Diagnosis: Shell as in M. ustulata but cylindric-biconic, left side of base more concave, axial ribs fine, subequal to spiral lirae, more oblique and arcuate than in ustulata, 28-39 per whorl, spiral lirae 12-14 on penultimate whorl, 17-20 on base; off-white, either with two spiral lines (one on spire) of orange-brown dots, or two broad zones of orange-brown flames; protoconch breadth 0,63-0,70 mm, 1st whorl depressed; maximum length 5,2 mm.
Description: Shell cylindric-biconic (b/1 0,40-0,45), spire high, blunt, somewhat cyrtoconic, apex not papilliform; a/10,43-0,48; teleoconch whorls about 3J, moderately convex, with periphery at basal third and a very narrow shoulder bordering the relatively deep suture, body whorl strongly convex, left side of base shallowly concave. Aperture long, narrowly lanceolate, acute posteriorly, greatest width median; labial callus fairly thin, without even vestigial pleats, edge of labrum distinctly incurved, smooth inside, thin, preceded externally by a varicoid thickening; labrum moderately strongly convex in side-view, anal sinus fairly deep, somewhat L-shaped. Sculpture of fine axial ribs crossed by slightly finer spiral threads, with small nodules at points of intersection; interstices with microscopic axial plicules; surface with a silky iridescence. Axial ribs thin, narrower than intervals, fairly sharp, opisthocline, arcuate, suture-to-suture on spire whorls, extending well on to base on body whorl, breaking up into a series of dense plicules behind lip; 28-30 ribs on 1st whorl, 28-39 on penultimate one. Spiral lirae narrower than their intervals, sometimes weak to absent around middle of body whorl, 7-8 on 1st whorl, 12-14 on penultimate one; subsutural lira demarcated by a deeper and wider groove which indents, but does not cut through, axial ribs to form an inconspicuous cingulum; base of body whorl with 17-20 lirae, subequal in strength and narrower than their intervals, becoming denser and somewhat stronger at end of rostrum.
Two colour forms: (a) yellowish-white, with two rows of small, diffuse, widely spaced spots of moderate orange on body whorl, the posterior one visible on penultimate whorl; (b) white with a series of large axial flames of brownish-orange on spire whorls and postperipheral part of body whorl, base of latter with more diffuse blotches; protoconch white. Protoconch as in brevispira; breadth 0,63-0,70 mm, height 0,38-0,53 mm (b/h 1,32-1,79). Dimensions: 4,6 x 2,0 mm (holotype); 4,2 x 1,9 mm, 5,2 x 2,1 mm (paratypes).

Similar to M. brevispira in general form and sculpture, but with a much higher spire, more numerous axials and spirals, and a different colour pattern; protoconch white, not yellow. Blotched individuals may have flatter whorls than normal but do not appear to be specifically separable.

Range: Transkei, outer continental shelf.