Spiral 
Spire 
Striae 
Striate 
Subcentral 
Suprapedal 
groove 
Suture 
Translucent 
Transverse 
Tentacle 
Truncate 
Tooth 
Umbilicate 
Umbilicus 
Viarix 
Vector 
Whorl 
= (Af < 
Winding, coiling, or circling around a central axis; the 
form of the shell of most snails. 
All of the whorls above the aperture (Fig. 4). 
Impressed lines; usually designating those impressed 
lines running in the same direction as the whorls(Fig. 
4; 6a). 
Bearing impressed spiral lines (Fig. 4; 6a). 
Nearly central; slightly off the center. 
A groove above, and running parallel to, the pedal groove 
in certain snails (Fig. 7). 
The line where one whorl of the shell is in contact with 
another, (Fig. 4;.8j, k, oUt 
Partly transparent. 
Parallel to the columella or axis of the shell; at right 
angles to the direction of the whorls; the opposite of spiral. 
An elongate sensory structure on the heads of snails (Figs. 
2, 7). In some groups it bears an eye at its tip, in others 
at its base (Fig. 3). 
Cut off (Fig. 8m). 
A short, high callus, or deposit of shelly material, in the 
aperture of some shells (Fig. 6). 
Having an umbilicus or rather wide opening at the base of 
the shell; opposite of ''imperforate"! (Fig. 8z). 
An opening in the center of the columella or axis of the 
shell (Figs. 4, 6, 8z). 
A ridge of shell material formed at the outer lip, or 
position on the shell which was once the outer lip. 
An animal that carries and transmits disease-causing 
organisms, 
One complete spiral turn of a gastropod shell (Fig. 4). 
