110 AMERICAN COLEOPTERA. 



diiference in the claws — these being strongly toothed in the female 

 and nearly simple in the male — a fact peculiar in itself, and one 

 which is not mentioned in any European literature to which I have 

 had access. 



While the form of the claws as a pi'imary means of division does 

 not, I am sure, result in a perfectly natural arrangement, there 

 would ajipear to be no other which can be so satisfactorily used, 

 and the few species which now seem out of place will have to wait 

 until a more rational scheme can l)e devised. 



I have endeavored to make the descriptions following as full as 

 need be in all essential matters, without rendering them unnecessarily 

 prolix by the introduction of a mass of details, which are either so 

 constant in large numbers of species, or so subject to individual 

 variation as to serve no useful purpose. In measurement of length 

 the beak is always excluded. By the dilation of the beak is always 

 meant the expansion over the insertion of the antennse as seen from 

 above. The term mucronate has been uniforndy used in referring to 

 the armature of the male tibiae, though it is possible that the term 

 unguiculate would have been more appropritate in some instances. 



Following lines already indicated, our species are primarily divi- 

 ded into four secticms, as follows : 



Claws simple or nearly so. 



Anterior femora of tlie % more or less swollen or tnberculate and with a 

 polished area toward the tip I. 



Anterior femora of %, unmodified II. 



Claws evidently toothed near the base. 



Tibiae of 'J, wholly or iu part mucronate at tip. III. 



Tibise of % unarmed at tip. IV. 



A few of the species in Section II have the claws of such a shape 

 as to occasion .some doubt as to the series in which they should be 

 placed; should the student fail to locate his species in the series 

 with toothed claws, he would do well to revert to Section II before 

 giving up the search. 



I. 



The members of this series form a natural group, probably of 

 subgeneric value, and, so far as known, peculiar to our fauna. In 

 general facies certain species are in a few instances rather closely 

 paralleled by members of one or another of the other sections ; from 

 all these, however, the sexual characters sharply separate them. 

 The form is generally slender, the pubescence sparse or nearly 



