PAPERS ON ZOOLOGY 165 
GENUS POMATIOPSIS Tryon, 1862 
49. P. lapidaria Say—Crystal Lake, Champaign Co. Am- 
phibious ; among vegetation and debris at margins of ponds. It 
withstands much dessication and is very often to be found in 
temporary waters. 
Family Pueuroceride 
GENUS PLEUROCERA Rafinesque, 1818 
50. P. elevatum Say var. Lewisii Lea—White Heath and 
Monticello, Piatt Co. It prefers sandy bottoms of large 
streams, or among rocks. At Havana, Illinois, this is a very 
common species. The Piatt Co. specimens are very typical, and 
the species is fairly abundant, associated with Goniobasis 
livescens. 
GENUS GONIOBASIS Lea, 1862 
51. G. livescens Menke—Monticello, Piatt Co., and Hillery, 
Vermilion Co., among water weeds, on muddy or sandy bot- 
toms; common. 
52. G. pulchella Anthony—“‘Big Vermilion River” accord- 
ing to Mr. W. W. Calkins, Mr. E. C. Faust in the Journal of 
Parasitology (Vol. iv, No. 3) gives as the host of Cercaria 
aurita Faust, G. pulchella, but he does not state who determined 
his material. He gives as his locality “Salt Fork of Sangamon 
River, Homer,” which locality is somewhat dubius,—geograph- 
ically speaking. 
53. G. semicarinata Say—“Big Vermilion River” according 
to Mr. Wm. A. Marsh. This may prove to be a mistake for 
G. costifera Haldeman, which species it resembles considerably. 
Subclass Euthyneura 
Order Pulmonata 
Suborder Basommatophora 
Superfamily Limnophila 
Family Physide 
GENUS PHYSA Draparnaud, 1801 
54. P. ancillaria Say var. warreniana Lea—Crystal Lake, 
Champaign Co., after the Salt Fork was dredged. Not com- 
mon. It resembles P. sayii but is only one-half its size. The 
specimens are mature. 
