L. F Ward — Fossil Dicotyledonous Leaves. 373 



that Heer and others have gone much too far in this direction, 

 and he points especially to recent "determinations" by Ettings- 

 hausen of specimens from Australia (Denkschr. Wien. Akad. 

 Bd. xlvii) and pronounces them worthless. And in this latter 

 case, when we remember what important deductions relative to 

 the character and distribution of the Tertiary flora are based 

 upon these identifications in the same paper in which they are 

 figured, we can scarcely complain that this criticism is too 

 severe. 



The remedy proposed by Dr. Nathorst for this state of things 

 is the adoption of a new system of nomenclature. He lays 

 down the rule that the generic name of a fossil leaf should in- 

 dicate just what we know about it and neither more nor less. 

 To call such leaves by the names of living genera is to say 

 more about them than we know. To obviate this he proposes 

 to employ composite names consisting of the name of the nearest 

 living genus with the suffix phyllum, the first component of 

 which will indicate the supposed relationship while the last will 

 denote that the genus is founded on leaves only. 



In addition to this Dr. JSTathorst makes three other important 

 recommendations, to which, however, very little objection will 

 probably be raised. The first is that where leaf-impressions, 

 apparently belonging to the same species, though differing 

 slightly, are found in widely separated localities, the trinomial 

 system be employed but without the abbreviation var., which, 

 as he justly remarks, implies that the one is a variety of the 

 other, a statement which we have no right to make. 



The second is that in all cases the types be carefully and 

 thoroughly figured, so that even those who cannot see the orig- 

 inal, can form a correct idea of their nature. To this end the 

 surface and consistency of the leaf should be represented as 

 accurately as possible, and the nervation should be shown even 

 to the finest meshes, at least on some small part of the leaf, to 

 indicate its true character. Mere contour lines are wholly in- 

 adequate for the determination of fossil leaves. 



The third of these recommendations is that unless the speci- 

 mens show good characters which admit of delineation and 

 description they be regarded as indeterminable and no attempt 

 be made to treat them as genera and species until better mate- 

 rial is obtained. 



Dr. Nathorst's paper concludes with an appeal to his co- 

 laborers in phytopaleontology to unite with him in securing 

 the adoption of these standards. 



In seriously considering these demands it is necessary to re- 

 member that we have a certain state of things to deal with 

 which is the product of a slow growth. Those who will most 

 readily admit that the system of nomenclature proposed is 



