DIAGNOSIS: A Columbarium with a gradate spire and a thin foliaceous extension of the keel, posterior whorl slope smooth, anterior slope bearing the anterior carina only. Canal lirae with numerous small spines.
DESCRIPTION: Shell with a gradate spire and a large globose somewhat flattened protoconch. Spire whorls with a well developed shoulder and unornamented except for growth lines. Keel produced into a thin slightly upturned flange which has irregular extensions at the extremity. Anterior whorl slope of the body whorl with the anterior carina only. Canal bearing about eight regularly spaced spinose lirae

The whorl shape, the presence of the typical anterior carina and the globose deviated protoconch are similar to other species of Columbarium. However in this species the keel flange present on the early whorls has continued on the adult and has not broken into a separate series of triangular spikes as in other species of the genus. On the specimen examined the outer extremity of the flange near the aperture has a somewhat serrated outline due to the incipient development of spikes. A similar development of the keel has taken place in Serratifusus joliaceus (Tate).
This species has not been found since the original Challenger material was collected and its occurrence off Sydney has been doubted, as some species recorded from station 164B are Atlantic species. However, because of its close relationship with other Australian living and fossil species of Columbarium, and because it was dredged from deep water which has not yet been adequately explored, the author is of the opinion that it is an indigenous species.

LOCATION OF TYPES: British Museum (Natural History): Lectotype here selected, the specimen originally figured by Watson 1887.2.9.688; Australian Museum, Sydney: Paratype C2965.
TYPE LOCALITY: Challenger station 164B, June 13, 1874. Lat. 34°13'S., Long. 151°38'E. 410 fathoms, off Sydney.