Original description Schepman, 1913:
Shell small, sub-biconical, with short canal and subgradate spire, thin, subpellucid, white. Whorls 6l/2, of which nearly 2 form a smooth, shining, convexly-whorled nucleus; subsequent whorls angular, excavated above, separated by a conspicuous, irregularly waved suture, with a rather strong rib just below it, with short bead-like folds, lower part of whorls with oblique ribs, 15 in number on last whorl, tubercled at their upper part below the excavation, more over the basal part of whorls is crossed by faint spirals, 2 in number on penultimate, about 10 in slightly contracted last whorl, of which latter the upper ones are more conspicuous, bead-like in crossing the ribs, those on the canal plain, lastly the whorls are crossed by growth-lines. Aperture elongately oval, angular above, with a short, wide canal below; peristome thin, broken, according to growth-lines with a wide, rather deep sinus above, then considerably protracted, columellar side concave above, slightly tortuous below, with a conspicuous, appressed layer of enamel.
Alt. 8.5 mm., lat. 3.5 mm.; apert. alt. 3.75 mm. lat. 1.75 mm.


Description Shuto:
The protoconch is large (D=0.9 mm) and paucispiral consisting of one and seven-tenths volutions, of which the first one is low dome and the second is normal and provided with a few weak, curved axials in the last part. There is no sharp end mark, but the abrupt appearance of subsutural granules and infrasutural groove indicate the beginning of the teleoconch. The weak peripheral angulation appears at the half turn of the first whorl and abruptly becomes sharp and granulated on the second. The opisthocline axials range from the lower suture to little above the angulation. They hardly reach to the basal surface on the body whorl. The spirals consist of a granulated subsutural cord and the lateral lirae and threads. The growth lines are distinct, especially on the anal band. The aperture is rhomboid with short, open canal, which is slightly notched at the end. The anal sinus is broadly curved and moderately shallow except at the last part of the body whorl, where it is deep and V-shaped with the apex slightly below the middle of the anal band. The parietal callus is moderately thick. The basal fasciole is moderately strong.

Shell small, subbiconical, with short canal and subgradate spire, thin, subpellucid, white. Whorls 6,5 , of which nearly 2 form a smooth, shining, convexly-whorled nucleus; subsequent whorls angular, excavated above, separated by a conspicuous, irregularly waved suture, with a rather strong rib just below it, with short bead-like folds, lower part of whorls with oblique ribs, 15 in number on last whorl, tubercled at their upper part below the excavation; moreover the basal part of whorls is crossed by faint spirals, 2 in number on penultimate, about 10 in slightly contracted last whorl, of which latter the upper ones are more conspicuous, bead-like in crossing the ribs, those on the canal plain, lastly the whorls are crossed by growth-lines. Aperture elongately oval, angular above, with a short, wide canal below; peristome thin, broken, according to growth-lines with a wide, rather deep sinus above, then considerably protracted, columellar side concave above, slightly tortuous below, with a conspicuous, appressed layer of enamel.

The present species agrees with Paradrillia MAKIYAMA, 1940, for the important characteristics including the protoconch and aperture. The present species, however, shows still some differences from other forms of Paradrillia. All the known species of that genus have taller spire and longer axials than the present species. The axial ribs of Paradrillia extend from suture to suture even on the adult whorls and they reach the lowest part of the basal surface. Furthermore the anal band is sculptured with fine spiral threads.