AMERICAN COLEOPTERA. 155 



genera very closely and naturally allied, but the definition of these groups 

 is very artificial and we find already a great number of odd genera thrown 

 aside which will not fit in any tribe he has proposed and which must of 

 necessity form groups by themselves. Such a minute subdivision is con- 

 fusing but would be excusable and even acceptable if the characters on 

 which it is founded were even moderately constant, but with the few 

 genera which occur in our fauna I can say that no characters exist in the 

 ligula which can be used to divide the tribe into groups. 



In the accompanying table the characters seem hardly to warrant any 

 further explanation. Attention might be directed to the very long tibial 

 spurs of Tetragonodeinis and Nemotarsus, in the former genus their edges 

 are finely serrulate a remarkable character in the present family and one 

 which is by no means common in Coleoptera generally. 



In Fentagonica (Rhombodera) which in its form occupies an inter- 

 mediate position between Lehia (Aphelogenia) and Eucxrus the mandi- 

 bles are without scrobes, that is they are deprived of that triangular 

 groove on the outer side so commonly present in the Carabidae. The 

 mandibles here recall those of Loricera or Leistus although the lower 

 edge is less expanded than in these two genera. 



To the present tribe and in close association with Tetragonoderia;, Chau- 

 doir has added C'^closomus a curious genus of a form and aspect closely 

 resembling Omophron, it is however correctly placed by that author. 



Eucserus which will be found in one of the extremes of the following 

 table is one of those unfortunate genera which has never been allowed to 

 remain- for any length of time in any one position. At its beginning it 

 was placed «ear the Harpali, thence (Class. Col. N. A. p. 22), it was 

 removed and made part of a rather composite tribe and placed near the 

 Lachnophori. Chaudoir accepts this view. While it is doubtless an 

 o.sculaut form it seems to me more nearly allied to the present series 

 than to Lachnophorua. 



The maxillae present a few variations from the usual fixed type and 

 attention is directed to the fignires of Tetragonoderus, Eucserus and 

 Pinacodera. 



The antennae are very constant in their pubescence. In the vast 

 majority of species the three basal joints and the adjacent half of the 

 fourth are glabrous, but in Phloeoxena four joints are smooth while in 

 Eucserus the third is pubescent and the second scarcely less so. 



The genera below are those known at present in our fauna. To have 

 introduced those exotic genera known to me would not have been a 

 difficult task, but it seemed to me to be unnecessary as very nearly if 



