COLEOPTERA. 95 



The following table exhibits the arrangement adopted for the 

 species under examination, but which before many years will repre- 

 sent, without doubt, scarcely more than two-thirds of the forms which 

 will then be known, and it is even incomplete at the present day, as 

 I have seen at least one undescribed species not here represented. 



In cavicollis there is a very feeble broadly impressed area in the 

 middle of the pronotal disk, which appears to be a rudimentary canali- 

 culation ; it is, however, so feeble that I have placed the species in 

 the second group; its very distinct form of protliorax will distinguish 

 it without trouble. 



Pronotum having a distinct medial longitudinal canaliculation or elongated 

 canaliculate puncture. 

 Under surface of head having a large pad of erect sensitive setae ; canali- 

 culation of pronotum very narrow, extending with equal width from the 



base to the apex 1. caiialicillatlis. 



Under surface of the head without the large area of sensitive setae ; canali- 

 culation short. 

 Form generally somewhat robust ; head strongly convex and deeply im- 

 pressed hehind the frontal ridge ; interocular surface not distinctly 

 punctate. 

 Minute species, not exceeding 0.8 mm. in length. 



Forna robust ; color reddish-testaceous..... 2. piiniillis. 



Form moi-e slender; color dark blackish-castaneous ....3. debilis. 

 Larger species, not less than 1.3 mm. in length. 



Prothorax longer than wide ; genae of head very long. 



4. loiigicollis. 

 Prothorax about as long as wide. 



Eyes small ; genae rather long ; form of body slender ; abdomen 

 narrow, rather rapidly narrowed toward the base. 



5. difiicilis. 

 Eyes larger ; genae much shorter ; form of body more robust ; 

 abdomen broader, just visibly narrowed toward the base. 



6. congener. 

 Prothorax distinctly wider than long. 



Pubescence very coarse, erect, and conspicuous ; antennae long 

 and very robust, strongly setose ; males having two elongate 

 spines protruding from beneath the third ventral segment ; 



size large ..- 7. sexiialis. 



Pubescence scarcely noticeable, very tine, short, and recumbent. 

 Head wider than long. 



Sides of prothorax broadly rounded throughout ; male having 

 two spines protruding from beneath the third ventral seg- 

 ment 8. spinifer. 



Sides of prothorax much more acutely rounded anteriorly, 



straight posteriorly 0. linearis. 



Head as long as wide 10. interruptiis. 



