Hygromia (Riedelia) limbata hylonomia (Bourguignat, 1882)

Hygromia (Riedelia) limbata hylonomia (Bourguignat, 1882)

( Fig. 7; Supporting Information, Figs S6–S 7)

Helio hylonomia Bourguignat, 1882: 69 , 315. Type locality: ‘Lourdes, dans les Hautes-Pyrénées; Lormont, près Bordeaux, dans la Gironde; vallée du Clain, près Poitiers, dans la Vienne’.

Type material: Te best-preserved specimen from Loudes is designated here as the lectotype MHNG-MOLL-116265 ( Fig. 7A), and two remaining specimens become paralectotypes. Hereby the type locality of H. hylonomia is restricted to Lourdes as the topotypes from Lormont genetically belong to H. limbata s.s. and those from Poitiers were not examined, but could presumably represent H. sublimbata . Since we provisionally synonymized H. veprium Bourguignat, 1882 with H. limbata , it was necessary to give H. hylonomia Bourguignat, 1882 priority over H. veprium Bourguignat, 1882 to avoid H. veprium threatening the use of H. hylonomia in the future if it should turn out to be a synonym of H. hylonomia .

Description

Shell width 11.5–15 mm, shell height 7.7–10.9 mm, whorls 5.1– 6.6. Other measurements are presented in Table 1. Shell shape from lenticular, as in the syntype, to globose. Convex spire with a prominent apex. Last whorl slightly or clearly keeled, usually with light band. Aperture moderately oblique with reflected whitish or pinkish lip. Umbilicus variously developed from completely closed (20% of cases) to open (46.5%) or at least partly covered (33.5%) by columellar margin. Shell sculpture unevenly disposed usually in a form of dense ridges ( Fig. 15A–D). Love dart thin, long ( 5 mm), and clearly curved with the crown only slightly expanded ( Fig. 21 I-K). Shell and genitalia features are presented in Table 2.

Distribution

In this study, recorded in Lourdes (the type locality) and the nearby mountains in the French central Pyrenees as well as one population in England ( Devon), altogether including eight populations ( Supporting Information, Table S 1; Fig. 1) .

Habitat

Found in France in humid and rocky habitats in high mountain valleys at altitudes of 400–1420 m a.s.l. (Supporting Information, Fig. S8). Te English population comes from a highly artificial environment, a small domestic garden with a litle shade .