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THE NATURAL HISTORY SURVEY. 355 
tooth with a quadrangular base of attachment, rounded above 
and below, reflected portion small, nine-dentate, the central 
cusp the largest; intermediate tooth longer than wide, some- 
what sole-shaped, nine-dentate, cusp wider than high; lateral 
teeth longer than wide, the second nine-dentate and the third 
seven-dentate. The writer counted 55 rows of perfect teeth in 
one membrane (Fig. 134). 
Distribution: Eastern United States from Michigan to 
New York and Florida, and from South Carolina to Arkansas. 
Geological distribution: Pleistocene; Loess. 
Habitat: Found in lakes and rivers, where there is a 
muddy bottom, more frequently where there is a quantity of 
grass, in water from a foot to two or three feet in depth. 
Remarks: This.is a very common and beautiful species. 
It is unlike any other mollusk found in this region, the four 
spiral bands easily distinguishing it. In some localities it is 
rad My, \ yn 
L 
Fie. 134. 
Radula of VIVIPARA CONTECTOIDES, W.G. Binney. (Original.) C, 
central tooth; 1, intermediate tooth; 2, 3, lateral teeth. 
the predominating form, and thousands of dead shells may be 
found upon the shores of such localities as Wolf and Calumet 
lakes. It is most interesting in an aquarium, and readily 
moves about, its long tentacles and rounded rostrum extended 
to their full length, the latter bent downward, the former feel- 
ing about nervously and the shell swinging from side to side. 
The young have a foot almost black in color, with large, irreg- 
ular white spots on the under side; they are very active. The 
shell is very variable in regard to the presence of the bands, 
some specimens being perfectly plain and others but faintly 
banded. It seems to be pretty widely distributed, but is most 
common inthe southern region, in the chain of lakes. 
