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PAPERS ON ZOOLOGY 157 
Vitrea indentata, V. hammonis, Paravitrea significans, Hucon- 
ulus chersinus, Agriolimax campestris, Philomycus carolinen- 
sis, Pyramidula alternata, P. solitaria, P. perspectiva, Helico- 
discus parallelus, Sphyradium edentulum, Succinea avara, 
Strobilops labyrinthica, Gastrocopta contracta, G. tappaniana, 
G. holzineri, Vertigo tridentata and Carychium exile, a total of 
twenty-seven species. 
The Salt Fork drainage feeds into the Vermilion. The“ Bone- 
yard” branch is its source. A few intermittant feeders are 
found as far north as Rantoul, near the Mackinaw region where 
also the Sangamon has its source. The first Unios to be found 
are Carunculina parva and Anodontoides ferussacianus sub- 
cylindraceus, and wherever ox-bows are formed, Anodonta 
grandis is almost certain to be found. But few Spheriide 
were found, no doubt more exist if only a more careful search 
is made for them. In the ecologically annotated list of species 
data is given covering the habitats of the Ancylide, etc., found 
here. At Crystal Lake the littoral fauna is well developed,— 
mostly insect and snail, of the latter Lymnxa humilis modi- 
cella, L. parva, Pomatiopsis lapidaria and Physa gyrina being 
the dominant forms. 
In 1910 the Salt Fork was dredged and as a result many 
faunal changes occurred. Numerous ox-bows were formed and 
at times these were literally alive with Carunculina parva, 
Musculium transversum and several species of Spherium, and 
of course, large numbers of dragon fly larvae and nymphs. On 
one occasion a nymph of Gomphus sp. was collected with one of 
its legs caught between the valves of Spherium striatinum. The 
dredged area is practically devoid of mollusks, though in time 
these will invade it. During the Winter, Physa gyrina and 
Planorbis trivolvis were frequently found crawling on the 
underside of ice. 
At St. Joseph, prior to dredging, the stream was rather wide 
and had very muddy banks. Amblema undulata and Caruncu- 
lina glans were the most numerous clams. The latter was 
only found here and particularly near the outlet of a slaughter 
house. C. parva was not found at this particular place, though 
elsewhere it was common. Many of the “Quadrulas” were 
found with their shells deformed by the hoofs of cattle. 
