Buprcstis, Trachys, and Elateh 2&1 



Length two-fifths of an inch. 



Differs from lacunosus, Fab. in magnitude and colour* ia$ 

 well as in the disposition of the thoracic indentations* whicli 

 in that species are placed 2. 1. 2., whereas in the present 

 species they are 2. 3. I obtained it near the Rocky Moun- 

 tains, whilst exploring that country with Major Long's party. 



1 1 E. viridanus. Dull reddish brown j thorax with twd 

 indentations. 



Elater viridanus, Melsh. Catal. 



Description. Head with an obsolete indentation On the 

 vertex : antenna serrate, second joint thicker but shorter 

 than the third : thorax longer than broad, slightly and 

 gradually narrowed before ; two very distinct deeply in- 

 dented punctures before the middle each side ; a lorigi- 

 tudinal slightly indented line extends from the base to the 

 middle ; posterior angles prominent, acute , scutel oval ; 

 elytra with punctured, impressed striae : beneath palar 

 rufous. 



Length seven-twentieths of an inch. 



The anterior indentations of the thorax are situated mucii 

 farther forward than those of the erosus, nob, 



12. E. rotundicollis. Thorax rufous, sub-quadrate, rounded. 



Elater rvficollis, Melsh. Catak 



Description. Head blackish piceons, irregularly punctured,, 

 transverse frontal line obtuse : thorax rufous, conveXj, 

 quadrate ; anterior and posterior diameters equal, and 

 equal to- the longitudinal diameter ; anterior angles Ob- 

 tusely rounded, much wider than the head ; edge a little 

 contracted before the posterior angles, which are a little 



