A revision of the Chilodontidae (Gastropoda: Vetigastropoda: Seguenzioidea) of southern Africa and the south-western Indian Ocean Herbert, D. G. African Invertebrates 2012 2012-11-06 53 2 381 381 7P53Y 479590 : Pilsbry 1890 [451,605,204,229] Gastropoda Chilodontaidae Herpetopoma Animalia Seguenziida 48 429 Mollusca genus    1 Basal columella tooth a well-developed peg with a deep U-shaped notch separating it from the first (usually the largest) tooth inside the basal lip ( Fig. 23)................2  – Basal columella tooth smaller and roundly trigonal; U-shaped notch at base of columella relatively shallow ( Fig. 32).......................................................................5   2 Umbilicus remaining patent in adult......................................................................3  – Umbilicus closed in adult.......................................................................................4    3 Adultshell length exceeding 5.0 mm; spire trochiform, usually with reddish brown markings................................................................................................. instrictum  – Adult shell length less than 4.0 mm; spire low, evidently without colour pattern... ........................................................................................................... seychellarum   4 Shell small, adult length rarely>3.0 mm; profile globose with a well-developed serrate spiral cord at periphery; coast of tropical East Africa ........ serratocinctum  – Shell larger, adult length>3.0 mm; spire profile more trochiform; peripheral cord not enlarged or conspicuously serrate; Mascarene Islands ......................... stictum   5 Sculpture relatively coarse with 3 strong spiral cords above and including periphery; beads on spiral cords axially elongate............................................................. helix  – Sculpture fine with 4 or more spiral cords above and including periphery; beads more or less rounded..............................................................................................6   6 Shell relatively low-spired, L/D<1.23; labral denticles largely restricted to thickened inner lip; whorls rounded, sculpture relatively coarse .............................? naokoae  – Shell higher-spired, L/D>1.23, some labral denticles extending into aperture as in-running ridges; whorls rather flat-sided, sculpture fine ....................... xeniolum