The tooth arrangement referred to appears in the description of Cerion (Paracerion) tridentatum PiIsbry and Vanatta, which is quoted in its entirety below:
"Shell similar externally to C. incanum, but aperture long, ovate, much higher than wide; cone of spire longer, several whorls following the nepionic ones densely striate. Parietal lamina small, short, central, with a smaller accessory denticle to the left of and beyond its inner end, and another lamina slightly to the right and deeper within. Alt. 25-27½; diam. 9-10 mm.