282 BULLETIN OF THE MUSEUM OF COMPARATIVE ZOOLOGY. 



But assuming that both are at hand, — a very detailed knowledge and 

 a very complete collection, — it is obvious that at the present time both 

 can exist only for some specialty, and not for the whole class of insects. 

 Every attempt to go beyond those limits commonly entails errors 

 in a geometrical progression. Undoubtedly the smallest fragment of 

 an insect belonged to a species, to a genus, to a family. Nevertheless 

 it cannot be an advantage to science, it cannot mark a progress for sci- 

 ence, if such fragments are named and determined as a species, and as 

 possibly belonging to such and such a genus and family. It is evident 

 from the "insignificant fragment" of Dyscritus vetustiis, discussed at 

 length in page 22, that any scientific judgment, and therefore any scien- 

 tific classification of it is impossible. It can belong to several differ- 

 ent families, and it is quite as probable that it belongs to Platephemera, 

 or to Gerephemera, or to some entirely different insect. The fragment is 

 so insignificant, that, if the whole fauna of the Devonian Insects was 

 known, it would be impossible to ascertain its place with certainty. 

 Therefore such names are not only useless, but a hindrance to science. 

 Ten years ago the Rev. Jlr. Eaton, of Croydon,. England, expressed the 

 same opinion in strong terms; but Mr. Scudder (p. 11) objects to these 

 strictures in the most emphatic mannei", without giving any satisfactory 

 reasons. 



Palaeontological works are and can only be studied and understood in 

 our days Iw specialists, and for special groups. Others must take the 

 conclusions for granted, which they are not al)le to control, for want of 

 special knowledge. I must frankly declare that it is for the interest of 

 science that such nomenclature should be discontinued, as it is sure to 

 be with a little kuowled2;e of facts. 



Cambridge, March, 1881. 



