4 Introduction 



As a preliminary matter it may be well to recall that the classifica- 

 tion of the Coleoptera has been frequently altered. In our own country 

 the following catalogues have appeared: 



F. V. Melsheimer 1806 



F. E. Melsheimer 1853 

 J. L. Leconte 1863 



G. R. Crotch 1873 and E. P. Austin, Supplement, 1880. 

 Samuel Henshaw 1885 and Supplement, 1895. 



There is no agreement in the sequence of famihes in these American 

 catalogues, nor do they agree with those published abroad, which also 

 differ among themselves. The reason is that each is based upon a differ- 

 ent stage in the ever-changing system of classification. 



Systems formerly in Use 



The earhest system employing binomial nomenclature is of course 

 that of Linne's, ed. X, 1758. In that work, the beetles (with a few 

 insects no longer considered beetles) are divided into three groups, 

 according to the form of the antennae, "clavatis," " filif ormibus " and 

 "setaceis." 



Many other attempts (among wliich Latreille's recognition of the 

 different forms of the outer maxillary lobe, by which he separated what 

 he called beetles with six palpi from those with four palpi, is noteworthy) 

 led up to the system developed by Latreille, Erichson, Lacordaire, Duval 

 and other great coleopterists. This system was in use when Dr. Leconte 

 began his studies; it had then long held sway and has profoundly in- 

 fluenced him and all the writers on Coleoptera even to this day. It 

 attempts to classify beetles primarily by the number of their tarsal 

 joints, thus: 



Pentamera — beetles with all the tarsi 5-jointed. 



Teteamera — " " " " " 4 « 



Trimera — " " " " " 3 " 



Hbteromera — " " front and middle tarsi 5-jointed, hind tarsi 4-iointed. 



The existence of minute joints, difficult to see but actually present, 

 necessitated the use of terms like pseudotetramera and cryptote- 

 tramera. Such a classification, unless qualified by many exceptions, 

 leads to the most unnatural aggregations and is now practically 

 discarded, except that Heteromera are retained by many modern au- 

 thors as a natural series.^ I beUeve that it is an unfortunate retention, 



' The families (or part of them) usually included in Heteromera may truly constitute a natural 

 series, l)ut, if so, it cannot be safely defined by the heteromerous tarsi. 



