20 COLEOPTERA OF NORTH AMERICA. 



Those with the two supra-orbital setaj will be considered first, 

 and for convenience of reference will be called by the following 

 name. 



Harpalin^ bisetos^. 



This section contains by far the larger number of tribes and 

 genera and presents many difficulties in its study. Many of the 

 characters used in the table are the common property of science, 

 oMiers are new or are now brought into greater })rominence. 



As in the Carabine, it appears to have escaped notice that a 

 juiniber of genera have the posterior co.xa^ separated so that the 

 nietasternuni and abdomen meet. This is an important character 

 and its use is attended with good results. 



The internal elytra! plica by its presence serves to separate a 

 number of trii)es. The ol)ject of this structure is to afford a 

 ]neans of supi)ort to the edge of the abdomen, and at the origin 

 of the plica posteriorly the last ventral segment is firmly held 

 when in repose. It will be observed that in those genera with a 

 plica the upper edges of the venti-al segments arc vertical, those 

 without the plica have the edge infle.xcd. As a rule the plicifer- 

 ous genera are terrestrial and are at l)est feeble fiyei«, the majority 

 of the others are easy flyers and le.'^s terrestrial in their habits. 

 This however is merely a general statement with many exceptions 

 on both sides. 



The tribe Panaggeini is placed qt the head in the belief that 

 some of its members will show a closer relationship with the 

 Clivivce. than has yet been indicated. 



The tribes in our fauna may be distinguished as follows: — 



Mandibles with a Hetifrorous inuicture in the groove (scrobe) on the outer 

 side. 

 Anteniic-e slender with at most two basal joints glabrous. The abdoniinal 

 segments entirely corneous. 

 Last joint of palpi subulate. Mesosternal ei)imi"ra wide. 



XVI. Bembidhni. 



Last joint of palpi slender — elongate or snlicylindrical. Mesosternal 



epimera narrow. XVIT. Pogonini. 



Antenna^ moniliform or slightly compressed externally, four basal joints 



glabrous. (The abdominal segments 3— 4-.5 narrowly coriaceou.s on 



their posterior margins in Nomius.) XIIL NoMimr. 



