The Taconic — Marcou. 15 
A^alley, the Dudley observatory near Albany ; and such a good 
fossil-hunter as Mr. Walcott ought to have found many localities 
in Washington and Rensselaer counties, or in Berkshire, Ben- 
nington, Rutland, Addison, Chittenden and Franklin counties, 
where he indicates with such certainty the existence of vast sur- 
faces covered by the Hudson [Lorraine and Utica]. To be 
sure he has found there the Triarfhi'us beckU^n% determmed by 
Mr. J. Hall, and endorsed as exact by him in 1S79; o'llv he has 
come to the conclusion, in iSS6,that the Triai-thrus [ Calymeiie'^ 
beckii of Washington county was not that species, not even that 
genus, and he has been obliged to refer it, not to Atops trili- 
ncatiis of Emmons, but still to regard it as a primordial fossil. 
The negative result of the researches of Mr. Walcott in the 
Taconic area for discovering the beautiful Utica fauna of Dud- 
ley observatory is of great importance. As such a fauna was 
never found in the slates and shales of Canada, identified by 
the adversaries of the Taconic, first with the Utica-Lorraine 
group, and afterward referred to the Quebec group, Dudley 
observatory is an exception, not in regard to the fauna, but only 
in regard to the three graptolites, on which I shall return fur- 
ther on, when I shall treat of the stratigraphj- and lithology. 
There is however one j^artof the graptolite question on which 
Mr. Walcott has neglected to instruct us; it is, whether those 
three graptolites [ C bico7'nis, D. rainosKs and D. imicronatus'^ 
have been found ever in the Utica slate at Utica, or any other 
localities west of Albany and Dudley observatory, or in the 
typical localities of the Lorraine shales in Lewis and Jefferson 
counties, N. Y. 
Fossils ov the eastern quartzytes. For many years 
the eastern quartzytes of the Taconic area have been known to 
contain a few fossils. Messrs. Hall and Dana have determined 
a Lingula^ related to a species in the Medina sandstone [upper 
Silurian], many casts of one valve of a so-called Modiolopsis., 
and an Orthoceras^ indicating according to their views, more 
•especially the Lamellibranchia, that "the eastern quartzyte for- 
mation is of the age of the later Trenton, or Cincinnati group." 
S^Amer. Jourii. ScL, vol. xiv, p. 207, 1877.] Mr. Walcott does 
not refer in any way to the Lingula^ except to say that "Prof. 
H. S. vSeely had traced the Rockville Li)igula to a boulder." 
