THE NATURAL HISTORY SURVEY. 15 
Will County. Numerous small streams empty into the Des- 
plaines in this vicinity and afford excellent localities for mol- 
luscan life. The river bottom land is low and swampy, but 
outside of this the ground is higher and supports a good forest 
of large trees, affording protection to many species of land 
snails. The bed of the streams and creeks is composed of a 
soft, black mud, very conducive to the growth and perfection of 
mud-loving species, such as Unio and Sphzrium. All of the 
species found here are exceptionally large and fine, owing prob- 
ably to the large quantity of limestone in the vicinity. The 
drainage is into the Illinois River via the Desplaines River. 
LiverpooL, Inp.—This interesting locality is situated 
twenty-seven miles from Chicago, near Deep River, in Lake 
County, Indiana. The drainage is into Lake Michigan through 
the Little and Grand Calumet rivers. The upper part of Deep 
River sometimes drains into the Desplaines drainage in times of 
particularly high water. The Little Calumet River runs through 
low swamps and meadowland, where there is an abundance of 
black loam and mud. To the east, near Tolleston, there are 
numerous sand hills on high ground, and to the west an abun- 
dance of tall timber on high land. The ground is covered with 
a rich mould, very conducive to the growth of Helices. Deep 
and Little Calumet rivers have a muddy bottom and the water 
is quitedeep. Unios (rectus, undulatus, luteolus, etc.) are found 
here in great abundance and of large size and fine development. 
Limneids, Physz and other fresh water shells thrive abundantly. 
Liste.—This locality is about a mile north of the town of 
Lisle and lies partly in Lisle and partly in Milton townships. It 
is twenty-three miles from Chicago. The drainage is by the 
east branch of the DuPage River into the Desplaines River. The 
soil is a black loam and the bed of the river is covered witha 
slimy, black mud. The region isnot well wooded. Fresh water 
mollusks are very abundant. 
Evanston Bic Woops.—This locality is situated three 
miles west of North Evanston and thirteen miles north of 
Chicago. This is the largest patch of woodland in the area, 
and is noted for its good collecting. The ground in the spring 
is flooded, making small lakes here and there which abound 
in mollusks, particularly the genus Spherium. The ground is 
carpeted with a heavy mould and is strewn with fallen tree 
trunks and branches. Nettles also abound and are much sought 
after by the land shells as food. About two miles east of the 
