in the Connecticut river Sandstone. 101 
rows, the parallel sides of which are more ng pte than the 
transverse edges which subdivide the furrows into cells. 
It may here be observed that the fan- tote rt is s scarcely 
at all visible in the first described variety. The diameters of 
the cavities in both are the same, being foie one to ak = a 
half inches. The differences in ‘the depth of the cavities in the 
two varieties probably grew out of the hardness of the bottom 
where they originated. 
The second kind, or shallow meal ah are constantly asso- 
ciated with the third variety presently to escribed, being 
situated from one-quarter to one-third of an teh only above 
them. A series of singularly interrupted and overlapping wave 
lines, obviously the remains of the parallel or zigzag, furrow- 
edges of the second variety above described, plainly enough 
show that ‘isap were produced by ripple action, ‘dooegh a gentle 
current of water setting transversely across the furrow-ridges. 
The third kind of impressions is considerably different from 
either of the foregoing, and requires a more particular descrip- 
tion. e hexagons are disposed in long, nearly straight, par- 
ae series, though now and then a row suddenly runs _s where 
t abuts directly against a a ae or in other words a 
ee is seen to bifurcate, or to be replaced by a furrow. The 
cavities in this variety have nearly Neable the breadth or area 
of the two first varieties. In hexagons of the third variety the 
two si tage sides that are at right angles to the furrows have 
treble the length of the other two pairs, which seemingly have 
n shortened at their expense. The angles of the hexagon 
sae are not equal. The four situated at the extremities of the 
longer sides, are less than 110°, while the two remaining (trans- 
versely opposite) ones are over 130°. The four shorter edges 
moreover are often flattened down into a broad band, while the 
long transverse ridges remain thin and sharp, though not straight 
at top, _ doers arcuated. Indeed they are sometimes so low 
and faint as to become almost obsolete, thus changing the row of 
cells uae into a trough, whose borders are composed of the 
shorter zigzag sides of contiguous hexagons (under angles of 
130°) ;—the whole seeming to have originated in a contraction 
of these sides, and a corresponding elongation of those at right 
angles to the furrow. The flattened band is not perfectly hori- 
zontal, but inclines a little toward the bottom of the trough, and 
eetentige’ in one gerne throughout the series,—its lower se 
being situated upon the upper or most shallow side of the he 
onal cell or cavity, or in other words the greatest depression in 
the furrow adjoins the superior edge of the band—it bom 
