Two New Species of Fossil Footmarks. 57 
distance, against which the east end of Holyoke abuts, with only 
anatrow space between. It is obvious then, that this locality 
must have been the north shore of an estuary, opening southerly, 
and extending to what is now Long Island Sound. ‘That it was 
salt-water is evident from the occurrence of fucoids in the same 
basin, a few miles south. Now we know that the current through 
this estuary was either north or south, for the ripple marks have 
an east and west direction, and in size they correspond with 
those made by the waters of the Connecticut on the sand in the 
same region. ‘The direction of that stream also is south ; and 
some have thought that the floods of that stream may have 
brought in the sand which filled the tracks. But the locality 
m 
the animals trod. Indeed, it would be exposed to no current 
that I can conceive of, sufficiently powerful to move such coarse 
and the tides :—not the daily tides, but the spring tides. Sup- 
pose the animals walked along the shore during neap tide, an 
that no rain fell till the return of spring tide. By that time the 
mud might have become so indurated, that even such coarse ma- 
terials might have been brought in by moderate waves, without 
. 
erasing the impressions. It might be also that the river, which 
new chapters will yet be brought to light, when its stony leaves 
shall be still farther opened. 
Srcoxp Senizs, Vol. 1V, No. 10.—July, 1847- 8 
