Gulella hadroglossa Herbert 2016, sp. nov.
Creators: name: Herbert, David G.
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Stylommatophora
Streptaxidae
Gulella
Gulella hadroglossa

description: Gulella hadroglossa sp. nov.
urn:lsid:zoobank.org:act: B0429B6A-4C92-40BB-B2E7-A707A32ADE96
Fig. 3
Etymology
From hadros (Gr.) ‘well-developed, great, strong’, and glossa (Gr.) ‘tongue’; referring to the large, tongue-like parietal lamella.
Material examined
Holotype
SOUTH AFRICA: Mpumalanga, Mariepskop Forest Reserve, Picnic Trail, 24.56847° S, 30.85920° E, 1545 m, northern mist-belt forest, in leaf-litter, D. Herbert, L. Davis & M. Cole, stn 14-27, 4 Dec. 2014, height 3.0 mm, diameter 1.5 mm (NMSA P0230/T4084, dry specimen).
Paratypes
SOUTH AFRICA: Mpumalanga, same data as holotype (NMSA P 0417/T4085, five dry specimens; NHMUK 20160038, one dry specimen; RMNH. 5004142, one dry specimen); Mariepskop Forest Reserve, 24.55117° S, 30.89395° E, 1460 m, indigenous Afromontane forest, in leaf-litter on forest floor, J.L. Horn, 23 Apr. 2005 (NMSA W3500/T4081, four dry specimens); Mariepskop Forest Reserve, Bushpig Trail, 24.56795° S, 30.86138° E, 1520 m, northern mist-belt forest, in leaf-litter, D. Herbert, L. Davis & M. Cole, stn 14-22a, 3 Dec. 2014 (NMSA P0263/T4082, one dry specimen); Mariepskop Forest Reserve, east facing slope, 24.57108° S, 30.86014° E, 1519 m, leg. M. Cole, 18 Oct. 2010 (ELM D16635/T033, three dry specimens); Mariepskop Forest Reserve, in forest beside road at 1520–1700 m, leg. M. Cole, 3–4 Dec. 2014 (ELM D18019/T034, six dry specimens).
Type locality
SOUTH AFRICA: Mpumalanga, Mariepskop Forest Reserve, Picnic Trail, 24.56847° S, 30.85920° E, 1545 m.
Identification
A small species of Gulella with a smooth, glossy, pupiform shell and 3-fold apertural dentition including a very large, oblique, tongue-like parietal lamella projecting far beyond the peristome; a mid-labral plate, the upper edge of which forms a narrow ridge-like tooth that runs obliquely inward and downward; a horizontal in-running tooth at columella base.
Description
SHELL (Fig. 3). Small, pupiform; adult height 3.0– 3.1 mm, diameter 1.45–1.55 mm; H:D 1.96–2.09, with up to 7.25 whorls. Protoconch diameter ~ 0.7 mm, comprising 1.5–1.75 whorls beyond nucleus, smooth and glossy when fresh; junction with teleoconch indistinct. Teleoconch comprising 5.0–5.5 whorls; whorls weakly convex, lacking a shoulder and suture weakly indented (may appear somewhat channelled in eroded specimens); smooth and glossy, sculptured only by occasional weak growthlines, some specimens with faint traces of subsutural pliculae (not evident in holotype); growth-lines stronger and more close-set on apertural tube behind peristome. Aperture ovate, but truncated where peristome interrupted in parietal region; aperture rim flaring and strongly recurved, forming a nearly closed channel behind lip; apertural dentition 3-fold (Fig. 3 C–D): 1) a very large parietal lamella with a tongue-like anterior element that curves outward and to the right, well beyond plane of aperture and then backward towards outer lip; interval between lamella and outer lip partially filled with an overarching shelf, leaving a U-shaped notch behind lamella; 2) a mid-labral plate running inward from a low thickening of outer lip, its upper margin raised to form a narrow ridge that runs obliquely inward and downward (hidden by parietal lamella in frontal view), basal margin usually ill-defined; 3) a narrow in-running tooth near base of columella; a columella lamella is not evident, though in some specimens a very deep-set vertical ledge may be discerned where apertural tube kinks around to join rounded portion of last whorl. A juvenile specimen of ~2.25 teleoconch whorls possessed 4-fold apertural dentition (Fig. 3 F–G) comprising: two well-developed, flattened, semi-circular teeth set transversely at left and right of basal lip, that on the right more deep-set; a curved parietal tooth just beyond limit of aperture, behind and to the right of which arises a fourth, more rounded tooth; a second, identical set of teeth visible by transparency one half-whorl behind aperture. Umbilicus closed, base grooved beneath basal columella tooth (Fig. 3E). Empty shells translucent greyish-white when fresh; yellow colour of dried body showing through in live-collected material.
LIVING ANIMAL. No preserved specimens available.
Distribution
A narrow-range endemic, currently recorded only from Mariepskop Forest Reserve on the edge of the Drakensberg Escarpment in northern Mpumalanga, South Africa; at altitudes from 1460 to 1545 m.
Habitat
Northern mist-belt forest (Mucina & Rutherford 2006), in leaf-litter.
Remarks
Gulella hadroglossa sp. nov. is rendered distinctive amongst small, smooth-shelled Gulella species on account of its large recurved parietal lamella. It is comparable in size (slightly smaller) and superficially similar to G. verdcourti Bruggen, 1966, from the neighbouring Wolkberg massif, but that species has a distinct subsutural shoulder resulting in an incised suture, and its apertural dentition is also different, the parietal lamella not projecting as far and the mid-labral tooth being stronger.
description: Published as part of Herbert, David G., 2016, New narrow-range endemic land snails from the sky islands of northern South Africa (Gastropoda: Streptaxidae and Urocyclidae), pp. 1-29 in European Journal of Taxonomy 236 on pages 7-9, DOI: 10.5852/ejt.2016.236, http://zenodo.org/record/3847840