L. F. Ward — Fossil Dicotyledonous Leaves. 375 



require the substitution for^these terminations, of the new one 

 phyllum. This would complicate matters, for many such 

 genera have already been changed, and not a few are still in 

 dispute, some authors treating them as identical with living 

 genera. Schimper undertook to change all names in ties to ides, 

 from considerations of etymological exactness, but he found 

 such a trifling change as this so difficult that he abandoned it 

 after the first volume, and in at least one case even then it had 

 led to the introduction and separate description of the same 

 genus twice (Paleontologie Vegetale, vol. i, p. 579, Danaaites, 

 Gopp., p. 616, Daneeides, Sch.). I mention these points in no 

 spirit of cavil, but merely to illustrate with what practical diffi- 

 culties any change in nomenclature is necessarily attended. 



With at least one of the minor suggestions of this highly 

 suggestive paper I think I can say without further reflection, 

 and from my personal experience with the cases involved, that 

 I do not agree. The writer correctly perceives that in many 

 cases where the material according to his strict canons is inde- 

 terminable it may still be important to figure what we have in 

 order to secure more general study and comparison, and he 

 also, as I think, justly condemns the reference of all such 

 cases to the meaningless (" nichtssagende ") genus Phyllites, but I 

 cannot go with him to the further length of recommending that 

 these objects after having been described and figured be left 

 entirely without names. We have thousands of such cases 

 now and they are becoming very troublesome in the literature 

 of the science. Names are useful however intrinsically mean- 

 ingless, in enabling us to refer to the objects named and to find 

 them when, we want them ; and anything that is worth figuring 

 is worth naming. I would therefore treat such cases like the 

 rest, and make provisional genera for them according to the 

 same rules by which they are made for better preserved mate- 

 rial. In practice there will be found to be no clear line of 

 demarcation between determinable and indeterminable material, 

 but a broad belt will exist over which it will be the one or the 

 other according to the views of different investigators. And if 

 it be said that these genera will mostly have to be abandoned, 

 thus encumbering the books, the reply is that the path of this, 

 as of every other branch of paleontology, is strewn with 

 abandoned names which all served a useful purpose in their day. 

 Moreover, what Dr. Nathorst has the courage to say relative to 

 species, viz : that notwithstanding the popular opposition to 

 multiplying species, the union of two impressions which do 

 not belong together works more mischief than the separation 

 of two that do belong together, will apply to genera as well as 

 to species, and the dropping out of these provisional genera as 

 their true affinities are ascertained will be attended with com- 

 paratively slight disturbance. 



