3 “= i 
Natural Terraces and Ridges on Lake Erie. 35 
found, represented as being water-worn like’ drift-wood. Those 
in my possession are solid, with a very fine grain resembling the 
willow, +3 
-_ Dr. Moore, an intelligent physician of my acquaintance, says 
he has séen shells thrown from the bottom of wells, resembling 
‘periwinkles,” a common name for Lymnea. Similar shells in 
fragments are said to have been thrown from a pit two miles west 
of Cleveland, on the north ridge. In the ‘blue marly clay” be- 
neath this ridge, I have found a Helicina, and a Planorbis, shells 
characteristic of the loess of the Rhine, and of St. Louis, and 
the Wabash in Indiana. The paleontological evidence is there- 
fore, as far as it goes, in favor of the idea of very recent and fresh 
water deposits. 
; twenty feet; and consequently the base has an equal rise in a 
longitudinal direction. ‘I'wo miles west of Ridgeville Centre, 
the top of the middle ridge has descended from 168 to 149 feet. 
The foot of the north, or first ridge, and of the terrace on which 
il is frequently situated, approaches nearer to a horizontal line 
than the ridge itself, but still differs from a perfect level. It is at 
Conneaut Creek, : : : : ; . 75 feet. 
Four miles east of Ashtabula, ee ae 
6c 
SP ae ene” 
Several miles west of . . , Fie oe 
| Painesville, ; ‘ . . . : ee Ee 
, East of Willoughby. several miles, - 60t065 © 
2 " : 1 ce 
. Three miles west of Willoughby, . . . 60 
P Euclid Creek, 12 miles east of Cleveland, . 75to85 “ 
: Seven miles east of igre: ‘ Sipe ius 
dt v4 tc cs . . Fa 102 ” 
hes > A ae a tdi tad <- den 
Rockport, . * ° . . * 2 z 70 
Avon, ‘ f s fe - iy . e 70 - “cc 
It is not easy to determine with precision where the base or 
foot of a ridge graduates into the plain; and consequently there 
'$ not that accuracy in the elevations for the base, just given, that 
Wwe attain when measuring the summit or crest. But they are a 
-. close approximation, and although remarkably uniform, are b; 
» _- NO Means equal, as they should be if the base of the ridge i] 
___ Sented an ancient coast-line; the greatest difference being forty: 
ae feet, or about the same as the variation along the top of the 
second ridge. 
