classification of the Tincina. 131 



their classification should be firmly established on solid 

 principles. It is impossible to condemn too strongly the 

 worthless character of the work done by those who 

 create new genera at random, locate species by their 

 superficial appearance, making a mere pretence of 

 structural diagnosis, and frequently refer specimens of 

 the same species to different genera, and even to different 

 families, on account of slight differences in colour and 

 shape of wing. It can hardly be expected that scientific 

 investigators of the present day will acquiesce in the 

 methods and results of writers who still continue to 

 classify on the lines of Francis Walker. I am disposed 

 to think that since, at the present time, a specific de- 

 scription is not only worthless, but also practically 

 unidentifiable, unless accompanied by a full statement 

 of the true generic characters, it may and should be 

 as justly disregarded as though it were non-existent. 



