Alycaeus conformis Fulton, 1902

Foon, Junn Kitt & Liew, Thor-Seng, 2017, A review of the land snail genus Alycaeus (Gastropoda, Alycaeidae) in Peninsular Malaysia, ZooKeys 692, pp. 1-81 : 19-20

Alycaeus conformis Fulton, 1902 Figures 7E, 14, 31D

Alycaeus conformis Fulton, 1902: 68-69; Sykes 1903: 198; Laidlaw 1928: 34; Laidlaw 1932: 36; Venmans 1956: 81, figure 1; Robertson et al. 1987: 2; Chan 1997: 37; Tarruella and Domènech 2011: 72; Páll-Gergely et al. 2016: 20160151; Foon et al. 2017: 10, figure 4B.

Alycaeus confirmis [sic]: Maassen 2001: 21.

Alycaeus coniformis [sic]: Tarruella and Domènech 2011: 72, figure. 1B.

Type locality.

Perak.

Type material.

Syntypes. Perak: ANSP 84690/2 (Seen), NHMUK 1902.5.28.22-23/2 (Seen).

Other examined materials.

KTN 01 Gunung Reng, Kelantan: BOR/MOL 6836/2. KTN 66 Batu Tongkat, Kelantan: ZRC 1975.2.21.88/1. Lojing, Kelantan: BOR/MOL 6526/1. PHG 03 Gunung Jebak Puyuh, Pahang: BOR/MOL 6884/1. PHG 01 Kota Gelanggi, Pahang: BOR/MOL 6887/1, BOR/MOL 8396/2. Mykarst-122 Bukit Merah, Pahang: BOR/MOL 12986/1. PHG 02 Gunung Senyum, Pahang: BOR/MOL 12987/1. PHG 05 Bukit Cintamanis, Pahang: BOR/MOL 6893/1, BOR/MOL 8403/2, BOR/MOL 8404/2. PHG 72 Bukit Panching, Pahang: ANSP 439103/1. Perak: ZRC 1975.2.21.86/1, RMNH 153478/2. PRK 23 Gunung Rapat, Perak: BOR/MOL 10057/1. SGR 02 Bukit Takun, Selangor: BOR/MOL 6809/1, BOR/MOL 8316/2. SGR 01 Batu Caves, Selangor: ZRC 1975.2.21.87/1, ZRC 1990.10274-10288/14. Endau-Kluang, Johor: BOR/MOL 6458/1, BOR/MOL 6459/1.

Description.

Protoconch. Smooth at first whorl, becomes grooved in the second whorl. Grooves arranged parallel to each other and tilted anteriorly at 45° to the coiling axis.

Shell shape. Conical. Shell height: 8.77-10.19 mm. Shell width: 7.16-8.19 mm.

Spire. Spire height: 2.37-3.21 mm. Spire width: 3.24-3.66 mm. Number of whorls: up to 4 ⅜. Spire shape: oblong conical. Whorl periphery rounded. Umbilicus open.

Whorl constriction. At about 4 ¼ whorls posterior of protoconch.

Breathing tube. Length: 4.70-5.76 mm.

Aperture and peristome. Aperture circular, moderately expanded. Aperture height: 4.11-5.14 mm. Aperture width: 4.27-4.93 mm. Peristome double, thickened, slightly notched at suture. Interspace narrow. Peristome orientation 10-16° oblique with respect to the coiling axis.

Spiral lines. Indistinct, regularly spaced. Approximately 11-59 lines per 1 mm.

Radial ribs running anterior of breathing tube. Radial ribs pronounced, evenly spaced. Approximately 10-17 ribs per 1 mm.

Radial ribs running perpendicular to breathing tube. Radial ribs more pronounced and thicker than those anterior of breathing tube, evenly spaced. Approximately 9-13 ribs per 1 mm.

Radial ribs running posterior of breathing tube. Ribs absent. Only radial growth lines.

Operculum. Concave, conical. Exterior covered by thick calcareous layer. Exterior has radially spiral lamellae of 6 revolutions. Interior covered by proteinaceous layer, mamillated.

Shell colour. First 3 whorls usually red or pink. All colours fade to white towards ultimate whorl.

Living animal. Body grey. Head grey. Tentacles dark grey to black.

Habitat and ecology.

Lives under large rotten logs and on leaf litter. In wet, shady forests in both limestone and non-limestone areas.

Distribution. Localised in Perak but widespread in Kelantan, Pahang, Selangor and Johor. Elsewhere, in Phuket, southern Thailand ( Páll-Gergely et al. 2016).

Differential diagnosis Alycaeus conformis is most similar to Alycaeus gibbosulus in shell shape but differs in having a less expanded penultimate whorl, finer radial ribs anterior of breathing tube, shorter constriction whorl, shorter breathing tube, less oblique peristome and multilamellated operculum exterior. The animal body is dark grey in A. conformis compared to brown in A. gibbosulus .

Discussion.

Fulton (1902) stated the type locality of A. conformis as Perak without further specifying the location. Perak is a large state in western Peninsular Malaysia. During recent intensive sampling across limestone hills in Perak, Alycaeus conformis was only discovered at one locality, Gunung Rapat. Alycaeus conformis has also been reported from Kelantan ( Sykes 1903, Laidlaw 1928), Selangor ( Laidlaw 1932, Venmans 1956), Pahang and Johor. Venmans (1956) described the radular morphology of A. conformis from Batu Caves, Selangor. Páll-Gergely et al. (2016) described the microstructures associated with the breathing tube of A. conformis from Phuket Island, Thailand. The shells of A. conformis are often coated in a layer of organic matter when alive (Figure 5E).