Shell small, thin, translucent, lemon yellow; in fresh specimens the dried animal matter shows through and gives the upper whorls a livid ashy or greenish tinge; there is also a reddish tinge on the columella ; the young shells have much the appearance of a Bela, bur doubtless develop a thickened outer lip and more pronounced notch with maturity, since several nearly mature ones show indications of it. Whorls eight or nine, turrited, angulated by the ribs on the periphery, with a small nearly smooth nucleus, and sharply sculptured subsequent surface; spiral sculpture of numerous sharp threads, quite line, and extending over the whole shell; two stronger closely adjacent threads at the hardly visible suture; transverse sculpture of strongly marked lines of growth, and about a dozen uniform, narrow, sharply elevated riblets, convex anteriorly, extending from suture to suture, and nodulated with an elongated nodule at the peripheral angle ; fasciole faintly marked, notch distinct, canal short, straight, aperture rather narrow; Lon. of shell, 6,75 of last whorl, 3.75; of aperture, 2.5; max. hit. of shell, 2.75 mm.
Habitat—Cedar Keys, on mud flats between tides. This resembles a miniature M. cerina K. & S., but is differently and much more sharply sculptured.

K. limonitella has the spire but a trifle shorter than the last whorl, the whorls rounded, and angulated behind the periphery, twelve narrow riblets, no varix; the notch shallow, deepest near the angulation ; suture hardly appressed or undulated; canal not differentiable from the aperture; ribs obsolete on the fasciole, or, if present, arched in harmony with the lines of growth. Lon. 7.1 mm; last whorl, 3.7 mm; lat. 2.5 mm.

Florida