322 AMERICAN PACHYBRACHYS (cOLEOPTERa) 



clieyisis the elytra are mostly black, and to lessen the chances of 

 error these have been tabulated also in Group E. 



1. Punctuation of elytra in great part confused 2 



Punctuation of elytra arranged in tolerably regular series (less conspicu- 

 ously so in piduratus) 4 



2. Terminal spur of front tibia wanting or very rudimentary; last joint of 



maxillary palpi scarcely differing in the sexes; punctuation coarser and 



denser 145. viduatus 



Terminal spur of front tibia normally developed; last joint of maxillary 

 palpi more widely truncate in the cf ; punctuation finer and less dense. . . .3 



3. Eyes in cf separated by a distance evidently less than twice the length of 



the basal antennal joint; elytra bivittate, the outer stripe rarely if ever 

 continuous, and usually interrupted to form three sjjots, one or more of 



which may be lacking 128. bivittatus 



Eyes in cf separated by at least twice the length of the basal antennal joint. 

 Elj^ra occasionally with a single narrow vitta, with or without faint 

 traces of lateral spots, but usually entirely destitute of markings; sub- 

 marginal stria much confused; eyes in cf separated by twice the length 



of the basal antennal joint, or a little more 129. sublimatus* 



Elytra each with a single broad discal vitta; eyes separated by from 2 J 

 to 3 times the length of the basal antennal joint. 



Eyes in 9 less widely separated than their own vertical length ; the 



submarginal stria nearly regular 130. circumcinctus 



Eyes in 9 more widely separated than their own vertical length; 

 submarginal stria more confused 131. consimilis 



4. Prothorax densely strigate punctate, a smooth median yellow line which 



does not reach the base 139. othonus 



Prothorax less densely, usually rather sparsely punctate, not strigose (rarely 

 somewhat so towards the sides in some examples oijanus) 5 



5. Elytra yellow, with suture or sutural bead and two discal vittae on each 



black or brownish. 



Front claws of cf distinctly enlarged; lustre dull, outer eK-lral vitta con- 

 fined to the 7th and 8th interspaces 135. pawnee 



Front claws of cf not enlarged. 



Head and prothorax with more or less evident alutaceous sculi)ture 

 (very fine and visible only on the head and toward the sides of the 

 prothorax in some examples of aulolycus). 



Prothorax strongly trans-^verse, more closely punctate. (Plains 

 west of Mississippi River to the Rocky Mts.) . . 141. autolycus 

 Prothorax moderately transverse, more sparsely pimctate, and 

 always distinctly alutaceous. (Atlantic Coast.).. 132. litigiosus 

 Integuments pohshed, alutaceous sculpture not present except occa- 

 sionally very faintly on the head. 



Outer elytral vitta confined to the 7th and 8th interspaces; me- 

 dian pronotal stripe conspicuous^ V-shaped. 

 Vittae black 136. vau 



