« Shell slender and elongated, moderately curved, solid. Flesh-tinted, or opaque white and tinted posteriorly, where it is also often encrusted with a black deposit. Sculpture of about a dozen unequal narrow riblets at the apex, increasing in number but losing in prominence as the tube enlarges; growth striae scarcely noticeable, but there is often a deep jagged encircling constriction where a former fractured peristome has been repaired. Aperture circular, hardly oblique. Anal orifice small, circular or ovate, with thick walls. […] Independently of the much greater length, the ribs are finer and far more numerous and regular, (than in dentalis), and they are extremely slight or become mere striae on the anterior part or in front. The shell is also more tapering and proportionally narrower. […] D. panormum, like the very closely allied dentalis and inaequicostatum, repairs a broken peristome very clumsily, leaving a gaping record of the injury, deeper than in most species of the genus; such breaks being seen in the majority of adult specimens. »