PAPERS ON ZOOLOGY 171 
of clear forest floor. It also lives in crumbly soil. It is associ- 
ated with a host of other snails, particularly the following: 
Helicodiscus parallelus, Zonitoides arboreus, Gastrocopta tap- 
paniana, G. holzineri, Strobilops labyrinthica, Pyramidula per- 
spectiva and alternata, Zonitoides nitidus, Z. minusculus, 
Vitrea indentata and hammonis, Paravitrea significans, Euco- 
nulus chersinus and Sphyradium edentulum. All, or most of 
these, are species that inhabit the moist areas under logs, or 
under bark. In Mr. Hart’s back yard, contracta was associ- 
ated with G. armifera, Vallonia pulchella, Buconulus trochi- 
formis and Strobilops affinis. The movements of contracta are 
slow and precise, the shell being carried erect, though appear- 
ing cumbersome for the animal. 
81. G. holzigeri (Sterki)—Brownfield Woods, Champaign 
Co. Found only on one occasion, under a log, associated with 
G. contracta and Helicodiscus parallelus. It prefers exposed 
hillsides. 
82. G. pentodon (Say)—Brownfield Woods, Champaign Co., 
Muncie, Vermilion Co., very rare. 
83. G. tappaniana (C. B. Adams)—Monticello, Piatt Co., 
Brownfield Woods, and University Forest, Champaign Co., Hil- — 
lery, Vermilion Co. This species is rare in the Brownfield 
Woods, occurring only in moist places, such as under logs, pieces 
of bark and dead leaves, stones, and rubbish of all sorts, or on 
twigs or at base of trees. At Hillery I found it under pieces of 
bark in the river bottoms, associated with contracta and 
Carychium exile. The shell is carried almost flat. The animal 
moves about very sluggishly. 
GENUS VERITGO Muller, 1774 
Subgenus Vertigo s. s. 
84. V. ovata Say—Monticello, Piatt Co., low moist places, 
under leaves, stones, sticks, ete. 
85. V. tridentata Wolf—Brownfield and Cottonwood 
Woods, rare. Under loose bark of fallen trees, associated with 
Gastrocopta contracta and Sphyradium edentulum. Accord- 
ing to Binney, this is one of the more aquatic species. Shimek 
records it on rather exposed, rocky, moss-covered banks. 
