Diversity of the extinct land snail genus Chilonopsis of St Helena (Mollusca: Gastropoda: Achatinidae) Author Gerlach, Justin Peterhouse, Trumpington Road, Cambridge CB 2 1 RD, UK. jg353@cam.ac.uk Author Griffiths, Owen Bioculture Ltd, Seneville, Rivière des Anguilles, Mauritius. & Being formed from volcanic activity around 14 Mya, its non-marine snail fauna comprises colonising species and, being so isolated, few species are present, derived from even fewer colonisations. owen@bioculturegroup.com Author Hume, Julian P. Bird Group, Natural History Museum, Akeman Street, Tring, Herts HP 23 6 AP, UK. j.hume@nhm.ac.uk Author Louchart, Antoine Univ. Lyon, Univ. Lyon 1, ENSL, CNRS, LGL-TPE, Villeurbanne, France. antoine.louchart@ens-lyon.fr Author Sorrel, Philippe Univ. Lyon, Univ. Lyon 1, ENSL, CNRS, LGL-TPE, Villeurbanne, France. philippe.sorrel@univ-lyon1.fr Author Cairns-Wicks, Rebecca Saint Helena Research Institute, Jamestown, St Helena Island, South Atlantic Ocean. rebecca.cairns-wicks@sainthelena.gov.sh text European Journal of Taxonomy 2025 2025-08-13 1007 176 210 https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3007/13499 journal article 311842 10.5852/ejt.2025.1007.3007 0650a04b-15ea-42d9-abf0-49975fa35c44 2118-9773 16903013 2E51A197-E08C-4A68-9E4E-A93AEF3CD8B2

Table 1. Measurements (means ± standard deviation in mm) and proportions of shells of Chilonopsis Fischer von Waldheim, 1848.

	height		diameter		height/diameter		mouth height/ width		n
	range	mean	range	mean	range	mean	range	mean
aurisvulpina	33.1–48.8	42.20 ± 4.26	20.1–31.5	25.57 ±3.50	1.52–2.00	1.67	1.40–2.10	1.79	34
helena	15.1–22.3	18.29 ± 1.61	7.4–12.7	9.50 ±1.04	1.64–2.20	1.91	1.48–1.80	1.71	119
blofeldi	25.9–30.2	28.30 ±1.40	14.1–17.1	15.59 ±1.09	1.68–2.04	1.82	1.52–1.85	1.72	7
lanceoloideus sp. nov.	15.9–21.3	17.76 ± 1.67	10.1–12.1	11.09 ± 0.76	1.51–1.76	1.605	1.63–1.93	1.80	10
exulatus	17.2–21.5	19.83 ±1.41	7.5–9.2	8.63 ±0.52	2.24–2.39	2.30	1.63–2.25	2.13	8
subtruncatus	29.0–31.5	29.95 ±1.17	12.5–14.2	13.30 ±0.88	2.17–2.23	1.82	1.66–1.97	1.77	5
subplicatus	17.0–25.4	20.05 ± 3.63	5.3–9.2	7.57 ± 1.45	2.15–3.24	2.79	1.79–1.99	1.91	31
melanioides	23.8–24.8	24.23 ±0.51	7.4–8.0	7.77 ±0.32	3.01–3.22	3.12	1.44–1.95	1.72	4
turtoni	14.7–18.4	16.22 ±1.47	8.1–9.2	8.37 ±0.52	1.67–2.10	1.92	1.31–1.78	1.63	9