STAPHYLINID^E. 3 



genera which differ among themselves only in sexual modifications 

 at the ventral apex, though often most important if supplemented 

 by structural differences elsewhere, on the other hand, is eminently 

 proper. And, after all, what is to be gained by trying to aggregate 

 these structural groups of species under a single name, as in the case 

 of the comprehensive genus Atheta of the most recent school? Not 

 only is there no discernible advantage in this procedure, but we 

 subject ourselves to very great inconvenience in efforts to prevent 

 duplication of specific names in such enormous single genera. This 

 difficulty is also becoming pronounced in Stenus, but there it seems 

 impossible to suggest the relief afforded by generic subdivision, 

 which is so proper in Atheta because of the widely diversified facies 

 as well as structure prevailing in the latter group; in Stenns the 

 facies is very consistent throughout, and most of the subdivisions 

 that have been proposed are apparently not true genera from any 

 reasonable point of view. The European catalogue of Heyden, 

 Reitter and Weise of 1895 ' ls f ar superior to that of 1906, not only 

 in its more sensible treatment of the Atheta?, as being composed of 

 at least a few admittedly valid genera, but especially because our 

 sense of propriety is not offended by the wholly unnecessary reversal 

 of the usual succession of subfamilies, tribes and genera in the 

 great family Staphylinidse given in the latest edition of that work. 



Another mistake frequently made, and a very serious one, is in 

 assuming that nearly all exotic forms can be forced into the genera 

 of purely European species. Some genera are common to Europe 

 and America, but the isolation of the latter region since the middle 

 Tertiary has sufficed for the evolution of many distinct types, so 

 that at present there are a great many more endemic American 

 genera than of those common to the two continents. The same 

 remark applies as well to the species, the least resemblance between 

 species of the two continents sufficing some superficial observers 

 for a verdict of identity, which is false as a rule. There are some 

 species common to America and Europe but not many, and they 

 constitute an exceedingly small proportion of the whole number 

 known; moreover virtually all such are likely to be cosmopolitan. 



There have been but few attempts ever made to systematically 

 arrange the genera and subgenera of Athetae in accordance with 

 their structural differences, and I would here bring forward one 



