59 
Three all-Bottom-land Lakes and one Sand-beach Lake between 
Liverpool and Havana 
(Mile 199.0—207.0 below Lake Michigan) 
The season’s collections in Liverpool, Dogfish, and Thompson lakes 
in 1920 were taken in early September in almost uniformly muddy bot- 
tom between near shore and the six-foot line. All of the stations visited 
in these lakes at that time were in open water, though a large part of the 
same area in all of the lakes and most of it in some of them was well 
supplied with coarse vegetation between 1913 and 1915. Mud, spongy 
with gas, was taken at two of the stations in Liverpool Lake and there 
was more or less foulness of odor and abundant bubbling at all stations in 
all three lakes. While odors were particularly bad in the Liverpool Lake 
samples, they were not nearly so bad either in Thompson or Dogfish. 
In the last-named lake there was a light covering of lighter colored silt 
over older gassy black mud, the topmost layer having its origin less than 
six months before in the dredging operations for an agricultural drainage 
district immediately north. 
In Quiver Lake the samples from muddy bottom in open water 
(mostly in the old vegetation zone, as in the other three lakes) all had bad 
odor and gave off abundant bubbles. Samples from the mud and mud 
and shell bottom in the deeper “channel” through this lake, and from the 
mud and sand near the east beach were decidedly less gassy and more 
wholesome in odor. 
While not less than six families of snails, represented by about a 
dozen species, were common or abundant in 19131915 in each of these 
four lakes, no snails at all were taken in Liverpool or Dogfish lakes in 
September, 1920, and in Thompson Lake only a small number of a single 
species. In Quiver Lake, as in Dogfish and Liverpool lakes, no snails 
at all were found in the shallower, more stagnant open portion less than 
six feet in depth; but in the “channel” fed by Quiver Creek, and toward 
shore on the east side, good numbers of Pleurocera, and small numbers of 
Musculium transversum and Vivipara subpurpurea were taken. 
The table following shows the detailed changes in the composition of 
the snail fauna in Thompson Lake only. It represents very well, also, 
with only slight alterations, the changes that have taken place in Dogfish 
and Liverpool lakes, and in the muddy portion of Quiver, the principal 
requirement being to transfer the little surviving sphaeriid at the head 
of the table to the list of species underneath that have dropped out since 
1913-1915. 
