20 'The Taconic — Marcou. 
Menoccphalus^ Conoccphalitcs, Agnostus and Camcrclla., ctc^ 
In his two papers: '■'■Sur les colonies 'dans les roches taconiques 
etc., 1881," and '■.'■The Taconic system and its position etc — 
1885," Marcou gives his reasons and proofs for placing in the 
Taconic, all the sporadic species of the second fauna; identified 
as existing in the upper primordial; a very small number — a 
dozen at most — and he shows that such a mixture of forms and 
species of the second fauna, with forms of the first fauna exists 
and even on a greater scale, in Bavaria, Norway, Sweden and in 
Wales. These conclusions of Marcou, explain all the confusion 
and errors arrived at by the adversaries of the Taconic, in 
the original Taconic area. To be sure they differ also from 
Dr. Emmons views in a few minor points, where Dr. Emmons 
thought that he had found Calciferous, Chazy and Trenton lay- 
ers of limestone, resting in discordance of stratification above the 
Taconic slate. A few words and quotations will show the dif- 
ference and clear up the question, which has been such a 
stumbling block to all the observers. 
Explanation of the fossiliferous limestone inclosei> 
IN THE Taconic slates. Dr. Emmons found, inclosed in the 
great mass of slates of the Taconic system, limestones scattered 
almost all through the area, from the vicinity of Williamstown 
to Troy; and north and south of that line. He rightly classified 
in the Taconic system the Stockbridge and Sparry limestones; 
only owing to the special area where he studied them, [Berk- 
shire, Columbia, Rensselaer, Bennington and Washington coun- 
ties,] he finds them directly super-posed and in concordance of 
stratification on the granular quartz, and he thought that they 
succeeded them in the tabular classification and index of the 
Taconic strata. He was misled by a stratigraphical accident, 
which is not rare in great mountainous countries like the Alps, 
the Jura or the Pyrenees; or in any very distorted mass of old 
strata, as in Britanny and in the Cantabrian mountains of Spain. 
At the initial points of dislocation and upheaval, near the centre 
of the ranges, the main part of the lower strata are concealed 
^se derobe7it'\^ being replaced by the upper part of the broken 
up and folded system of strata, lying in concordance of stratifi- 
cation on the base of the formation; the concordance being a 
result of folding, stretching and sliding. 
