454 Wisconsin Academy of Sciences, Arts, and Letters. 
In respect to faunal and floral distribution Lakes Mendota, 
Monona, Waubesa, Cedar, Nagawicka, and most others in south¬ 
ern Wisconsin present a similar situation. Practically all of 
these lakes have a low degree of transparency and hence have 
a shallow zone of photosynthesis. All of them have similar 
types of shore, rough in places, sandy in others, and tending to 
swamp in less exposed situations. The northern Wisconsin 
lakes are more transparent and show a correspondingly greater 
zone of photosynthesis. They are more like the Alpine lakes 
in this respect. 
In its particulate aspects, comparison with other lakes can be 
only relative. For the littoral areas much the same type of 
fauna and flora will be found in all lakes, except the very large 
and stormy lakes. Wesenberg-Lund (1908) finds similar types 
for the rock shore communities of Danish lakes, although Lake 
Mendota seems more populous. For el, Zacharias, Zschokke 
and others have worked on the fauna of alpine lakes and find a 
similarly typical fauna as far as the littoral area is concerned. 
In the aphytal area the situation differs somewhat. From a 
physiographical standpoint some of the alpine lakes are valleys 
between mountains which are filled with water. Some of them 
have a depth of more than 500 meters, and we find conditions 
at these depths which are somewhat akin to those of the ocean 
abyss. In the upper portions of the aphytal area (inappro¬ 
priately termed ‘‘abyssal area”) the fauna resembles that of 
the aphytal area of Lake Mendota. Below 50 meters this 
resemblance ceases. Practically all of these deep lakes har¬ 
bor a series of glacial relicts, and certain species of worms, in 
general, forms that never come to the shallower depths aboye 
50 meters. And as a result there is a fauna, rich in its variety 
and adaptations, which has been called an abyssal fauna (inap¬ 
propriately so, as just mentioned, since the term is preoccupied 
in a special sense in oceanology.) 
As far as the plains lakes are concerned, these “abyssal” 
conditions do not exist in them aside from the general conditions 
of the aphytal area. Their fauna consists largely of species 
which come to the surface or at least to the shallower waters at 
some time during their life. No special fauna has been de¬ 
veloped which is particulate in its predilections for great depths. 
In general, the fauna is such as may be found within relatively 
shallow waters, a fauna which connects distinctly with that of 
the shores and shallow bodies of water. 
