Shell acuminately, elongately fusiform ; fairly solid; of 7 whorls, including 2 nuclear; from the dorsal aspect the body whorl constitutes rather more than half of the entire length, and is very finely longitudinally and spirally striate. Columellar callosity starting from a little below the centre of the aperture, and extending across the body and penultimate whorls; well defined, but not conspicuously prominent, it has a peculiarly finely corroded appearance. An enamel band starts below the suture of the body whorl, and continues over the spire in a less pronounced manner. There are about five distinct, slightly punctured, encircling grooves on the penultimate and spiral whorls. The uppermost basal groove commences at the columellar callosity, a little below the centre of the body whorl, and terminates in a very slight projection of the outer lip ; after an interval this groove is followed by a second similar one, which has no projection on the lip, and terminates there a little above the notch ; this groove is followed by a well defined ridge, which is somewhat concave at the lip; this is caused by the backward effuseness of the notch; then follow about six ridges crossing the arcuately twisted columella, the uppermost ridge terminating about the centre of the notch. Aperture narrow lanceolate; outer lip acute, with a well defined sinus at its junction with the body whorl.The shell is creamy white, with a brown band immediately above the upper basal groove; sometimes the coloration is continuous, but the band usually consists of a series of blotches more or less coalescent; the enamelled band is coloured similarly, but in the form of dashes, which obliquely cross the suture and are there reversely bent, and continue thus round the spire, the intermediate marking between the bands on the body whorls are spirally zigzag, interrupted, and very light brown in colour. Length, 18 mm. ; breadth, 6 to 7 mm.; length of aperture, 9 mm. ; maximum breadth, 3 mm.

It is more narrowly acuminated, and the spire is proportionately more lengthy than in any other living species that we know of ; its nearest ally is A. lineata, Kiener, for which species it has been mistaken ; but it may be readily distinguished from it by its much more slender form and its numerous spiral grooves.

Australia. Habitat. Rosebud, Port Phillip, and Western Port.