Broadly biconic-claviform with sharp, orthoconoid spire (breadth/length 0.42-0.52), and relatively wide aperture (aperture/total length 0.35-0.40), evenly truncate base, termination of siphonal canal concavely indented; fasciole strong; suture narrowly undercutting succeeding whorl, irregularly undulating. Outer lip somewhat alate below anal sinus, in side view rather weakly convex, serrated, anal sinus openly U-shaped, directed adapically, parietal nodule large, stromboid notch distinct but shallow; columella with a wide, rounded callus.
Subsutural region adpressed to base of previous whorl, sloping; axial ribs extending from suture (where they form weak folds) to periphery, where they form projecting, slightly outwardly directed, squamiform spines (sometimes merely angular nodules); seven arcuate, suture-to-suture ribs on first teleoconch whorl, 8-11 ribs on later whorls, spines in t/s sharp, with high, scale-like tips, steeply sloping, concave sides, near base on early whorls, median on penultimate one; sometimes a low ridge joining spines. Last whorl with a broad zone of coarse granules extending from periphery to parietal level and even rostrum; granules usually aligned spirally as well as obliquely, into bifurcating or vermiculate lines, sometimes forming distinct ridges. Base often with a row of prominent granules at level of anterior edge of parietal tubercle. Surface with a microsculpture of collabral threads and extremely fine, irregularly sloping spiral striae. Rostrum with 5-7 declivous spiral ridges.
White, with a broad deep orange-brown zone at mid-last whorl, sometimes with a darker border above, aperture (including parietal pad) white. Occasionally speckled overall with pale reddish-brown, with a dark brown band below periphery, interrupted by bases of ribs. Protoconch dark yellowish-brown, contrasting with the white teleoconch whorls that follow.
Protoconch narrowly domed, of about two smooth whorls (under SEM a series of very fine plicules visible below suture); breadth 830 µm, height 630 µm.
Measurements. 23.4 x 10.9 mm (largest available); smallest adult 14.1 x 8.3 mm; 15.8 x 7.3 mm (narrow example).
Radula. Not available.

This species is highly variable, not only in colouration and adult size but in the development of its shoulder tubercles. When unworn, the latter may be almost as prominent as in typical examples of Clavus canalicularis, yet in other individuals they are scarcely stronger than in C exasperatus. C. rugizonatus is characterised by its strongly granulose and pustulose basal zone. The combination of variously sized and shaped pustules, together with the crispate growth lines, give the base of the last whorl a curiously rasp-like appearance.
Other than a single unconfirmed specimen from Hawaii in the NMSA, this species is known to us only from New Caledonia.

The species can be differentiated from its congeners in the Clavus canalicularis complex by the combination of strongly -pronounced nodes situated at the mid-height of whorls, and the presence of a distinct yellow to light-brown band and 3-4 rows of spirally aligned nodules on the shell periphery.

New Caledonia, Loyalty Islands and Coral Sea, 1—70 m, mainly in sediment and sand between coral on reef bottoms, no live collected specimens were available, but the shells collected below 40 m were strongly worn and probably occurred there due to vertical transposition. Also New Ireland.