AMERICAN COLEOPTERA. 141 



Sides of prothorax arcuate, not distinctly convergent anteriorly; front an- 

 gles well defined. 

 Blackish, prothorax paler and evidently granulate; ninth joint of antenna 1 



equal to the three preceding. . . ■ ■■ 5. collaris. 



Fuscotestaceous, prothorax not granulate, ninth joint of antennas ( %, ?) 



equal to the three preceding; tarsi rather stout 6. aliitaceiis. 



Fusco- or rufotestaceous. prothorax granulate, ninth joint of antennae fully 

 equal to the four preceding, tarsi slender. 

 Front ( % ) a little less than twice as wide as the longest diameter of the 

 eye and scarcely two and one-half times its width ; sixth ventral 



deeply cleft 7. crotchii. 



Front ( %1) fully twice as wide as the longest diameter of the eye and 

 about three times the width of the latter; sixth ventral broadly emar- 



ginate 8. gracilis. 



Ninth joint of antenna; as long as the five or six preceding united in the male 

 (Rocky Mt. and Pacific Coast species, except lacustris). 

 Pronotum granulate-punctate. 



Piceons brown, size larger (4.8-5.5 mm.), Michigan 9. lacustris. 



Brown, size larger (5.1-5.2 mm.), Arizona 10. fissuralus. 



Black, size smaller (2.4-3.6 mm.), California, Arizona 11. nigra lis. 



Pronotum simply punctate, at least broadly so at middle. 

 Black ( % ), brown ( £> ) ; prothorax transversely impressed. 



12. pallitarsis. 

 Black ( 9 not known) ; prothorax not at all impressed transversely. 



13. tristis. 



Rufotestaceous or brown in both sexes 14. montaiius. 



Ninth joint of antenna? fully equal to the six preceding in the male (Atlantic 

 States species). 

 Fifth joint of antenna; subequal to the fourth and much shorter than the 

 third ; elytra more shining than the. head and pronotum. 

 Head and pronotum opaque, scabrous punctate or feebly granulate, elytra 



shining; color piceous 15. filicornis. 



Head and pronotum granulate and opaque, elytra variable but usually sub- 

 granulate or feebly scabrous toward the base, more shining toward 



the apex ; color rufotestaceous 16. granulalus. 



Fifth joint of antennae much longer than the fourth and subequal to the 

 third; elytra less shining than the head and pronotum. .17. opicus. 

 Ninth joint of antennas nearly equal to all the preceding in the male; joints 

 6-8 quite strongly transverse, the eighth sublenticular in the male 

 (Atlantic States). 

 Head and prothorax black or piceous, the elytra testaceous in the male; 

 head and prothorax usually a little darker than but sometimes con- 



colorous with the elytra in the female 18. luteipemiis. 



Entirely rufotestaceous 19. tenuicoriiis. 



Dark brown, ninth joint of antennas equal to the five preceding in the male, a 

 little longer than the three preceding in the female; last ventral seg- 

 ment more or less evidently bituberculate in the female. 



20. marginicollis. 



TRANS. AM. ENT. SOC. XXXI. APRIL, 1905. 



