yo MEMOIRS ON THE COLEOPTERA 



Abdomen densely and suffusedly punctured toward the sides; mentum 

 without vestige of tooth; elytra without dorsal puncture and with 

 very feeble apical sinus; body large in size. . Group I (caliginosus) 



Abdomen not punctured toward the sides; mentum tooth variable.. . .2 



2 Elytra externally dentate at apex, at the anterior limit of the sinus. . 3 



Elytra feebly sinuate externally or truncate at tip, not in the least dentate, 

 the sinus rarely obsolete 4 



3 Elytra and abdomen never punctulate discally and without dorsal 

 setigerous puncture; body unusually elongate. Group II (erraticus) 



Elytra with suffused close-set punctuation laterally and apically and with 

 a dorsal setigerous puncture, which is however inconstant and fre- 

 quently wanting on one or both elytra; abdomen with suffused sparse 

 punctulation which is obsolescent laterally. . Group III (veriditzneus) 



4 Sides of the prothorax parallel or nearly so 5 



Sides of the prothorax converging from about the middle to the base; 

 body rather small in size and smooth 9 



5 Abdomen without accessory setae, that is, setae arising from sparse 

 punctures irregularly disposed and sometimes transversely sublinear 

 in arrangement 6 



Abdomen with accessory setae 8 



6 Abdomen with fine sparse punctulation toward the basal parts of the 

 segments; elytra truncate at tip in the female, slightly oblique in 

 the male Group IV (amputatus) . 



Abdomen without fine punctulation, other than the usual basal punc- 

 tures 7 



7 Pronotum flattened and strongly, densely punctured latero-basally 

 and with large feeble vague foveae; body rather large in size as a 

 rule, the elytra generally without or rarely with a dorsal setigerous 

 puncture and generally with more or less obvious suffused punctu- 

 lation laterally, in the female of several species pervading the entire 

 surface in a conspicuous manner; mentum tooth usually distinct; 

 tarsal joints more or less hairy above Group V (pennsylvanicus) 



Pronotum not distinctly flattened or very conspicuously punctured 

 latero-basally, the foveae generally rather deeply impressed and 

 less vague than in V; body frequently more abbreviated except in 

 the smaller species, the elytra never having suffused punctuation 

 in either sex, though often very opaque in the female; elytra with a 

 single discal setigerous punctuie, very constant and but very rarely 

 wanting; mentum tooth feeble and inconstant, sometimes wholly 

 obsolete; tarsi wholly glabrous above as usual. .Group VI (viduus) 



8 Body in form and facies nearly as in VI, rather diversified in size and 

 outline, the pronotum and elytra similar, the single setigerous elytral 

 puncture very constant as in that group. .. Group VII (jraternus) 



9 Form rather narrow, moderately convex; pronotum feebly modified 

 basally; elytra with a single discal setigerous puncture; abdomen 

 without accessory setae Group VIII (spadiceus) 



These groups are of very unequal extent, the first and third 

 being represented at present by single species and the eighth by 



