Mauidrillia trispiralis
Shell very slender, sculptured with relatively few strong spirals which are rendered nodulose at the axial intersections. Subsuturai fold strong, 2 to 3 threads on shoulder ; peripheral carina and two cords below it, all equally strong. About 19 cords on body- whorl from periphery to the anterior end. The holotype exhibits abnormal sculpture on the front of the body-whorl, due to a shell injury and its subsequent repair. Axiais 13 per whorl, producing nodulation where they cross the three main spirals. Body-whorl crossed by numerous axial riblets which render the spirals weakly crenulate. The absence of strong axial nodulation on the body-whorl may be due to the shell injury already mentioned.
Height, 9.9 mm.; diameter, 3.5 mm.
Locality: Gellibrand River, Victoria (Finlay coll.) (Janjukian) Lower Miocene.