Phorcus mutabilis

Its color is usually grayish-yellow, yellow or flesh-tinted, more or less obviously marked with obliquely radiating lines or maculations of dull crimson, sometimes broken into tessellations, sometimes faintly, minutely articulated with reddish, appearing nearly unicolored.

The 5 to 6 whorls are slightly convex and spirally finely grooved.

It is scarcely edged with pearl, the tooth or lobe less heavy, more acute than that species.

The umbilical region is always more excavated than Phorcus articulatus.

The umbilicus is open, or nearly closed by the callus at the insertion of the columella.