320 AMERICAN PACHYBRACHYS (cOLEOPTERa) 



Standard elj^tral spots wanting except the basal and apical ones of the outer 

 series. (Georgia.) 109. quadri-oculatus 



Standard elytral spots — except the one on the humeral umbo — wanting or 

 but faintly indicated. (Texas.) 110. fractus 



44. Front claws of cf more perceptibly enlarged; eyes in cf separated b>- about 



If times the length of the basal antennal joint; 10th joint of antennae less 

 than three times as long as wide; legs almost entirely j-ellow. (Arizona.) 



111. truncatus 

 Front claws of c^ scarcely perceptibly enlarged 45 



45. Elytral punctuation confused in baso-sutural region, elsewhere more or 



less distinctly striate. 



Baso-sutural region of confused punctuation rather small, pygidial yel- 

 low spots moderate to large. 



Eyes of d^ separated by about 1| times the length of the basal an- 

 tennal joint or slightly more, or by a distance scarcely or barely as 

 great as the vertical width of their upper lobes; antennae more 

 slender, the 10th joint more than three times as long as wide. 



(Arizona to Texas.) 112. precarius 



Eyes of c? separated by twice the length of the basal antennal joint, 

 a distance distinctly greater than the width of their upper lobes; 

 antennae a Httle less slender, the 10th joint (cf) not more than 



three times as long as wide. (Arizona.) 113. nogalicus 



Baso-sutural region of confused punctuation much more extended, the 

 punctures more densely placed; prothorax and pygidium predomi- 

 nantly black, apical spots of the latter small or wanting. (New 



Mexico to Arizona.) 114. croftus 



Elytral punctuation confused as far as the submarginal stria, no well de- 

 fined striae postero-laterally; size larger. (Arizona to Texas.) 



115. sonorensis 



46. Elytra without impressed striae, the punctures confusedly dispersed 



almost throughout. (Arizona.) 21. insidiosus 



Elytra with distinct striae at rear and sides; punctures confused in baso- 

 sutural region. 



More robust, prothorax widest at basal ^ or |, sides strongly rounded. 



(Texas.) 6.3. brevicornis 



Less robust, prothorax widest very near the base, sides slight h- to mod- 

 erately rounded. 



Lateral thoracic spot quadrate, solid or entire, not connected with 

 the median stripe (rarely slightly so) ; elytral spots usually fused 

 into two sharply outlined transverse fasciae connected along the 

 suture, the humeral spots, however, often isolated. (Eastern 



United States.) 120. tridens 



Lateral thoracic spot more or less irregular or disintegrated exteri- 

 orly, often connected with the median stripe; elytral maculation 

 more irregular, the standard sjjots all more or less distinct, though 

 frecjuently confluent in part. (Eastern United States.) 



121. obsoletus 



