42 ENTOMOLOGICAL SOCIETY 



recognition marks, differences in these points are properly of 

 specific value. The genus, if it is to have a meaning different 

 from species, must have a different basis. Neither should the 

 characters of species be grouped for the purpose of making 

 genera; the grouping of specific characters simply indicates 

 groups of species. It introduces no new idea to warrant the 

 new name, genus. Basing the genus on the characters of 

 species means reducing the genus in rank, and multiplying the 

 genera. Never yet did an author, basing genera on the charac 

 ters of species, fail to create a lot of new genera. 



Again, genera should not be based, as a rule, on a single 

 structural point, nor on two or more related points, such as 

 long wings and elongate cells. Rather should we seek for two 

 or more disassociated characters for the foundation of a genus. 



It is almost unnecessary to state that habits or coloration 

 should not be the distinguishing characters of a genus. 



The presence or absence of a structure is of more value 

 than the size or development of a common character. 



A character that has not been restricted to close limits within 

 the family is not of much use in the separation of genera in 

 that family. 



An extreme of a variable character should not distinguish 

 a genus. For example, if a cell in one genus of a family is 

 wide open, and more or less completely closed in various other 

 genera, its complete closure or even stylation ought not to be 

 the basis of a genus. 



Striking characters, noticeable at a glance, are rarely of 

 generic value; but minute points, especially when associated 

 with some habit, are of great use. 



Differences in the mouth-parts, in the legs and wings, are 

 preeminently of generic importance. The antennae and head 

 furnish also good generic structures; the rest of the body is 

 much less valuable in these respects. We should consider the 

 value of a character to the insect ; whether it is related to the 

 method of life. For example, a striking difference in shape 

 of the ovipositor indicates that the insect has a different method 

 or place of living from its allies, and we naturally expect to 

 find that such a form represents a genus, definable also by other 

 structures. 



