THE NATURAL HISTORY SURVEY. aek 
While moving about, the rostrum is kept constantly in motion, 
as well as the long, filiform tentacles, and the lingual apparatus 
may be distinctly seen, as in Linea, the mouth being a long, 
vertical slit in the end of the rostrum. The animal frequently 
comes to the top of the water and, pushing its rostrum above 
the surface, will remain in this way for hours. 
Livescens has been found in a fossil. state on Balmoral 
avenue, north of Bowmanville, on the corner of Sheffield and 
Lincoln avenues, and in sand banks on the lake shore, north 
of Graceland avenue. ~ 
132a. Goniobasis livescens depygis Say, pl. xxxv, fig. 8. 
Melania depygis Savy, New Harm. Dissem., p. 291. 
Melania occulta ANTHONY, Proc. Phil. Acad., p. 5, 1860. 
Shell: Differing from typical “vescens in being narrower, 
the two color bands brighter and more conspicuous and the 
columella not tinged with purple. 
Length. Width. Aperture Length. Width. 
23.00 8.50 9.00 4.50 mill. (coll. Ferriss.) 
17.25 7.75 8.00 4.50 “ (coll. Ferriss.) 
Animal, Jaw and Dentition: As in livescens. 
Genitalia: Not observed. 
Distribution: Same as livescens. 
Geological distribution: Pleistocene; Loess. 
Habitat: Same as ivescens. 
Remarks: After the examination of several thousand 
specimens from Northern Illinois, and after consulting with 
several conchologists, it seems imperative that depygis must 
become a variety of /vescens, and it is an open question if it 
is entitled to even varietal rank. The writer has before hima 
set of Goniobasis in which there is a perfect gradation from the 
heavy, swollen /vescens, with dark shell and purple tinged col- 
umella, to the most graceful depygis, with light shell and dark 
spiral bands, and white columella. The variety has been found 
only at Hickory Creek. 
FAMILY AMNICOLID&. 
“Tentacles elongated, with eyes at their outer bases. Oper- 
culum subspiral or concentric. Shell small, globular or elon- 
gated, spiral. Aperture broadly oval, lip continuous. Gener- 
ally umbilicated.’’* 
*Tryon, continuation of Haldeman’s monograph, No. 1, p. 8. 
