176 ILLINOIS ACADEMY OF SCIENCE 
arboreus and Philimycus carolinensis. It seems to have respect 
for the slimy mucus of Philomycus, but the stiff hairs on the 
shell of Polygyra hirsuta do not seem to worry it. It is noc- 
turnal in habits. 
Superfamily Aulacopoda 
Family Zonitidz 
Subfamily Zonitidz 
GENUS VITREA Fitzinger, 1853 | 
100. V. hammonis Strom—Monticello and White Heath, 
Piatt Co., Brownfield and Cottonwood Woods, Urbana, St. 
Joseph, Champaign Co., Muncie and Hillery, Vermilion Co. 
This species prefers a moist situation. It is gregarious, occur- 
ring in great numbers in crevices of the bark of decaying trees, 
logs and in debris. It is usually associated with Huconulus 
trochiformis, Gastrocopta contracta, Zonitoides nitidus and 
Carychium exile. 
101. V. indentata (Say)—Monticello and White Heath, 
Piatt Co., Brownfield and Cottonwood, Urbana, St. Joseph and 
Homer, Champaign Co., Muncie and Hillery, Vermilion Co. 
Very abundant, gregarious, almost as abundant as Z. arboreus, 
occurring in almost as many diverse habitats. It was collected 
in the interior of very soft and wet logs, in small cavities in the 
pileus of a fleshy fungus (Russula emetica Fr.) in the inter- 
stices of bark, under logs, in crumbly soil under logs, in leaf 
mould, under loose bark of standing dead trees, in moss, under 
fallen twigs, under stones, in both high and low places, at times 
in situations that were quite dry. It was found almost always 
with Z. arboreus and nitidus, but frequently with the following 
species also: Polygyra hirsuta, thyroides, monodon, fraterna, 
and fraudulenta, Helicodiscus parallelus, Pyramidula alter- 
nata, P. perspectiva, Vitrea hammonis, Paravitrea significans, 
ELuconulus chersinus, Philomycus carolinensis, Strobilops laby- 
rinthica, Gastrocopta contracta and Agriolimaz campestris. 
In bringing to the laboratory Pupidex, Zonitide and other of 
the smaller snails, it was quite an easy matter to separate 
indentata. All that was necessary was to slightly moisten the 
entire mass and then just pick up the snails that were crawling 
away. These were indentata,—it is not a shy species, in fact is 
perhaps our boldest and most active one. It carries its shell 
