Everettia corrugata WILLIAMSI 2009, SSP. NOV.
Creators: name: Liew, Thor-Seng
name: Schilthuizen, Menno
name: Vermeulen, Jaap Jan
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Stylommatophora
Dyakiidae
Everettia
Everettia corrugata

description: EVERETTIA CORRUGATA WILLIAMSI SSP. NOV. <i>Types:</i> MALAYSIA: State of Sabah: Ranau District. Southern part of Kinabalu Park. At 3100 m alt. along Kotal’s route from Bukit Babi to eastern ridge of Mount Kinabalu (6°4 <i>′</i> N, 116°36 <i>′</i> E). Collected by T.- S. Liew, J. Lapidin, Safrie, and Jasilin. Date: 23.iv.2005; holotype, BOR/MOL 5297, Figure 2B; four paratypes, two in BMNH 20080625 and two in SP 13057. <i>Etymology:</i> This species is named after Dr Peter Williams (Oxford), who did the first malacological survey for Mount Kinabalu’s eastern ridges during the Cambridge Kinabalu Expedition in 1967. <i>Material examined:</i> SABAH – Mount Kinabalu: BOR/ MOL 5295, eastern slope, 2812 m alt., iv.2005; BOR/ MOL 5296, eastern slope, 2676 m alt., iv.2005; BOR/MOL 5298, eastern slope, 2992 m alt., iv.2005; BOR/MOL 5299, eastern slope, 3064 m alt., iv.2005; BOR/MOL 5300, eastern slope, 2280 m alt., iv.2005. <i>Diagnostic characteristics:</i> Shell above with regularly and densely placed radial threads and cut by widely spaced spiral grooves. <i>Description:</i> Shell (Figs 2B, 11A, B): medium-sized, rather thin, greenish brown, moderately to distinctly elevated, outer whorls slightly shouldered below the suture. Periphery rounded. Above the periphery, shell with a silky lustre, regularly and densely placed, distinct radial threads and cut by widely spaced spiral grooves. Strong corrugation just below the suture. Below the periphery, shell has very fine spiral grooves (more conspicuous than in <i>Everettia corrugata corrugata</i>). Height up to 11.3 mm; width up to 18.3 mm; diameter of the first three whorls 1.2–1.4, 0.9–1.1, and 1.6–1.8 mm, respectively; number of whorls up to five; height aperture up to 7.7 mm; width aperture up to 9.8 mm. Genitalia: maximum length from genital opening to the end of dart-sac (before the visible gland tubules) up to 11.5 mm. The penis, dartsac, and vagina with thick muscular walls. P, V arranged near the GO then followed by BC and DS where there is little space in the atrium between the openings of P + V and BC + DS. BC about two-thirds of total DS length. Animal: animal head uniform black or grey and extended backward to the end of mantle and downward to the foot-fringe. A grey smear covers large parts of the animal and extends to the end of the tail. The mantle is covered with sparsely distributed bright spots. These bright spots become denser and are agglomerated with the black spots at the last half whorl. <i>Distribution and habitat:</i> Upper montane primary and coniferous forest, 2800–3500 m alt. Sabah: Mount Kinabalu (only found along the south-eastern slope), endemic (Fig. 9D). <i>Remarks: Everettia corrugata corrugata</i> and <i>Everettia corrugata williamsi</i> occur allopatrically at approximately the same elevational zone (2800–3500 m) but on different ridges which are separated by a deep valley.
description: Published as part of <i>Liew, Thor-Seng, Schilthuizen, Menno &amp; Vermeulen, Jaap Jan, 2009, Systematic revision of the genus Everettia Godwin-Austen, 1891 (Mollusca: Gastropoda: Dyakiidae) in Sabah, northern Borneo, pp. 515-550 in Zoological Journal of the Linnean Society 157 (3)</i> on page 534, DOI: 10.1111/j.1096-3642.2009.00526.x, http://zenodo.org/record/5443023