234 



Micros, \'ol. II, ]i. Z2.\ 1918) of two I'frprcssaria from Colorado. 

 Everybody knows that iIktu are additional undescribed species of 

 Dcprcssaria in Colorado and the merest beginner can easily describe 

 such from stray specimens in his possession ; such descriptions how- 

 ever are not advancing our knowledge, but retarding it. It is impos- 

 sible to determine such a species with certainty from even the best 

 description in a group of so many and so closely similar species as 

 Agotiopteryx and Dcprcssaria, at least not without a most careful 

 figure of the moth and its genitalia, and our exact knowledge of such 

 insect is therefore suspended until someone can go to England and 

 compare specimens with the unicjue type in !\lr. Meyrick's private 

 collection. 



This kind of work was excusable and even defensible fifty years 

 ago, when the American fauna was little known and when every au- 

 thorative determination extended our knowledge of geographical dis- 

 tribution, if nothing more. It may again become of value, when the 

 fauna eventually shall be so well known as it is in Europe, when any 

 deviating variety described can easily be recognized and assigned to 

 its proper position as species or variety as the case may be, but at the 

 present time, when we are struggling with many as yet unrecognized 

 described species and are trying to acquire sound knowledge of our 

 fauna through the collection of large series and careful breeding, any 

 stray description from "Colorado, 7000 feet, one specimen," is a hind- 

 rance pure and simple to our knowledge, not an advance as a descrip- 

 tion should be. 



Colorado has an area of over 100,000 square miles, more than 

 England and .Scotland together, and it has a thousand ditTerent locali- 

 ties of 7000 feet altitude. Mow would Mr. Meyrick consider a locality 

 for a new species given as ; Great Britain, without indication whether 

 it came from Cornwall or Aberdeen ? It is a regrettable fact that the 

 most of the "unrecognized" species in our American lists and empty 

 spaces in our American collections are no longer those of Chambers, 

 whose many insufficiently described species hitherto have been our 

 main difficulty, but are those of our eminent colleague in England, 

 whose genius and indefatigable diligence has advanced the knowledge 

 of the world's inicro-fauna more than any other past or present worker 

 and to whom the American student otherwise is greatly indebted for 

 his continued liberal assistance. 



