COLEOPTEUA. 21 



Punctures joined or eoalescent ; sometimes rarely, in twos or threes, in other 

 cases in longer channels, in others still in very long channels, with 

 scarcely a trace of individual punctures upon any portion of the surface. 

 The channels when they exist may be extremely tortuous, but unless 

 they exhibit a completed spiral vortex or whirl at one point at least, 

 they will belong to this subdivision. The channels or punctures may 

 be comparatively distant or very closely compacted, and the interspaces 

 correspondingly wide or acute, convex or flat, highly polished or minutely 

 granulose and feebly shining. 



Prothorax canaliculated 8. 



Prothorax not canaliculated y. 



Punctures all isolated and distinct J. 



Subdivision «. 



The species under this title attain the highest form of development 

 to be observed in the genus, and are generally large and robust, active 

 and comparatively powerful. 



The forms apparently demanding specific recognition may be 

 classified as follows : — 



Transverse carinae of abdomen tricuspid. 

 Legs black beneath. 



Pronotum having, in addition to the canaliculation, a punctifonn im- 

 pression near each anterior and posterior angle. 



Prothorax widest slightly behind the middle S. sculpt i lis. 



Prothorax widest far in advance of the middle 9. laccopllilus. 



Prothorax devoid of the punciiform impressions. 

 Elytral suture much longer than the pronotum. 



Interocular surface rather deeply excavated ; longitudinal elevation 

 distinct ; canaliculation of pronotum distinct. 



Head as wide as the elytra at base 10. jlliio. 



Head much narrower than the elytra 11. verticosus. 



Interocular surface feebly excavated : longitudinal elevation very 

 feeble; canaliculation of the pronotum reduced to a very slight 



erosion 12. tristis. 



Elytral suture rather shorter than the pronotum ; body depressed : 



prothorax very robust 13. A list in i. 



Legs not black beneath. 



Form very slender ; sculpture extremely coarse ; interocular surface very 

 narrow, much less than twice as wide as the eye ; length 4.4 mm. 



14. ranops. 

 Form more robust ; interocular surface at least twice as wide as the eye : 

 length generally much less than 4 mm. 

 Elytral suture about as long as the pronotum. 



Sides of prothorax scarcely sinuate behind ; surface of pronotum 

 very distantly and finely punctate, vei-y highly polished. Middle 

 States 15. delawarensis. 



