Everettia occidentalis, Liew & Schilthuizen & Vermeulen, 2009

Liew, Thor-Seng, Schilthuizen, Menno & Vermeulen, Jaap Jan, 2009, Systematic revision of the genus Everettia Godwin-Austen, 1891 (Mollusca: Gastropoda: Dyakiidae) in Sabah, northern Borneo, Zoological Journal of the Linnean Society 157 (3), pp. 515-550 : 540-541

EVERETTIA OCCIDENTALIS SP. NOV.

Types: MALAYSIA: State of Sabah: Sipitang District. Upper Padas , forest patch near Long Pa Sia village . At 1200 m alt. (4°24 ′ N, 115°44 ′ E). Collected by T.- S. Liew and Meckson. Date: 17.vi.2006, holotype, BOR/ MOL 4345, Figure 2E ; eight paratypes, four in BMNH 20080632 and four in SP 13064 .

Etymology: This species is named occidentalis for its distribution range in the western mountain ranges of Sabah.

Material examined: SABAH – Crocker Range: BOR/ MOL 946, Lian cave, iv.2000. JJ 1087, Lian cave, vii.1986. Tenom: BOR/MOL 1373, Tenom Rafflesia Garden, 400 m alt., vi.2003; BOR/MOL 4244, 350 m alt., i.2006. Sipitang: BOR/MOL 2993, Muaya waterfall, Lumaku, x.2003.

Diagnostic characteristics: Regularly spaced radial grooves above shell which are different from the radial corrugation of E. dominiki .

Description: Shell ( Figs 2E , 11D ): medium-sized, rather thin, brownish, moderately elevated, outer whorls slightly shouldered below the suture. Periphery round to slightly angular. Above the periphery, shell shiny with rather regularly placed radial grooves, c. 2–4 per mm. These radial grooves make the shell seem sculptured with radial ridges under the naked eye. Below the periphery, shell has very fine, shallow, densely placed spiral grooves. Height up to 11.0 mm; width up to 13.0 mm; diameter of the first three whorls 0.9, 0.5, and 1.2 mm, respectively; number of whorls up to four and three-quarters; height aperture up to 4.9 mm; width aperture up to 6.8 mm. Genitalia: unknown. Animal: unknown.

Distribution and habitat: Primary forest. Sabah: Long Pa Sia, Tenom, and Sipitang, interior of Sabah ( Fig. 5A ).

Figures

Figure 2. Shells. A, Everettia corrugata corrugata; B, Everettia corrugata williamsi ssp. nov.; C, Everettia interior sp. nov.; D, Everettia jucunda; E, Everettia occidentalis sp. nov.; F, Everettia jucundior sp. nov. Scale bar = 10 mm.

Figure 5. Distribution maps (Sabah). A, Everettia subconsul in the east and west coast lowland, Everettia jucunda in the west coast, and Everettia occidentalis sp. nov. in the western mountain range; B, Everettia klemmantanica in the central mountain ranges, Everettia interior sp. nov. in the interior area, Everettia paulbasintali sp. nov. in the east coast lowland, Everettia themis in the central mountain ranges; C, Everettia lapidini sp. nov. in the central mountain ranges, Everettia jucundior sp. nov. in the east coast lowland; D, Everettia monticola sp. nov. in the central mountain ranges, Everettia planispira sp. nov. in the eastern and northern parts of Sabah.

Figure 11. Shell surface sculptures (scanning electron micrographs). A, upper surface of Everettia corrugata williamsi ssp. nov.; B, underside of E. corrugata williamsi ssp. nov.; C, underside of Everettia lapidini; D, upper surface of Everettia occidentalis sp. nov.; E, corrugation at the suture of Everettia corrugata corrugata; F, upper surface of Everettia jucundior sp. nov. Scale bar = 500 Mm.