1887] Notes on Classification and Nomenclature. 1 0oy 
was first used by him in a geological article dated January 27, 
1819. Lee, Hitchcock, Emmons, Dewey, Barnes, Briggs, and 
Eaton, between 1819 and 1842, frequently use the term in their 
geological papers. They considered the rocks extending from 
the western towns of Vermont and Massachusetts westward to 
the Hudson River as constituting a group different from those 
farther east, and set off by geological distinctions so markedly 
that they could not be confounded. Sometimes these rocks 
were referred to as the rocks of the Taconic range, sometimes as 
transition rocks, and sometimes as the metamorphic group, But 
that they were a single group, e» masse, was not questioned, 
either by the friends or the opponents of the Taconic system, as 
late as 1844, Eaton having gone so far as to place them below 
the strata of the New York system. 
Used, then, as a datum of geological reckoning, “ the rocks of 
the Taconic range” date from 1819, but it was not till 1842 that 
Dr. Emmons erected these into a geological group and formally 
announced the “ Taconic System.” 
The foregoing facts may be tabulated as below : 
Used asa Faunal Used in Geological Used as Name ofa 
ature. Zo 
Designation. Liter: ne or System. 
aA O Sie oss kas 1846 1846 1846 
x Cambrian 1853 .1836 1836 
Taconic 1844 1819 1842 
In thus calling attention to the use of the term Taconic in 
geological literature as early as 1819, the objection will naturally 
arise in the minds: of some of the committee that the term was 
used wholly as a geographic and not as a geological one, and 
hence that it has no claim in geological nomenclature. While 
ere is some force in this objection, yet, if the nature of the 
Papers written by the earlier geologists be examined into, it will 
be Seen at once that the term was used both in a geographic and 
‘Ma geological sense. Professor Dewey, in 1820, giving his 
Seological section from the Taconic range to Troy, N. Y., says dis- 
tinctly that the same rock-formation which constitutes the range 
at Williamstown extends to the Hoosac Valley, and gives place 
to a chlorite slate, which, since it is also found in the Taconic 
_ Tange, “ ought to be considered as belonging to the range, and © 
as the rock into which the talcose slate passes.” From here he 
Continues the section through graywacke rising into the hills at 
