THE NATURAL HISTORY SURVEY. 161 



Radula formula: f+V 5 -H+y+i + V+i (28- I -28); cen- 

 tral tooth with a base of attachment a little longer than wide, 

 the lower outer corners expanded; reflection long and wide, 

 reaching almost to the lower edge of the base of attachment, 

 with a large and well-developed central cusp and subobsolete 

 side cusps; lateral teeth similar to central tooth, the outer lower 

 angle of the base of attachment expanded, the side cusps rep- 

 resented by bulgings; marginal teeth variable, at first with a 

 long and narrow spear-shaped inner cusp and a small outer 

 cusp; the inner cusp soon becomes bifid (16-18), and finally 

 the tooth becomes wider than long and with four sharp cusps; 

 all of the teeth have well-developed cutting points (Fig. 24); 

 there are about 120 rows of teeth. Binney gives 40-1-40 

 and Morse 39-1-39 teeth. The membranes examined were per- 

 fect. 



Genitalia: "The penis sac is long and slender, with the vas 

 deferens and retractor muscle entering its apex and its orifice 

 entering the vagina near its base. The genital bladder is long, 

 stout, cylindrical, with a median contraction; its duct is hardly 

 distinct from it, with an entrance opposite that of the penis sac. 

 The prostate is very large." (W. G. Binney.) 



Distribution: Western Pennsylvania to Virginia, Illinois 

 and Tennessee. 



Geological distribution: Pleistocene; Loess. 



Habitat: Same as that of clausa. 



Remarks: This species is at once distinguished irom clausa, 

 the only species with which it is likely to be confounded, by its 

 imperforate umbilicus, its triangular aperture, and its elevated, 

 subconical spire. In confinement the animal is rather slow 

 and careful in its movements. The shell is carried well balanced, 

 a trifle back of the center of the animal, and lies almost flat. 

 A variety occurs with a dark shell and purple lip. The species 

 does not seem to be very common, and those found by the 

 writer have been solitary in habit. It is confined to the southern 

 and western regions. 



60. Polygyra multilineata Say, pi. xxx, fig. 2. 



Helix multilineatus SAY, Journ. Phil. Acad., Vol. II, p. 150, 1821. 



Shell: Globosely depressed, rather fragile, imperforate; 

 surface sculpture as in profunda; nuclear whorls smooth; color 

 yellowish-horn or russet, with from fourteen to twenty reddish- 

 brown bands of variable width; periphery rounded; sutures 



