Shell large and very solid, ca 97 mm. (33/4 inches) in height, fusiform, with tall turreted spire and long, rather narrow body-whorl, gradually tapered to a stout, almost straight, widely open, moderately long, unnotched anterior canal. Whorls 7+, protoconch and early spire whorls eroded away. Spire whorls medially angulated, early ones with broadly rounded oblique axial folds, abruptly stopped at the angulation, about ten per whorl. The axial folds become subobsolete from the commencement of the penultimate whorl, after which they are represented by strongly protractively arcuate, rather irregular folds, which commence strongly at the peripheral angle but rapidly fade out over the base. Aperture long and narrow; inner lip almost straight in profile; outer lip thin edged; posterior sinus deep, U-shaped, with a broadly rounded apex and occupying almost the lower two-thirds of the steeply descending, rather straight, shoulder slope; lower edge at the peripheral angulation. Lower part of outer lip produced forwards in a broad sweeping arc. Colour dull white, interior of aperture and parietal callus porcellanous-white. Surface of shell crowded with fine spiral threads. Operculum lanceolate, tapered below to a long straight gradually-tapered point (30 X 8 mm.) ; that of kaderlyi is normal leaf-shaped and proportionately much broader (16 x 7 mm, in a shell 74 mm. in height). Animal with cephalic tentacles broad-based and short, each with a prominent eye, stepped on the outer edge about one third way-down from the blunt tip. Penis flattened, very long (ea 45 mm.), gradually tapered to a fine point. Holotype: height 94 mm, width 31 mm.

Only a single specimen of this shell is known. Allowing for probable gerontic tendencies, the Aru Islands shell appears to stand outside the range of variation acceptable for kaderlyi. When compared with kaderlyi of equal size the Aru shell is shown to have a longer and narrower aperture, a more gradually tapered body-whorl, an almost straight columella + parietal wall profile, medially carínate late whorls accompanied by subobsolescence of the axial sculpture, and a deep U-shaped posterior sinus, which has a much wider, more broadly rounded apex, occupying the lower two-thirds of the shoulder slope. Confirmation that the Aru shell is not merely a gerontic kaderlyi is furnished by the operculum, which is lanceolate in galatheae but broadly leaf-shaped in kaderlyi.

Off Aru Islands, Indonesia in 352 metres.