Figure 9. Holotype of Grzybowskia jasoni polished surface of hand specimen showing development of adult and gerontic stages. Alignment of primary chamberlets of equal height (three of which are marked with black squares) produces a spiral within the adult whorl. In the final, gerontic stage the multiple and irregular chamberlets form a more rapidly expanding rate of growth. Hand specimen number FFC H1. Maximum dimension on this specimen is 3.1 mm. Flying Fish Cove, Christmas Island.