ON THE DEEP-WATER FAUNA OF LAKE MICHIGAN, 
BY DR. WILLIAM STIMPSON. 
A knowledge of the character of the animals and plants 
living at the bottom of the great North American Lakes, 
the largest bodies of fresh-water in the world, has long been 
a desideratum ; and dredging operations have this year been 
initiated by the Chicago Academy of Sciences which have al- 
ready produced interesting results. The first dredgings were 
made off Chicago, where the waters were found to be shal- 
low, and the bottom sandy or gravelly. At a distance of 
eighteen miles from land the depth was but fourteen fathoms. 
The bottom was nearly barren of life. We obtained, how- 
ever, specimens of the larva of some neuropterous insect, a 
Clepsine, a flesh-colored leech belonging to a new genus; a 
Lymnea, two Melanians and a Plumatella. The plants 
consisted of a moss, a Chara, a Nostoc,and one other alga. 
The next investigations were made in the more central 
and deeper parts of the lake. Dr. Hoy of Racine had been 
for some time endeavoring to ascertain the nature of the food 
of the whitefish, which had previously remained entirely un- 
known, These fish being caught in gill-nets and “pounds,” 
are generally taken from the water some hours after being 
actually entrapped, and the food in the stomach becomes 
thoroughly digested, and its character undistinguishable be- 
fore it can be obtained and examined. Dr. Hoy, however, 
after long search, succeeded in obtaining some fish in which 
the eontents of the stomach was in a comparatively fresh 
state, and ascertained it to consist mainly of remains of 
small crustaceans. These he submitted to me for examina- 
tion, and among them I had the pleasure of detecting indi- 
cations of the existence of marine forms in the lake. 
It thus became highly desirable to examine the ground 
upon whieh Dr. Hoy's fishes had been obtained, and accord- 
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