Vilertia galeata sp. nov.

Fig. 1-3

Type material: Holotype in MNHN Paris, #MNHN-IM-2000-38095 . Paratypes: 2 shells in MNHN Paris, #MNHN-IM-2000-38096, 2 shells in PG coll., 10 shells in SQS coll .

Type locality: Deu d’en Roure (= Deu d’en Costei), Esponellà ( Pla de l’Estany, Girona province) located in the Fluvià River basin (Fig. 4 & 5) Coordinates: 31TDG 82054700. 115 m a.s.l.

Other localities: Font de Beu i Tapa, Vilert (Pla de l’Estany, Girona province), also in the Fluvià River basin. 31TDG 85341691. 90 m a.s.l.

Description: Small shell, with valvatiform shape, 0.51 - 0.74 mm in height and 0.96 -1.13 mm diameter, with 3 whorls, deep sutures, and translucid coloration in freshly-collected specimens (Fig. 2, 3, 6). Protoconch microsculpture is formed by irregularly arranged microdepressions (Fig. 1 C-D). Teleoconch showing growing lines. Deep and wide umbilicus, ovoid aperture, about 0.60 -0.80 mm high and 0.51 -0.66 mm wide, slightly oblique, and having a sharp peristome, slightly reflected towards the columella, and strongly towards the outer lip. Last whorl represents 90 % of total height. Corneum operculum, with orange to yellow coloration, convex in the inner side (see Fig. 1E, 3D).

Animal: The animal is colorless, and the eyes are missing. The penis is broad and rounded at the tip with a penial lobe of the same length (Fig. 3B). Intestine with one loop (Fig. 3C). Female sex tract with spherical bursa, receptaculum could not be found.

Etymology: The specific name refers to the helmetshape of the shell, resembling the M15 Adrian French model of World War I.

Dimensions: The holotype is 1.05 mm in diameter and 0.68 mm in height. Paratypes range from 0.96 - 1.27 mm in diameter and 0.51 - 0.74 mm in height (see Table I).

Habitat: Stygobiotic, all the shells were collected from sediments at the opening of the springs.

Distribution: Only known from two different springs, very close to each other, in the margins of the Fluvià River.

Differentiating characters: Vilertia gen. nov. differs from all valvatoid genera by the reflexed peristome. It differs from Rifia Ghamizi 2020 by the missing outgrowth at the operculum; from Fissuria Boeters, 1991, by the penis, which is papillose but without a penial lobe. In addition, Fissuria has two intestinal loops, while Vilertia gen. nov. has only one.