140 PRIMORDIAL—WAPPINGER LIMESTONES. 
a connecting iink between the known fossi!s of the Ap- 
palachian region and those of the western states. Thus 
with the Lingulepis minima and L. acuminata of the 
New York Potsdam is found the Lingulepis pinni- 
formis of Wisconsin and other western localities. 
It may also be remarked that the fauna of the Pough- 
keepsie locality, as far as at present developed, is quite 
distinct from that of the Potsdam strata recently dis- 
covered by Mr. 8S. W. Ford at Schodack Landing and 
other places in the town of Stuyvesant, N. Y. From 
these localities, lying about fifty miles north of Pough- 
keepsie, Mr. Ford reports the following eleven species : 
Paleophycus incipiens, Obolella crassa, Stenotheca 
rugosa, Hyolithes americanus, H. impar, Hyolithellus 
micans, Microdiscus lobatus, M. speciosus, Conocoryphe 
trilineata, Olenellus asaphoides, and Fordilla troyensis. 
No one of the above list has been found at Pough- 
keepsie; the distinctive character of the two faune is 
evident, the latter apparently representing an earlier 
stage of life. 
The discovery of the presence of fossiliferous Primor- 
dial rocks among the Wappinger valley limestones 
while it adds an extremely interesting feature to the 
geology of the region, contributes another complication 
to the difficult task of mastering the stratigraphy of 
Dutchess county. 
Norr.— Since the above paper was written I have conducted these researches further, 
and have traced the continuation southerly of the fault between the Potsdam and Hudson 
river shale to the bank of the Hudson river. This line, which had been traced previously . 
only into W. S. Johnsion’s farm, has been found to continue, well marked as before by 
ponds and gullies, in a straight line till it crosses the Albany post road at the corner of the 
New Hackensack road near school house No. 2. On the west side of the post road it 
passes straight across R. T. Gill’s farm, then crossing the road leading to the Milton ferry, 
and striking between the two roads leading in a southwesterly direction to the river. It 
terminates finally in a high bluff on the river near Mallory’s moulding-sand dock and about 
one mile north of Clinton point post office. Throughout this course the Primordial lime- - 
stone and the shales show themselves frequently in close proximity in outcrops. In Gill’s 
farm both formations are mostly covered by hills of drift, but on this farm, just north of 
the Milton ferry road, both the Potsdam limestone (here as calcareous shale) and the Hud- 
son river shales crop out distinctly. The latter yield at this locality some very excellent 
24 
