THE NATURAL HISTORY SURVEY. 219 
at the anterior part of the mantle and extending downward 
and forward to a point behind the tentacles; sometimes the 
central stripe, which extends from the mouth over the head 
to the mantle, is quite large and composed of small black 
blotches. Length of foot 13.00, width 6.00 mill. Heart situ- 
ated midway between the anterior and posterior borders of 
the aperture, to the left of the columella, pulsations regular, 
sixty-nine per minute. . 
Faw. With the usual quadrate, superior appendage com- 
mon to the genus; cutting portion arched, with a median pro- 
jection to cutting edge; anterior surface with from three to 
seven ribs which denticulate both margins (Fig. 55, J). 
Radula formula: *2+1941+19482 (42—1—42); central 
tooth with a subquadrate base of attachment, the lower outer 
Fig. 55. 
Radula of SUCCINEA OVALIS Say. (Original.) c, central tooth; 1, first 
lateral; 17, 35 marginal teeth; J, jaw. 
corners expanded and the base concave; reflection tricuspid, 
the central cusp long and wide, nearly or quite reaching the 
lower margin of the base of attachment, the side cusps very 
short; lateral teeth similar to central, longer than wide, bicus- 
pid, the inner cusp very long and wide, reaching below the 
lower margin of the base of attachment, the outer cusp very 
small; the third outer cusp on the first few laterals is rudimen- 
tary; marginal teeth modified laterals, wider than long, tricuspid, 
the inner cusp long and wide, acute, and the» two outer cusps 
short, narrow and pointed. All of the cusps are provided with 
well marked cutting points (Fig. 55). 
Genitalia: See generic description. 
Distribution: Eastern and Central parts of Northern United 
States, west to Manitoba, south to Arkansas and Georgia; 
Canada. 
