Oceanic Current in the Utica Epoch. — Ruedeiiiann. 79 
pebbles at Wellstown and at Ingham's Mills consist only of 
limestone, and not of crystalline rocks they indicate but a 
temporary recession in the Trenton epoch, during which some 
of the lower limestone was worked up. It is, however, re- 
markable that this limestone had already hardened. 
The conclusion to be drawn from the comparison of the 
four Paljeozoic terranes at Wellstown, and in the lower Mo- 
hawk valley, is that equal conditions existed at both places 
during each of the four periods. The deposits in the Mohawk 
valley are evidently those of an open, unbroken seacoast, and 
it is a recognized fact that different sediments are deposited in 
embayments and in the open sea. The exceptional case of 
the deep fjords of Norway, which partly show the fauna and 
deposits of the deeper part of the North sea off the coast of 
Norway, can hardly be adduced here. Moreover, it can hardly 
be assumed that the successive changes in character of sedi- 
ment, taking place from the Potsdam through the Calciferous 
and Trenton to the Utica formations, should have been ex- 
actly repeated in a bay which, being formed by the drowning 
of a valley, could not have been very wide, and, lastly, it must 
be expected that the upper course of the Sacandaga river, 
which emptied in that bay, would have filled it with deposits 
of crystalline origin. 
The writer's view, that the Utica shale at Wellstown is only 
a remnant of a once continuous covering of the southern 
Adirondacks, seems also to be supported by the great number 
of fragments of Utica shale and the great quantities of dark 
clay with included shale in the glacial drift on the southern 
slope of the Adirondacks. The amount of this drift would 
seem to indicate the scouring away and working up of more 
shale than the valley deposits could have furnished, and it 
can hardly be assumed that the fissile, easily ground shale 
could have been brought from the northeast and carried over 
the x-\rchcean area. 
All these conclusions refer only to the outlier at Wells- 
town and to the southern slope of the Adirondacks, those in 
the east of this plateau not being known to me. 
The writer embraces this occasion to correct an oversight, 
committed in the first paper on current action, by not men- 
tioning the interesting conclusions of G. F. Matthew on the 
