS (cOLEOPTERa) 



Eyes of 9 separated by the length of the basal antennal joint or scarcely 

 more; front with feeble ocular lines 42. longus 



13. Front claws of cf not appreciably larger than those of the middle and hind 



feet 14 



Front claws of cf evidently larger than the others 20 



14. Front without ocular lines 15 



Front with more or less distinct ocular lines 18 



15. Integuments poUshed; front as a rule more sparsely punctate 16 



Integuments finely alutaceous, scarcely shining; front more closely 



punctate 17 



16. Labrum rather deeply emarginate; form more robust; elytra more con- 



spicuously wider at base than the prothorax; color deeper yellow, size 



larger 17. xantholucens 



Labrum broadly feebly sinuato-truncate; form less robust, humeri less 

 broadly exposed, size smaller. 

 Eyes in cf separated by fully twice the length of the basal antennal joint ; 

 antennae (cT) not quite so long, the 10th joint scarcely 3 times as long 



as wide; elytral striae more regular 29. mercurialis 



Eyes in (f separated by about If times the length of the basal an- 

 tennal joint; antennae (d^) nearly as long as the entire body, the 10th 



joint 4 times as long as wide 124. nubilus* 



Eyes in <^ separated by about If times the length of the basal an- 

 tennal joint; antennae as in nubilus; elytral striae more broken and 

 confused 125. conspirator* 



17. Prothoracic M diffuse but nearly complete, punctuation of elytra coarser 



and less confused, size smaller 31. mitis 



Prothoracic M represented by three small basal spots, of which the lateral 

 ones are often faint; punctures of elytra finer, more numerous and more 

 confused 30. parvinotatus 



18. Eyes separated by fully 3 times the length of the basal antennal joint in 



the cf; front polished, ocular lines fine; color pale whitish yellow. 



32. coloradensis 

 Eyes separated by from 2 to 2f times the length of the basal antennal 

 joint in the cf ; ocular lines very distinct. 

 Prothorax with a usually nearly parallel and entire rufo-testaceous stripe 



occupying the middle third 28. livens 



Prothorax without median darker stripe 33. minor 



Eyes separated by about If times the length of the basal antennal joint 

 in the cT 19 



19. Elytral striae nearly regular throughout, confused only in a small scutellar 



area; prothorax small, sides nearly straight 34. nero 



Elytral striae badly broken or contorted at the middle of the disk. 



Prothorax a little shorter and more transverse, median spot narrowly 

 divided apically; striae finer, elytra with seemingly no tendency to lat- 

 eral maculation but with the suture often darker 35. petronius 



Prothorax slightly less transverse, sides a trifle more rounded, median 

 spot less narrowly divid(Hl; lateral spots of elytra sometimes imlicated; 

 striae less fine, more imjiressed 36. tacitus 



