310 AMERICAN PACHYBRACHYS (cOLEOPTERA) 



basal antennal joint, their distance asunder nearly equalling the verti- 

 cal length of the eye 12. donneri 



Color similar to donneri, except that the discal pale markings are more 

 conspicuous; eyes in the cf separated by twice the length of the basal 

 antennal joint, the distance obviously less than the vertical length of the 

 eye; prothoracic punctuation finer 13. uteanus 



Group B 

 (Starred species (*) are tabulated in more than one group.) 

 This group includes those species which are — so far as our 

 experience goes — normally almost entirely yellow or testaceous, 

 at least so far as the elytra are concerned. In diversus and 

 petronius the elytra are sometimes more or less suffused with 

 brown along the suture, but seemingly always without lateral 

 spots. In tacitus the brown color of the punctures may also 

 become suffused along the striae posteriorly, forming incipient 

 markings, while in pundatus * (especially in the female), con- 

 victus* suhlimatus* nuhilus* conspirator* caelatus * and tnitis, 

 specimens have been seen with some of the elytral markings 

 more or less developed, though these are usually quite small and 

 inconspicuous. 



1. Prothorax with broad heavily marked black M; size rather large (3.5 to 4..5 



mm.); elytral striae all regular and entire 138. pallidipennis 



Prothoracic M never black and sharply defined; elytral striation les.s perfect, 

 often very imperfect or wanting 2 



2. Prothorax as wide at base as the base of the elytra (at least in the 9), 



strongly narrowed in front; punctuation very much finer than that of the 



elytra 15. purus 



Prothorax often very nearly but never with the basal width absolutely equal 

 to that of the elytra 3 



3. Prothorax and elytra with a more or less evident secondary system of fine 



rather sparse interstitial punctures 16. mellitus 



Prothorax and elytra without obvious interstitial punctuation (a few very 

 minute punctures are detectable — especially on the prothorax — of certain 

 species) 4 



4. Marginal interspace of the elytra more or less conspicuously punctate, the 



submarginal (8th) stria often ill defined or even completely confused with 



the punctures of the interspace 5 



Marginal interspace of elytra either impunctatc or at most with a few punc- 

 tures at or near the post-humeral interruption of the 8th stria 11 



5. Front with ocular lines 6 



Front without ocular lines 9 



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



feet " 



Front claws of tf obviously enlarged 8 



