Bules and Misrules in C lass ijicat ion. — Marcoii. 45 
phenomenon of mixture of forms of the primordial and sec- 
ond faunas as exists in Wales, and in England in the Trema- 
doc group and the Arenig or Skiddau group, and at Hoif in 
Bavaria. It is important to recall that the Geological Survey 
of Great Britain, conducted by Sir Andrew C. Ramsay, found 
during 1875 that fossils passed from the Tremadoc into the 
Arenig, ten or eleven species, according to Etheridge, the 
paheontologist of the surve}^ and that between the Arenig 
and the Caradf)C beds (true Ordovician or second fauna) 
eight species also passed, showing beyond any doubt that 
species are no more immutable in their position of strata in 
Europe than in America. 
As far back as 1862. the present writer divided the Upper 
Taconic into three parts, calling the lower part Pointe Levis 
or Phillipsburgh group, with a thickness of 3,000 feet; then 
the middle part called Swanton slates or City of Quebec group, 
thickness, 2,400 feet ; and finally the Potsdam sandstone, three 
hundred feet. Everything published since, by friends and 
opponents of the Taconic system, has proved the litness and 
value of that definition; only it is very hard for those who 
are accustomed to call Calciferous formation, Chazy, Black 
River, Trenton, and Hudson River groups, all the outcrops of 
some islets isolated among the black slates of the Taconic, 
containing a few fossils, recalling, in a small scale, those for- 
mations, to accept their mistake, preferring to pass over and 
neglect all stratigrapliical, lithological and even paheontolog- 
ical rules. Of course they are involved in an ocean of difficul- 
ties, but nothing stops them, and they hope, with proper use of 
faults — even when faults cannot be seen — and diiferent facies 
and thickness of formations to explain, satisfactorily at least 
to themselves, that the Phillipsburgh series belongs to the 
Calciferous formation and the Quebec City or Swanton 
slate series, in part, to the Chazy, Black River, and Trenton, 
and even in some part to the Hudson River (Utica and Lor- 
raine shales), the most heterogenous mixture and chaotic clas- 
sification that it is possible to imagine. Some quotations of 
some of the last classification used by some observers, will 
give an idea of the confusion brought about by misrules. 
