Shell stout, rather solid, opaque white, short, the posterior fourth bevelled off toward the bluntly rounded summit ; transverse sculpture consisting of occasional faint lines of growth, nowhere very prominent ; spiral sculpture consisting of very numerous fine grooves, so crowded near the ends of the shell as to be but little narrower than the interspaces ; these grooves are only visible under a lens, are occasionally reticulated by the lines of growth and gradually become more distant toward the middle of the shell ; just in advance of the shoulder of the bevel are a small number of equally fine raised lines, which are so minute that only by the most careful inspection and under strong magnification can they be distinguished from the grooves which cover the rest of the shell ; the folds of the outer whorl are appressed toward the apex, with a somewhat thickened and irregular margin, which leaves a minute pit at the summit and about two volutions visible ; this appressed margin is often eroded, and then some four or five turns can be made out ; in advance of the bevel the shell is nearly cylindrical, rather suddenly rounded in front ; outer lip straight, slightly produced in the middle, but not bent inward toward the body, passing imperceptibly into the column, over which, as well as over the body, is a thin layer of callus ; aperture rounded and rather wide in front, narrowing to an acute point behind, shorter than the shell ; pillar with no twist or fold, continuous with the margin. Lon. of shell, 7.5 ; of aperture, 6.0. Max. lat. of shell, 4.25 ; of aperture, 2.5 mm.

In Studying the specimens labelled Cylichna dalli I found some confusion in the identification, and that two similar but distinct forms bad been placed under that name: Cylichna dalli Verrill and Cylichna vortex Dall.
The differences in the two species are clear. C. dalli is most readily distinguished by its "strongly excavated and sinuous" columella, which forms anteriorly a distinct fold or tooth-like projection where it joins the strongly curved outer lip ; while C. vortex has a gently curved columella, passing "imperceptibly" into the outer lip without "twist or fold." In this species the apical whorl is smooth, upturned, and sunken in a shallow pit formed by the two succeeding whorls, one rising a little above the other, with a slightly rounded sutural margin. In some specimens these are so closely coiled as nearly to conceal the nucleus, while in others each turn is visible. The following turns are more loosely coiled, and the outer lip joins the body whorl a little below the apex of the shell. Some of the specimens are considerably larger than Mr. Dall's types, and more slender in proportion to their length.
One perfect specimen is mm. long and 8 mm. broad ; another worn and broken one is about 29 mm. long and 13 mm. broad; while still another is 23 mm. long and 11 mm. broad. A careful study of the radula and gizzard shows that the correct position of the species is with the Cylichnae.

United States of America. Florida.