Rixa watsoni (Brazier, 1894)
Description: Shell elongate-oval, parallel-sided centrally. Apex near posterior margin in juveniles, moving to slightly behind center in adults; backwards pointing and recurved. Anterior slope convex, posterior slope straight below apex. Slit at top centrally, "U" or rounded "V" shaped. Septum internally, straight edged. Selenizone a triangular band from apex to front of septum. Sculptured with beaded radial ribs and foliaceous concentric ribs. Colour translucent white, sometimes with brown patches at the margin.
Size: Up to 6 mm in length.
Distribution: Endemic to Australia: Laureton to Twofold Bay, NSW.
Habitat: Beach grit and down to 73 m. Uncommon.
Fig. 1 Manly, NSW (C.443978) (SEM photo Sue Lindsay)
Copyright Des Beechey 2005