Shell ovate-fusiform, solid, up to 42 mm in length; width 33-40% of shell length. Protoconch not preserved in type specimens. Teleoconch with up to 8 rather straightsided, slightly convex whorls which are subangulate at the sutures, each whorl sculptured by distinct fine spiral grooves and wider axial furrows, resulting in a coarsely nodulous surface; distinct fossuies are developed where the spiral grooves and axial furrows intersect; spiral grooves more regularly spaced than the axial furrows, accordingly the beaded spiral cords are rather equal in width, wheras the beaded axial folds are more irregular in width. Some of the axial folds are stronger than the neighbouring ones. Sutures distinct, whorls faintly beaded anterior to the sutures. Penultimate whorl with 5-7 spiral cords and 30-40 axial folds. Body whorl with 17-19 spiral cords (apart from the siphonal fasciole with 4-5 densely arranged oblique cords) and 30-40 axial folds, the latter becoming very narrow growth rolls towards the aperture in fully adult specimens. Aperture slightly shorter or longer than the spire, relatively narrow, particularly at the slit-formed posterior part, smooth within, outer lip moderately thickened and only slightly crenulate, inner lip well protruding at the anterior half in adult specimens. Columella with four or five rather weak plaits, no callus in the posterior aperture angle, siphonal notch deep and wide. Fresh specimens dark to moderate brown, with a distinct broad whitish zone on the body whorl, this striking whitish zone comprising six spiral cords below the posterior aperture angle. Within the brown-coloured parts of the shell some of the beads and nodules are dotted white, in particular the occasional stronger axial folds are strikingly white, and many spiral grooves are underlined darker brown; columella and aperture light brown to beige. Periostracum thin, colourless and translucent.

M. (M.) leforti n. sp. was first illustrated by Heinicke (1980) as an unidentified shell which he compared to Mitra (M.) puncticulata Lamarck, 1811 and more closely to a shell which was illustrated by Kaicher (1977: card 1468) as „Scabrico!a lacunosa (Reeve)". [The true identity of Kaicher's shell (from East Africa? Natal Mus. 61296) remains doubtful, but it is certainly not conspecific with M. leforti n. sp.]. In the opinion of Cernohorsky (1980) the „mystery mitre" of Heinicke „falls within the range of known variability of Mitra lacunosa Reeve, 1844".
M. {M.) leforti n. sp. is similar to M. (M.) nympha Reeve, 1845 in size and shape. M. nympha differs however in having a much smoother shell surface and a wider aperture. In addition, M. nympha shows a different colour pattern with a creamy-yellow or light orange base colour, lacking the broad whitish zone on the body whorl (so strikingly evident in M. leforti n. sp.), but shows a spiral row of alternate brown and white nodules anterior to the sutures; the columella and aperture are white.
M. leforti n. sp. was on the other hand also confused with M. (M.) lacunosa Reeve, 1844 . Reliable distinctive features are that M. lacunosa shows strongly rounded to angulate presutural ramps of the whorls, lacks a pustulate sculpture, and is white or cream in colour with some large brown blotches on the spire whorls and 1-2 broad brown zones on the body whorl.
It was also suspected that M. leforti n. sp. could be M. abacophora Melvill, 1888, a taxon which was never carefully reviewed and never illustrated since its original description (from unknown locality), but was put with some uncer¬tainty into the synonymy of M. {M.) bovei Kiener, 1838 by Cernohorsky (1976a: 311). Evidently this is a quite different species, having practically nothing in common with M. leforti n. sp. nor with M. bovei, but has to be taken as a species in its own right. Communication with Richard Salisbury, a prominent connoisseur of Mitridae, has lead to the conviction that James Cosmo Melvill had written correctly in his original description of M. abacophora („the board-bearing mitre"): „This interesting shell is one of the subgenus Strigatella (Swn.)...". It became also evident that M. abacophora is an earlier name of M. (Strigatella) nebrias Melvill, 1895 (type locality: Aden).

Type locality
Southwestern Madagascar: Tulear (= Toliara, 23°21'S, 43°40'E).

Distribution and habitat:
Reliably known only from southwestern and southern Madagascar (doubtful other locations are South China Sea and the Philippines). In subtidal water, on bottoms of sand and rubble.