NORTH AMERICAN COI.KOTTKRA. :! 



After the scutellum the next most iniporraiit division is l)ase(l on 

 the arrangement of the spinules snrrounding the apex of tlie hind 

 tibise, whether equal or unequaL A little experience will enable one 

 to determine to Avhich series a species belongs even when the sjjinules 

 are worn to nearly an equal size. Any synoptic division beyond this 

 point is purely speculative ; for, whatever cliararter is used, there 

 will necessarily be an artificial result. 



Two characters to which attention is particularly directed by C. 

 G. Thomson (Skand. col. v) have been used in the following pages 

 with good results : (1) whether the anterior face of the front tibiae is 

 smooth or punctured, and (2) whether the first anterior tarsal joint 

 is of equal or greater lengtli or shorter than the second. Tlie length 

 of the first joint of the hind tarsus has also great value in separating 

 species otherwise closely allied. 



The carination of the mesosternum between the coxa? is ahvavs a 

 character of moment, altln)ugh at times it loses importance beyond 

 specific value, as in lentus, explanatus and inqiiinatus. 



The sexual characters of our species seem far more varied than in 

 the European forms. To dwell particularly on these at this time 

 seems unnecessary, as they are ftilly explained in their proper places, 

 and no special use is made of them in the tables. 



In accordance with the views expressed in the preceding remarks 

 it is pi'oposed to divide the genus A})hodius into the fi)ll()wing sub- 

 genera : 



Scutellmn Ions, one-fourth or one-fifth the length of the elyti-al suture. 

 Hind tibife fimbriate with equal spinules. 



Scutellum not impressed ; first joint of hind tarsus % simple; anterior tibiiv 



not serrulate above the teeth Subgen. Teuckkstes. 



Scutellum longitudinally impressed ; first joint of hind tarsus % with re- 

 current process; anterior tibife serrulate above the teeth. 



Subgen. Diaptkkxa. 

 Hind tibiffi fimbriate with unequal spinules; scutellum not impres.sed ; anterior 

 tibife feebly serrulate above the teeth ; hind tarsi % simple. 



Sul)gen. COLOBOPTERU,-*. 



Scutellum small, not more thati one-eighth orone-teuth the length of the suture ; 

 hind tarsi % sinii)le; characters otherwise very variable. 



Subgen. Ainionirs. 



Subgen. Teuchestes MhIs. 



Scutellum large, nearly one-fourth the length of the elytra. An- 

 terior tibiae tridentate, not serrulate above, the anterior face smooth, 

 the tarsus with the first joint shorter than the second. Posterior 



