Finella pupoides A. Adams, 1860
Description: Shell variable in shape, size and sculpture, with spire slightly convex in outline. Protoconch of 2-2½ whorls, ending with a strong varix on upper half of whorl, while lower half of whorl continues with ridge parallel to suture for up to half a revolution. Teleoconch of 5-6 whorls, sculptured with spiral threads, 7-9 on second last whorl, and irregularly spaced axial folds, usually fading out by last whorl. Aperture ovate, without anterior or posterior canal; outer lip simple, not thickened. Colour white or fawn, sometimes with a spiral fawn band near middle of whorls.
Size: Up to 4 mm in length.
Distribution: Indo-West Pacific. In Australia, from Esperance, south-western WA, around northern Australia to Sydney, NSW.
Habitat: In estuaries, lower intertidal and subtidal, down to 37 m. Common in the tropics, decreasing in abundance to end of range at Sydney.
Comparison: This is a nondescript species, best identified by the characters of the protoconch, although that is usually worn in dead collected shells.
Synonymy: Obtortio lutosus Hedley, 1915 is a synonym, based on a shell (Fig. 2) that is typical of the species in NSW (NEW SYNONYM).
Remarks: NSW shells are relatively slender for the species, and the axial sculpture is weak or absent. Fig. 1 shows two specimens from the same lot, illustrating the variation in shape.
Fig. 1: 4796-1 Cronulla, NSW (C.unreg, both specimens)
Fig. 2: 4798-1 HOLOTYPE of Obtortio lutosus. Middle Harbour, Sydney, NSW (C.32628)
Copyright Des Beechey 2014