124 Wisconsin Academy of Sciences, Arts, and Letters. 
of Oshkosh; Coleoptera is represented by adults of Hydrovatus 
pustulatus, Haliplus ruficollis, Stenelmis hicarinatus, and Bidessus 
flavicollis. Acarina includes Limnesiopsis, Fiona, Limnesia, and 
Arrhenurus, all rare and occurring mostly at station 36, the small 
pool behind the beach at Roe Point. Leptocerids among Trichoptera 
are uncommon; and a single larva of the Lepidopterid Nymphula 
was found at station 23, the marsh behind Asylum Point. Leeches 
occur at five stations and include Glossiphonia stagnalis, G. neph- 
eloides, G. fusca, Erpohdella punctata, and Dina parva. 
The Vegetation Areas. Plants, owing to the shallowness of the 
water, are very abundant in Lake Winnebago, and occur com¬ 
monly to a depth of two meters. Beyond this depth they decrease 
very rapidly. No plants (excepting algae and microscopic forms) 
were found below 2.5 meters and no filamentous algae below 3 
meters. The great plant areas are in shallow water, 0.3 to 1.5 
meters in depth, in bays and along the margins of shores. Plant 
zones of greater or less size extend entirely around the lake, bor¬ 
dering the shore. All of the bays contain an extensive flora which 
supports a large and varied fauna. Many individuals collected 
from the bottom are migrants, either by intention or accident, from 
these plant areas. All kinds of bottom, except boulder, support an 
extensive flora, and some plants occur on this inhospitable sub¬ 
stratum, as at habitat 43 where two species of Potamogeton and a 
Vallisneria occurred. 
Plants serve three very useful purposes for the bottom fauna. 
First, they form a binding medium which prevents the bottom 
from shifting; second, they form a means of attachment and sup¬ 
port for the crawling and clinging members of the fauna; and 
third, they provide a foraging ground, either directly by their own 
material, or indirectly by harboring many small animals used as 
food by other members of the fauna or by providing support for 
filamentous algae, the principal food supply of many forms of 
animal life. The statement so often made by biologists—that an 
abundant fauna is dependent upon an abundant flora—is strik¬ 
ingly emphasized in Lake Winnebago, for the animal population is 
very large per unit area and the flora is equally luxuriant. The 
lake’s large and varied fauna is due to the shallow depth which 
enables a rich flora to become established. 
