Everettia themis
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 themis

description: EVERETTIA THEMIS (SMITH, 1895)   
 Xesta themis (Smith, 1895: 100), plate 2, figures 1, 2. Nanina (Xestina) themis, Kobelt (1905: 994), plate   
257, figures 10, 11.  
 Type material: BMNH 1894.7.21.112/1894.7.203-4, Holotype (seen).   
 Material examined: SABAH – Crocker Range: SP 12599, Ulu Kimanis, ix.2005; SP 12788, Ulu Kimanis, iv.2006. Mount Kinabalu: SP 12359, Bundu Tuhan Trail, xii.2003; SP 12360, Bundu Tuhan Trail, xii.2003; SP 12813, Bundu Tuhan Trail, vii.2006; BMNH 20080215, southern slope, 2000 m alt., 1967. Diagnostic characteristics: This species is easily recognized by its reddish keeled shell (for the Crocker range population) or brown rounded-periphery shell (for the Mount Kinabalu population) and uniform black animal.   
 Description: Shell (Fig. 6E): large, rather thin, reddish brown, or brown. Spire moderately elevated, outer whorls shouldered below the suture. Periphery angular to round. Above the periphery, shell silky with very weak (but distinct) oblique wrinkling, slightly stronger towards the suture. Amongst this wrinkling, very fine granulation (40¥ magn.) is arranged obliquely. Below the periphery, shell has fine, densely placed spiral grooves. Height up to 12.0 mm; width up to 22.0 mm; diameter of the first three whorls 1.0–1.1, 0.8–0.9, and 1.4–1.6 mm, respectively; number of whorls up to five and oneeighth; height aperture up to 9.3 mm; width aperture up to 11.6 mm. Genitalia (Fig. 7E): maximum length from genital opening to the end of dart-sac (before the visible gland tubules) up to 13 mm. The penis, dart-sac, and vagina very thin with thick muscular walls. P, V, GO, BC, and DS arranged around the short genital atrium, with limited space between the opening of each of the genital structures. Short BC about one-quarter to one-third of total DS length. Animal (Fig. 4D): animal head uniform black and this coloration extends backward to the end of the mantle and downward to the foot-fringe. Grey smear on other parts of animal extending to the end of the tail. The mantle is covered by brown irregular markings and followed by regularly spaced radial dark bands at the last half whorl.   
 Distribution and habitat: Primary lower montane forest. Sabah: Crocker Range (Ulu Kimanis = 1400– 1800 m alt. and Mount Kinabalu = 1400–1900 m alt.) and Upper Padas River (old record) (Figs 5B, 9D).   
 Remarks: The type locality is Upper Padas, north Borneo, but the exact elevation and location is unknown. All the recent material was found at Upper Kimanis and Mount Kinabalu between 1400 and 1900 m, which is at least 70 km in a direct line north-east from the type locality.
description: Published as part of 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, pp. 515-550 in Zoological Journal of the Linnean Society 157 (3) on pages 526-531, DOI: 10.1111/j.1096-3642.2009.00526.x, http://zenodo.org/record/5443023