H. C. FALL. 97 



B. versicolor; B. timidum; B. pictum. 



I cannot at all agree with Hayward in his interpretation of 

 the above named forms, and am convinced after a study of 

 the types that the Henshaw List is correct in giving pictum 

 specific standing, and that timidum is really a synonym of 

 versicolor as was previously supposed. 



Hayward separates versicolor and timidum primarily on the 

 completeness of the lateral striae of the elytra, these being 

 abbreviated behind in the former, and entire in the latter. 

 To this is added — head usually more evidently alutaceous in 

 timidum and the prothorax more strongly rounded in front 

 and more sinuate behind in versicolor. My own study leads 

 me to believe that it is impossible to base a distinction on 

 the lateral striae, as every degree between the extremes may 

 be found in a large series of specimens, which are so com- 

 pletely in accord in other respects that their identity can not 

 be doubted. If, however, we take the secondary character 

 above mentioned, separation of the two species is not difficult. 

 The type of versicolor is from Lake Superior; it has the head 

 distinctly alutaceous, the sides of the prothorax nearly as 

 much so, the surface becoming smoother at the middle, sides 

 of thorax moderately rounded and sinuate. This species is 

 an abundant one in the northern half of the United States 

 and Canada, extending from the Atlantic to the Pacific. The 

 western specimens are more likely to have the lateral striae 

 of the elytra entire, and one of these from the Rocky 

 Mountains served as the type of timidum. Fiction was also 

 described from the Rocky Mountains. It is almost invari- 

 ably smaller than versicolor, the head not alutaceous except 

 very finely so posteriorly, the front between the eyes always 

 polished, the prothorax polished throughout and more deeply 

 sinuate behind. The lateral striae vary in their development 

 in the same way as in versicolor, and as a result specimens 

 are indiscriminately mixed with versicolor and timidum as 

 separated by Hayward. 



I do not know how far versicolor extends its range in the 

 east, nor how for east and north pictum occurs, but versicolor 

 is essentially a northern and pictum a southern species. On 



TRANS. AM. ENT. SOC, XXXVI. (13) MAY, 1910. 



