Rishetia subulata Budha & Naggs

Budha, Prem B., Naggs, Fred & Backeljau, Thierry, 2017, Conchological differentiation and genital anatomy of Nepalese Glessulinae (Gastropoda, Stylommatophora, Subulinidae), with descriptions of six new species, ZooKeys 675, pp. 129-156 : 137-138

Rishetia subulata Budha & Naggs sp. n. Figs 2J, 11

Material examined.

Holotype: CDZMTU072P/1 specimen (dissected), Godawari, along the Godawari-Phulchowki road, approx. 200 m above the Naudhara Temple, 1837 m, 27.5766N, 85.3786E, 02.X.2008, leg. P.B. Budha. Paratype: CDZMTU072/1 shell (same locality). Paratypes: CDZMTU073/3 shells, Phulchowki Hill, Central Nepal, mixed forest, 2324 m, 27.578317N, 85.396885E, 04.V.2007, leg. P.B. Budha and R. Devkota.

Distribution.

Only known from the type locality.

Etymology.

The name refers to the typical subuline-like shell shape.

Shell.

Measurements (n = 3): SH 10.8-14.9 mm, SW 3.6-4.1 mm, HA 3.3-3.5 mm, WA 1.8-1.9 mm, Wh 9.0-9.5; holotype: SH 10.8 mm, SW 3.6 mm, HA 3.3 mm, WA 1.8 mm, Wh 9.0; approx. 3.1 × higher than wide, elongated, thin, dull brown. Surface shining obliquely striated, covered with thin transparent epidermis, slightly denser on the 3rd and 4th whorl; transverse sculpture more widely separated on the penultimate and body whorls. Whorls shouldered. The first whorl blunt and smooth, eroded. Sides rounded; suture deep. Aperture ovate elliptical, approx. 2 × higher than wide, peristome thin, columellar margin calloused whitish, slightly truncate at the base.

Radula

(Fig. 13D). Central tooth very small, lacks cusps, lateral teeth tricuspid.

Animal.

Dark grey and papillate.

Genitalia

(n = 1) (Fig. 11). Vas deferens very long, enters into the epiphallus at some distance from the base of the flagellum. The flagellum is long and C-shaped. Epiphallic caecum very short. Epiphallus approx. as long as the penis. The basal part of the penis is comparatively wider than the proximal part. The penial retractor muscle far apart from the flagellum. Gametolytic sac elongated. The vagina is nearly as long as the penis. Albumen gland elongated and hermaphrodite duct is connected at the middle of the gland.

Remarks.

R. subulata sp. n. is similar to R. hastula (Benson, 1860) and R. tribhuvana sp. n., but R. subulata sp. n. has a wider body whorl and more blunt first whorl than R. hastula , while its 2nd and 3rd whorls have equal diameters (unequal diameters in R. hastula ) (Fig. 2 D1 and J1). The body whorl in R. subulata sp. n. is much wider than in R. tribhuvana sp. n. (Fig. 2 J and K). Moreover, the flagellum of R. subulata sp. n. much larger than the epiphallic caecum, whereas in R. tribhuvana sp. n. the flagellum and epiphallic caecum are of similar sizes. In R. hastula the flagellum and the epiphallic caecum are very small.