196 AMERICAN COLEOPTERA. 



panies this paper. The figures are in the main diagramatic, the 

 minor details being omitted lest they might mislead the student. 

 All have been drawn under high power, so that in those represent- 

 ing the elytra, which have all been drawn on the same scale, more 

 stria' are shown in several cases, than appear when the specimen is 

 magnified to a less degree. 



In conclusion, I would ask a little indulgence of those who use 

 this paper. No one can realize its shortcomings more fully than 1, 

 but if its publication shall lead to a better understanding of our 

 species, my object will have been accomplished. 



Forty-five species are recognized in the following pages. These 

 are divided into nine groups, which may thus be separated : 



Elytra rounded at tip ; head not inserted in the thorax to the eyes 2. 



Elytra sub truncate at tip, the third stria with one very small dorsal puncture 

 near the apex ; head inserted in the thorax to the eyes; men turn with- 

 out forameniform punctures Group i. senescens. 



2. Mentum without forameniform punctures; marginal stria of elytra interrupted 



or less deep at middle 3. 



Mentum with two large, forameniform punctures behind the tooth 5. 



3. Thorax narrowly margined, the margin not translucent 4. 



Thorax broadly margined, the margin translucent; elytra with the recurved 



portiou of the sutural stria parallel to the margin, third interval with 

 two small dorsal puuctures very near the third stria. 



Group iii. flavicauda. 



4. Elytra with the recurved portion of the sutural stria parallel to the margin ; 



dorsal punctures two, the first on the fourth stria near the base, the 



second on the third stria near the apex Group ii. nanus. 



Elytra with the recurved portion of the sutural stria short, nearly parallel to 

 the suture; dorsal puuctures two, these placed on the third stria when 

 the latter is present, the second at most but slightly behind the mid- 

 dle Group iv. incurvus. 



5. Elytra with the marginal stria broadly interrupted at middle (obsolete in 



Itevus) 6. 



Elytra with the marginal stria deep, entire; two small dorsal punctures on the 

 third interval Group vi. ephippiatus. 



6. Recurved portion of the sutural stria long, nearly parallel to the suture, dis- 



tinctly hooked at tip. ... 7. 



Recurved portion of the sutural stria moderately long, not hooked at tip; two 

 dorsal punctures on the third stria, the second but slightly behind the 

 middle ; form convex Group v. frontalis. 



Recurved portion of the sutural stria very short, parallel with the suture, not 

 hooked at tip; two dorsal punctures on the third interval near the 

 third stria, the secoud very distinctly behind the middle; form de- 

 pressed Group vii. lsevus. 



7. Elytra with the first dorsal puncture on the third stria, the second at or behind 



the tip of the recurved portion of the sutural stria, but not enclosed 

 within it Group viii. vittiger. 



