North American Species of Trocjoyldceus. 349 



Antennas short, not longer than the head and prothorax; 

 size small; head almost as wide as the prothorax. 



32 agonus 

 Pronotal impressions feeble and not at all conspicuous. 

 Elytra short, much wider than long. 

 Antennae short, about as long as the head and prothorax. 



33 temporalis 

 Antennae long, fully attaining the middle of the elytra. 



34 probu» 

 Elytra quadrate or very slightly shorter than wide. 

 Form slender; legs piceous; antennae fuscous, 35 nanulus 

 Form more robust; legs and antennae pale flavate. 



36 modestus 



Elytra very short, subequal in length to the prothorax; integu- 

 ments very finely, strongly granulose and completely dull. 



37 bracliypterus 

 Prothorax very slightly wider than long, very feebly or not at all 

 impressed. 

 Sides of prothorax very broadly and almost evenly arcuate, being 

 feebly convergent from apex to base; small, extremely 

 slender species. 

 Antennae short, not longer than the head and prothorax. 



Piceous; elytra paler, rufescent 38 pertenui» 



Piceous-black throughout 39 detractus 



Antennae more slender, distinctly longer than the head and 



prothorax 40 indigent 



Sides of prothorax strongly rounded anteriorly, convergent and 

 nearly straight toward base; size very large. 

 Very slender, linear; pronotuni granulose, densely and rather 

 indistinctly punctate; elytra rather finely and much more 



sparsely punctate 41 grapliiciii^ 



More robust, linear; pronotum and elytra coarsely, deeply, and 



subconfluently punctate 42 iiigen» 



Eyes larger; the tempora not more than one-half as long. 



Tempora not less prominent than the eye o 43 incertus 



Tempora very distinctly less prominent than the eye. . 44 delicatu» 



I'he number of undiscovered forms in this group probably ex- 

 ceeds that of all the others combined; under these circum- 

 stances it is impossible to prevent doubt on the part of one 

 attempting to identify any independent collection by its means 

 alone. Ambiguity may possibly be considerably lessened by 

 making full use of the descriptions which follow, and to which 

 alone the above table is intended to serve as a key. 



