Alcadia macilenta is a species of an operculate land snail, terrestrial gastropod mollusk in the family Helicinidae.

[1] (Original description) The shell is rather small and thin, subdiscoidal, and flattened beneath, with a pale brown coloration.

The epidermis is extremely thin, microscopically hirsute, or chagrined.

The aperture is large, and the outer lip is thin, sharp, moderately expanded, and reflected, featuring a deep curved incision below the columella, similar to that of Alcadia brownii palliata (C. B. Adams, 1849).

The elongated columella is strongly margined on the inner side.