A cybertaxonomic revision of the micro-landsnail genus Plectostoma Adam (Mollusca, Caenogastropoda, Diplommatinidae), from Peninsular Malaysia, Sumatra and Indochina
Author
Liew, Thor-Seng
Author
Vermeulen, Jaap Jan
Author
Marzuki, Mohammad Effendi bin
Author
Schilthuizen, Menno
text
ZooKeys
2014
393
1
107
http://dx.doi.org/10.3897/zookeys.393.6717
journal article
http://dx.doi.org/10.3897/zookeys.393.6717
1313-2970-393-1
5B035E76BBD14A44A5D8C2140E6168F1
5B035E76BBD14A44A5D8C2140E6168F1
Plectostoma dindingensis
sp. n.
Figure 19, Appendix 7
Type material.
Holotype: BOR 5642(1). Paratypes: BOR 5612(3)
Diagnosis.
Shares with
Plectostoma mengaburensis
and
Plectostoma panhai
the general shell form, in terms of apex, spire and tuba, but differs by lacking constriction teeth and having a more tightly coiled tuba (less than 1/4 of the tuba visible in top view).
Etymology.
This species is named after its type
locality-Dinding
.
Description.
Apex. Shape: moderately convex.
Spire. Height: 1.8-1.9 mm. Width: 1.4-1.5 mm. Number of whorls: 3 7/8-4 5/8. Apical spire shape: depressed conical. Basal spire shape: ovoid. Whorl periphery: distinctly convex. Umbilicus: partially closed by tuba.
Constriction
. Parietal teeth: none. Basal teeth: none.
Tuba. Coiling direction: type 1 and aperture visible from back view. Tuba whorl length in proportion to spire last whorl: ca. 5/8-3/4. Proportion of tuba that attaches to the spire: whole.
Aperture and peristome. Peristome: double peristomes. Outer peristome shape: same as inner peristome and uniformly projected all around, except the posterior part.
Spiral lines. Thick lines: present. Thin lines: present.
Radial ribs. Rib density: 6-8 ribs per mm. Rib intensity: thin. Shape: straight. Inclination: orthoclin.
Figures 19.
Plectostoma dindingensis
sp. n. BOR 5642, Holotype. A frontal view B left lateral view C back view D right lateral view E top view F bottom view G parietal part of constriction inner whorl H basal part of constriction inner whorl. Scale bar = 1 mm (for
A-F
).
Distribution.
Type locality. The exact location is unknown. The specimens are labeled as collected from
"dinding"
. It could be near Kampung Bukit Dinding, Pahang (
3°49'41"N
,
102°22'3"E
).
Distribution range. The species has only been recorded from the type locality (Figure 18D).
Conservation status.
Vulnerable (D2 ver. 10.1). The samples was collected from a living population in 1997. The population status remains unclear. The area around Kampung Bukit Dinding has been converted to plantation and no significant undisturbed forest coverage remains.
Discussion.
See discussion under
Plectostoma christae
.