Puncturella harrissoni (Beddome, 1883)
Description: Shell oval or elongate-oval, widest centrally, variable in height. Apex slightly behind centre, backward pointing and recurved. Anterior slope convex, posterior slope slightly concave. Slit at top, oval in shape. Septum internally, straight edged, occupying about one-eighth of shell height. Selenizone absent. Sculptured with 13-17 broad folds, weak or absent towards the apex. Margin crenulate by external folds. Colour white externally and internally.
Size: Up to 4 mm in length
Distribution: Endemic to Australia: Iluka, NSW, to Tasmania and SA
Habitat: Beach grit and intertidal algae washings, and down to 80 m. Moderately common.
Comparison: Distinguished from P. kesteveni by having the apex and slit central, the shell flatter with strong axial folds, and no scales.
Synonymy: Puncturella henniana Brazier, 1894
Remarks: This species shows some variation in shape, from low with an oval base (Fig. 2a) to tall with the base elongate (Fig. 2b). The axial folds do not start until half-way through shell growth in most specimens, so are absent in most juveniles.
Fig. 1 Collaroy Beach, NSW. (SEM photo Sue Lindsay) (C.335512)
Fig. 2 a. Collaroy Beach, NSW (C.335512) b. Off Port Stephens, NSW (C.370183) (SEM photo Sue Lindsay)
Copyright Des Beechey 2005