1898.] GROTE — SPECIALIZATIONS OF LEPIDOPTEROUS WING. 19 



pupae, where exactly what is meant by the terms ^'Satyrus, Epine- 

 phele, Hipparchia," does not appear {Entom. Record, vi, 152). So 

 far as the diurnals are concerned the authority I recognize is Mr. 

 Scudder's Historical Sketch, Salem, 1875. Since, in exceptional 

 cases, this work has been seemingly properly corrected and even in 

 one case by the author himself, a republication up to date would be 

 one of the most grateful of literary helps to the systematist, to whom 

 it is a matter of comparative indifference what term he uses so that it 

 is correct and exactly conveys his meaning, while it should be one 

 necessarily understood. Since the difference between genera and spe- 

 cies is quantitative, the limitations of the former will be always more 

 or less a matter of opinion. As matters are now and unless a standard 

 is recognized, the object of nomenclature will be defeated so far as 

 generic titles used by themselves are concerned. Both to give 

 greater endurance to his work and to make it a useful addition to 

 generic definitions extant in literature, the systematist might confine 

 his studies to species used for generic types as far as possible and 

 neglect those not yet so favored. To locate and compare genera 

 their types need alone be considered ; by clearly explaining the 

 structure of these incidental help will be afforded to reach an 

 approximative agreement as to the limitation of generic groups. 

 Generic terms should always have the same meaning attached to 

 them, and this meaning can only be derived from the structure of 

 their types. I remember that Moeschler, disputing the validity of 

 the genera allied to Smerinthus and wishing to discredit minute 

 generic differentiation, asked triumphantly. To what genus, then, do 

 the hybrids between species belonging to these different allied 

 genera belong? A little reflection might have led him to ask the 

 question also. And to what species ? For although, to Moeschler, a 

 genus would seem to have constituted a fixed quality, yet it is seen 

 not to be so and that the genus idea is an extension of the species 

 idea, and both ideal categories having a relative being without sharp 

 outlines. In the formation of generic categories the idiosyncrasy 

 of the describer comes easier to the surface, as in Mr. Scudder's 

 genera ; but for the purposes of the systematist these are as good as 

 any, and better than most ; all that is wanted being a certain name 

 attached to a certain thing. The describers of species are the avant 

 couriers of the systematists, one no more useful than the other, and 

 any adverse criticism of the former class, who throw the first light 

 upon our darkness, must be due to a lack of thought and considera- 



