Dicharax ebrius Pall-Gergely & Auffenberg 2021, n. sp.
Creators: name: Páll-Gergely, Barna
name: Hunyadi, András
name: Grego, Jozef
name: Reischütz, Alexander
name: Auffenberg, Kurt
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Architaenioglossa
Cyclophoridae
Dicharax
Dicharax ebrius

description: Dicharax ebrius Páll-Gergely & Auffenberg n. sp.
Fig. 21
Material examined. Holotype: Thailand, Mae Hong Son Province, 42 km NW of Pai, Road 1095, 19°32’N, 98°32’E, 750 m a.s.l., 20 Mar. 1988, K. Auffenberg leg., UF 345577 (D: 2.89 mm, H: 1.97 mm). Paratypes: 22 shells, same data as holotype, UF 551221. Other material: 9 juvenile shells, same data as holotype, UF 551222.
Etymology. The dorsal view of the shell of this new species looks like a face of a drunken (ebrius in Latin) man due to glossy R3 swelling.
Diagnosis. A small Dicharax species with a finely ribbed R1, glossy swelling on R3 situated far from peristome, thickened outer peristome and slightly fringed inner peristome.
Description. Shell off-white to yellowish corneous, slightly translucent; shell outline slightly oval in dorsal view; spire slightly elevated, low conical, body whorl rounded; protoconch low, glossy, 1.25–1.5 whorls; R1 of 1.75–2 whorls, finely, regularly ribbed from beginning, ribs gradually become more widely-spaced toward R1 termination; boundary between R1 and R2 conspicuous due to dense R2 ribs; R2 ribs curved toward aperture, ca. 44–46 ribs present; R2 ribs almost adnate; R2+R3 slightly more than quarter whorl (ca. 100˚); R2 approximately as long as R3 or slightly shorter; boundary between R2 and R3 distinct due to change in sculpture and deep constriction; R3 with prominent, but rounded, glossy swelling situated close to constriction; between swelling and peristome with few fine ribs, in some specimens this area slightly swollen, seemingly forming secondary swelling; aperture strongly oblique to shell axis, rounded with basal incision; boundary between inner and outer peristomes indistinct; inner peristome strong, protruding, expanded, basal and palatal portions slightly fringed, outer peristome expanded, and reflected toward umbilicus; peristome edges merge to form a multi-layered, thickened apertural lip; umbilicus narrow, approximately one fourth of shell width.
Measurements. D: 2.65–2.89 mm, H: 1.85–1.97 mm.
Operculum. Outer surface concave, yellowish corneous, with some traces of a deciduous lamina; inner surface with a small, pointed, low central nipple.
Differential diagnosis. The small shell size, blunt, but prominent, glossy swelling on R3 makes this new species easy to recognize. Dicharax notus (Godwin-Austen, 1914) is similar in overall shell shape, but has blunter, less glossy R3 swelling situated closer to peristome and a rounded aperture.
Due to the weak traces of lower, secondary R3 swelling and overall shell shape, this new species is similar to D. birugosus (Godwin-Austen, 1893) (syn. Alycaeus canaliculus Godwin-Austen, 1914, see Páll-Gergely et al. 2020) from the Khasi Hills, India. However, the Indian species has shorter R2 and R3, the R2 ribs are more widely-spaced, and prominent secondary swelling.
Distribution. This new species is known only from the type locality (Fig. 17).
description: Published as part of Páll-Gergely, Barna, Hunyadi, András, Grego, Jozef, Reischütz, Alexander & Auffenberg, Kurt, 2021, Nineteen new species of Alycaeidae from Myanmar and Thailand (Gastropoda: Caenogastropoda: Cyclophoroidea), pp. 1-61 in Zootaxa 4973 (1) on pages 28-29, DOI: 10.11646/zootaxa.4973.1.1, http://zenodo.org/record/4771958