THE 
AMERICAN GEOLOGIST 
Vol. II. AUGUST, :888. No. 2. 
PALiEONTOLOGIC AND STRATIGRAPHIC "PRINCIPLES" 
OF THE ADVERSARIES OF THE TACONIC. 
BY JULES MARCOU. 
II. 
Mr. WaLCOTt's STRATIGRAPHY AND NOMENCLATURE OF 
THE Taconic area. — I shall briefly notice the different groups 
of strata called numbers, i, 2, 3, 4, 5, and 6, by Mr. Walcott. 
No I, or quartzyte series, or granular quartz, is the oldest of 
the sediments known on the eastern side of the Taconic area. 
The fauna correlates it with the Taconic of Georgia, but accord- 
ing to Mr. Walcott not so low in position as the fauna of the 
lower strata of the Georgia slates, an opinion which requires 
confirmation. No thickness is given. Mr. Walcott disagrees 
with his associates Messrs. Dana, Hall and Hitchcock as to the 
age of No. i. 
No. 2 formed of "h3'dromica slates" on the section of Mr» 
Walcott, is assumed to represent the Potsdam sandstone. No 
fossils there. Thickness 2,000 feet. Mr. Walcott is rather ob- 
scure, saying, that "to the east of the limestone (of the Taconic 
Georgia), the Potsdam may be represented in part by either 
( I ) the upper part of the quartzyte No i ; (2) the lower part of 
.the limestone of No. 3 (C. C. T.,) or (3) the hydromica shale 
between the quartzyte and limestone or No. 2 ; or by a combina- 
tion of two or more of these parts." Finally Mr. Walcott regards 
No. 2 as the Potsdam off shore originally deposited as a calcareous 
or argillaceous mud. Only in the eastern Taconic area, the 
deposit is as near the shore as that round the Adirondacks,and not 
at all an "off-shore deposit," as Mr. Walcott wants to make it. 
There is no proof whatever that No. 2 is the Potsdam sand- 
stone and its identification by Mr. Walcott is made against all 
