Diagnosis: Shell biconic-claviform with greatest width more or less median, b/l 0,39-0,44, a/l 0,34-0,41, aperture relatively large, whorls weakly convex anteriorly, slightly concave posteriorly, not swollen below suture: no fasciole; anal sinus moderately shallow, opening directed outwards; axial ribs low, 8-11 on penultimate whorl, spiral lirae fine, feeble to obsolete, often restricted to base; two colour forms: (a) dark brown, with or without paler ribs, (b) base of body whorl light brown, posterior part and spire deep brown with white ribs, subsutural region blotched and flecked with brown on white; protoconch breadth 1,20-1,25 mm. Attains 12,5 mm.
Description: Shell biconic-claviform (b/l 0,39-0,44, a/l 0,34-0,41), spire initially coeloconic, later slightly cyrtoconic. apex somewhat papilliform, aperture moderately large; teleoconch whorls about 5, suture shallow, each whorl rising high up preceding one, whorls gently convex with median periphery, not shouldered, shoulder slope shallowly concave, no distinct subsutural cord; left side of base of body whorl slightly concave, fasciole not developed, false umbilicus absent or very slight. Aperture oblong, greatest width at about posterior third, siphonal canal wide, its end not notched; columella only slightly convex, parietal region concave; callus moderately thick, on columella with slightly free edge, in parietal region thinner except for a large posterior pad, which constricts entrance to anal sinus; labrum in side-view gently convex, without a stromboid notch; anal sinus moderately shallow, asymmetrically U-shaped, its opening directed outwards.
Sculptured by short, low to very low, rounded axial ribs, usually crossed by very fine spiral threads (sometimes obsolete), lip not preceded by a distinct varix. Axial ribs equal to/wider than intervals, sides gently sloping, opisthocline, evanescing rapidly on shoulder slope and on base at level of parietal pad, weak to absent on last third of body whorl; about 9 on early whorls, 8-11 on penultimate one. Spiral threads weak or obsolete, sometimes traceable only on early whorls, generally 12-18 on base of body whorl.
Two intergrading colour forms: (a) dark brown, either uniform or with paler ribs, or (b) base of body whorl moderate orange to light brown, axial ribs white, with moderate to strong brown intervals, with a zone of that colour at level of parietal nodule (demarcating upper limit of brown base); subsutural region white, blotched with moderate to strong brown; external pattern visible inside aperture.
Protoconch narrowly domed, of about 2 whorls, apex somewhat depressed, rest moderately convex, last quarter whorl apparently with feeble axial riblets and spiral striae, but limits obscure; breadth 1.20-1,25 mm, height 1,05-1,10 mm (b/h 1,09-1,19).
Dimensions (adults): 11,2x4,6 mm, 9,2x4,0 mm. Attains at least 12,5 mm (apex worn); 14x5 mm (Sowerby).

Barnard (1958) erred in synonomizing this species with Psittacodrillia diversa (Smith, 1882), which has a broader, more convex body whorl, less papilliform apex, more strongly developed and numerous spiral lirae, and distinctive orange colour.

South-Africa. False Bay to eastern Transkei, littoral. Surf-tumbled shells of this strongly patterned species are not uncommon in beach-drift, but no living examples or even truly fresh shells have been seen. The typical dark brown form is the rarer of the two colour morphs.