DESCRIPTION: Shell elongate, fusiform with regularly convex whorls cut by a prominent keel. Protoconch of 1,5 to 2,5 whorls, usually keeled, the first usually larger than the remainder, deviated at a low angle to the axis of the spire and flattened, second whorl either merging gradually with the spire whorls or ending abruptly, sometimes with a small varix or midwhorl nodule. Spire whorls convex, sculptured with prominent spiral lirae and often broad low axial ribs or folds. Keel prominent, rarely obsolete, occasionally produced into a flange but usually in the form of flattened blunt triangular projections. Aperture subtriangular with the inner lip coated with a thin glaze. Canal long and straight or very slightly twisted.
STRATIGRAPHIC RANGE: Middle Eocene, Lower Oligocene, Europe; Lower Oligocene—Recent, New Zealand; Recent, Africa.
DISTRIBUTION: Europe, New Zealand, South Africa, West Africa.

The protoconch of Coluzea is somewhat variable from species to species when compared with other columbariids, though most seem to be of the form of C. dentata (Hutton) rather than C. spiralis (A. Adams). The latter has a prominently keeled protoconch which merges gradually with the spire whorls, unlike most of the other species, which either end abruptly as in C. mariae Powell or end in an incipient varix or small ribs as in C. dentata (Hutton). C. climacota (Suter) is not a columbariid since the protoconch is rather different from all the others in having more whorls and a more prominent midwhorl keel which spirals to the anterior suture and forms the sutural lira, whilst another midwhorl keel develops from a series of small midwhorl nodules.
The South African species described below were originally thought to be related to the Australian Serratifusus but on examination of specimens now in hand it appears that their affinities are more with Coluzea. They lack the prominent triangular keel spikes of the former and also the prominent axial plicae of the protoconch, though the specimens examined are worn. Moreover, they lack the prominent axial costae of the early spire whorls which is so typical of Serratifusus. The radulae and opercula of the four species are typical of the family.
The authorship and type species of Coluzea is in dispute due to an inadvertent appearance of the name in a list prior to the original description, and the settlement of this problem will probably be a matter for the International Commission on Zoological Nomenclature. Fortunately the existence of this problem does not affect the concept of the genus, as both 'type' species are very similar in morphology and are closely related.