defossa
Tongaporutian (Tt). Upper or lower not determined
Type Locality: NZ Fossil Record Number: X19/f7468 (holotype), X19/f7512 (paratype)
Type Locality; Latitude and Longitude: 38.89031°S 177.61085°E
Type Repository: GNS (but not in online catalogue)
Powell's (1942) description states
"Shell small, with depressed spire, which is less than height of aperture. Spire whorls showing a spiral row of blunt rounded nodules at each suture, 14-15 per whorl. Upper sutural row representing the subsutural fold; the lower sutural row being the peripheral crest of longish axials which occupy half the height of the base. The bottoms of these axials abruptly terminate at a deep, narrow median basal groove bordered below by a weakly nodulated spiral cord and followed distantly by a second one near the anterior canal. Axials weakly continuous across the broad shallow shoulder. Two very indistinct spiral cords cross the long basal axials."