The operculum is oval, corneous and dark brown in color. The shells are thin and corneous and rather transparent. Palpi porrect (extending forward), frons with rounded corneous projection. The operculum is very thin, corneous, with few whorls. Corneous opercula are made out of the protein conchiolin. The shell is pale corneous in color, sometimes fulvous. The shells are thin and corneous, and rather transparent. The apex is generally eroded, corneous (orange colored). They have a brown, entirely corneous, circular, multispiral operculum which fits the aperture snugly. The mineral is rather sectile, and consequently was earlier known as corneous lead, (German "Hornblei"). The periphery is broadly rounded, corneous with a few varicoid white stripes. The corneous, claw-like operculum partially covers the shell aperture. The operculum is circular, thin, corneous, orange-brown, and composed of about 10 whorls. The corneous operculum is usually well-formed and shows only a few spirals.