Nquma rousi is a species of sea snail, a marine gastropod mollusk in the family Horaiclavidae.
The anterior three-fifths are marked by 10–12 prominent, broad, low, rounded, somewhat protractive axial ribs which are truncated posteriorly by the channel, their terminations forming cusps.
The base of the body whorl is moderately long, marked by the feeble continuations of the axial ribs and on the posterior half by five incised spiral lines equaling those on the spire in strength and spacing and forming a continuous series with them.
The coloration of the type consists of a creamy white ground, which is almost unmarked in the subsutural channel and on the anterior half of the base on the last turn.
The ribbed portion of the whorl between the anterior and posterior portion of the base is strongly mottled with brownish orange in the intercostal spaces, less so on the summits of the ribs, while a little posterior to the middle the base is marked by two slender spiral lines of the same color.