Brookula nepeanensis (Gatliff, 1906)
Description: Shell minute, height to width ratio variable in range 1.3 - 1.5. Protoconch smooth, elevated. Teleoconch up to 4 whorls, suture deep. Sculpture fairly constant; axial sculpture of strong, crisp ribs on all whorls, 13-17 on last whorl, strong on periphery, weaker on base. Fine spiral threads over whole surface between axials, about 12 on second-last whorl, finer and more numerous on base. Umbilicus almost closed. Aperture circular, margin entire, not thickened. Shell colourless translucent when fresh, becoming opaque white with age.
Size: Up to 1.6 mm in length.
Distribution: Endemic to Australia: Port Stephens, NSW, southwards to SA, including Tasmania.
Habitat: NSW specimens are from beach washup and dredgings down to 20 m, but the Australian Museum holds one Tasmanian lot from 113 m and one SA lot from 183 m. Moderately common.
Comparison: See B. angeli.
Synonymy: Brookula jacksonensis Laseron, 1954 (Fig. 3) falls within the range of variation of this species (NEW SYNONYM).
Fig. 1, 2: Port Stephens, NSW (C.462817) (Photos Sue Lindsay, Australian Museum)
Fig. 3: Syntype of Brookula jacksonensis (C.102819) (Photo Sue Lindsay, Australian Museum)
Copyright Des Beechey 2009