[61] NORTH AMERICAN COLEOPTERA. 217 



ing to the ligula, which organ is here, in opposition to the 

 general rule, tricuspid at the apex. Many representatives 

 having the tricuspid ligula arc found in America, and as 

 they are all small and generally possess some of the char- 

 acteristics of Scopgeus, such as the narrow neck, they have 

 been assigned to that genus without due consideration. 

 Upon examination these various forms are found to differ 

 considerably in structure, so much so in fact that the desir- 

 ability aud propriety of generically separating them can 

 no longer be doubted; several of the more markedly distinct 

 groups have already been noticed. Diagnoses of the genera 

 which inhabit the United States, may be stated as follows: — 



Posterior angle of prosternum prominent, the lower edge of the intercoxal 

 lamiua being reentrant or inwardly arcuate at and near its vertex and not 

 longitudinally continuous in curvature with the prosternum. Anterior 

 angles of prothorax very broadly rounded or obsolete. 



Posterior under side-pieces of pronotum well developed. Surface punctate 

 or alutaceous Scopseus. 



Posterior under side-pieces rudimentary. Surface polished aud nearly irn- 



punctate throughout Scopseodera. 



Posterior angle of prosternum not prominent, the lower edge of the inter- 

 coxal lamina being outwardly arcuate at and near the angle and longitu- 

 dinally continuous in curvature with the prosternum. Anterior angles 

 of the prothorax more or less prominent. Posterior under side-pieces 

 of the pronotum rather well developed. 



Neck very slender; integuments excessively minutely punctate, aluta- 

 ceous Leptorus. 



Neck broader; integuments coarsely punctate, polished Orus- 



The generic characters of Scopreus have been taken from 

 a typical representative of S. Icevigatus Gyll., for which I 

 am indebted to M. A. Salle'. 



SCOPJEUS Erichs. 



Several American species are assignable to this genus, 

 among others opacus Lee. The following species of the 

 Pacific Coast may also be placed here at present. 



S. rotlindiceps "• S P- — Rather slender, black; legs castaneous, paler toward 

 tip; antenua) and palpi rufo-fuscous, the former paler and flavate at the apex; 

 pubescence fine, short, very dense, more sparse on the pronotum, most conspic- 



