1887] Notes on Classification and Nomenclature. 699 
In respect to Mr. Sedgwick, he worked on a series of rocks 
which he thought pertained to a single system, and illustrated 
it by fossils. These proved to be, for the most part, species of 
the Bala group, consisting of the second fauna. What few pri- 
mordial fossils he found he placed within the same fauna. He 
claimed this fauna and this system of rocks as his Cambrian. 
This was named in 1836. It was no error of his that subse- 
quently his term was crowded downward and removed from the 
rocks of the second fauna, and made to cover only a fauna of 
which he knew nothing. In other words, the author of the 
Cambrian intended to include in his system only the rocks contain- 
ing the second fauna. Still, his stratigraphic scheme embraced 
lower beds. 
In respect to the intention of Mr. Emmons, he worked on 
a series of rocks which he claimed was lower than the New 
York system. He announced a fauna which he intended to 
illustrate his system. The strata which he included in his sys- 
tem have been proved to contain his alleged fossils, and they 
pertain to a horizon below the New York system. All rocks 
known by him to contain fossils of the second fauna occurring 
within the general Taconic area were exempted by him from the 
Taconic system. His main intention, both stratigraphic and pala- 
ontologic, therefore, was to include the rocks of the primordial fauna 
in his system. 
On the question of priority, therefore, the inquiry is reduced 
to the conflict between Cambrian and Taconic, with the Taconic 
having two counts to the Cambrian one. 
On the question of the relative validity of those counts, the 
Taconic has that of correctness of palzontological identification 
and that of use in geological literature, which are very strong, 
While the Cambrian has that of formal announcement as a 
System. 
On the question of the intention and claim of the author, the 
Taconic was correct in stratigraphy and paleontology when ap- | 
Plied to the frst fauna, and incorrect when applied by its adver- 
saries to the second fauna. The Cambrian was correct in palæ- 
Ontology, and was not corrected by its author in stratigraphy ~ 
when applied to the second fauna, and is incorrect in both re- 
Spects when applied by its friends to the first fauna. | 
If the errors be eliminated, on each side, the first fauna should 
