244 The Taconic Question Restated. [March 
lites of Pointe Levis, which were then described as belonging to _ 
a higher horizon than the Utica slate, and in the words of Hall 
to “that part of the Hudson River group which is sometimes 
designated as Eaton’s Sparry limestone,—being near the summit 
of the group.” Still later, in 1859, with regard to the trilobitic 
‘strata of the town of Georgia, Vermont (the “slates with Para- 
doxides” of Emmons, noticed in § 19), Hall wrote, “I have the 
testimony of Sir William Logan that the shales of this locality 
are in the upper part of the Hudson River group, or form part 
ofa series of strata which he is inclined to rank as a distinct 
group above the Hudson River proper.” 
§ 22. It was in 1856 that the finding by the present writer of 
an unknown trilobite in one of the many limestone bands of this 
Graywacke series at Pointe Levis, opposite the city of Quebec, 
led to further researches, revealing in that series a fauna which 
furnished to Billings convincing proof that the view of Eaton 
and Emmons was the correct one, and that this same Graywacke, 
or Hudson River group, was below and not above the horizon of 
the Trenton limestone, and was in fact the First and not the 
Second Graywacke of Eaton. This was first admitted by Logan 
in a letter to Barrande, dated December 31, 1860, but published 
in 1861." In this, referring to the trilobitic beds in Vermont 
noticed above, which he had placed at the summit of the Hudson 
River group, but now declares that he had “ recognized as equiv- 
alent to the magnesian part of the Quebec group,’ Logan 
writes, “ Prof. Emmons has long maintained, on evidence that has 
been much disputed,” that these rocks “are older than the Birds- 
eye formation” (the basal beds of the Trenton), and adds, “ the 
fossils which have this year been obtained at Quebec pretty 
clearly demonstrate that in this he is right.” 
Refusing, however, to adopt the name of Upper Taconic or 
that of the First Graywacke, Logan, for reasons of his own, chose 
to give to these rocks the title of the Quebec group, a name 
which he extended to the whole belt from the Lower St. Law- 
rence to the valley of the Hudson River, and henceforth made 
no further allusion to Emmons, whose views he had now 
adopted. In accordance with the teachings of Emmons in 1846 
and 1855, these rocks were now declared by Logan to be a great 
sad eee of sediments about the age of the Chazy and the 
* American Journal of Science, xxxi. 220. 
La 
