The
shape of the shell is oblique-heliciform. The color of the shell is white and translucent. The shell has six
whorls. The
spire is weakly convex. Apical angle varies from 21.3 to 24.8.
Suture is distinct. Shell is glossy with transverse ridges on upper surface.
Embryonic shell is large, with about 2½ whorls. Subsequent whorls are regularly coiled.
Body whorl is axially deflected. The
aperture is rectangular with rounded angles.
Peristome is discontinuous. The
parietal callus is relatively thick.
Lip is thickened, broadly expanded and reflected. There is shallow sinulus present. Apertural dentition is with very large, strong parietal lamella, one palatal lamella, one large basal lamella, one strong columellar lamella and one small supracolumellar lamella.
Umbilicus is widely open and shallow. The width of the shell is 5.6–5.8 mm. The height of the shell is 3.2–3.3 mm. No live specimens have been found as of its type description in 2017.
Similar species Perrottetia hongthinhae differs from
Perrottetia dugasti in having a single parietal lamella, a strong higher basal lamella, and a rectangular aperture with rounded angles. Compared to
Perrottetia messageri, the
Perrottetia hongthinhae has a smaller shell with weak transverse ridges, and the body whorl moderately expanded. Compared to its congeners from Vietnam (
Perrottetia aberrata,
Perrottetia daedalus,
Perrottetia gudei,
Perrottetia mabillei, and
Perrottetia simonianus),
Perrottetia hongthinhae has a relatively smaller shell, and the profiles of the shell base are quite different in all five species. The
Perrottetia hongthinhae differs from
Perrottetia unidentata in its smooth shell surface, smaller size, and in having a rectangular aperture with rounded angles. ==Ecology==