Megalonyx in Holmes county, Ohio. — Clay pole. 151 
This graduates downwards into a silt or quicksand without shells, 
very clammy and of great depth, resembling what is usually de- 
posited from glacial waters. I was informed by Mr. Drusllell 
that some years ago a boring was carried down into this silt to the 
depth of one hundred and forty feet without reaching the rock. 
Judging from the topograph} 7 this is not unlikely. The surface of 
the drift is here nearly two hundred feet above Millersburg, and 
its depth is evidently very great. The swamp is on the site of a 
deep hollow between two lines of morainic mountains on its north 
and south sides. The outlet is at the east end and is narrow. It 
has also been cut down a few feet artificially and had previously 
been somewhat lowered by the outflowing stream. The swamp is 
very irregular in shape but may measure a mile in length from 
east to west and half as much in breadth from north to south. In 
one place a long point projects from its northern bank nearty cut- 
ting it into two parts, and opposite this is a small island of the 
same gravelly material still further separating it. At this point 
formerly existed a large beaver-dam from which hundreds of 
gnawed sticks were taken in the digging of the ditch*. This must 
have aided in holding back the water at least in the western part 
of the swamp. The outlet leads into a small stream called 
Doudy's run, and then into the Killbuck and Muskingum. 
VII. The History. 
The sequence of events in the history must have been nearly as 
follows. The southern line of moraine was formed when the ice- 
front stood at the south side of the swamp and was nearly at its 
greatest extension. It consists for the most part of material 
rolled and washed along under the ice, that is of rounded gravel 
and clay. A time of recession followed during which little mo- 
rainic matter was deposited, and the hollow in which the swamp 
now lies was produced. Another period of rest or of slight ad- 
vance ensued, and the northern moraine was dropped, meeting the 
older one at both ends and enclosing between them a rudely 
crescentic basin. This basin was kept full of water by the incit- 
ing ice, and its overflow escaped by the lowest point in the rim, 
*Some of the tooth-marks which] saw on these sticks are so large 
that they strongly suggest the greal extincl beaver of Ohio (Castoroides 
oMoensis) as the. architect of the dam rather than tin' much smaller 
living beaver (C. canadensis). 
