Seven new narrowly endemic species of Gulella Pfeiffer, 1856 from eastern South Africa (Gastropoda, Streptaxidae) and status revision for another

. Seven new species of very small Gulella Pfeiffer, 1856 are described from two regions in the interior of south-eastern South Africa within the Maputaland-Pondoland-Albany biodiversity hotspot. In addition, the status of Gulella darglensis benthodon van Bruggen, 1980 is revised and raised to species level. All species are very small-shelled and are narrow-range endemics. Six species, G. judithmastersae sp. nov., G. kevincolei sp. nov., G. hlathikhulu sp. nov., G. nkandla sp. nov., G. mystica sp. nov. and G. libertas sp. nov. are each known from only one locality. The first two as well as G. benthodon and G. mcmasteri sp. nov. are found only in the Amathole Mountains, where poaching, illegal harvesting of plant products and uncontrolled access of cattle take place, including in protected areas. The other four species each occur at one locality in north-central KwaZulu-Natal. The localities of three of the last-mentioned species are in protected areas although they are isolated and surrounded by a heavily transformed cultural landscape rendering enforcement of conservation legislation a challenge. Six species occur in nature reserves, highlighting the importance of small pockets of protected habitat for the conservation of terrestrial snails.


Introduction
Gulella Pfeiffer, 1856 is the most common and diverse genus of Streptaxidae Gray, 1860 in South Africa (Herbert & Kilburn 2004) with 148 species recorded from the country (Cole 2022) while a host of potentially new species have been earmarked for description.Twenty-three species have been described in the past 20 years (Herbert 2002(Herbert , 2006(Herbert , 2016;;van Bruggen 2004van Bruggen , 2006;;Bursey & Herbert 2004;Cole & Herbert 2009, 2022).These recently described and potentially new species were probably overlooked in the past due to their rarity and very limited geographic ranges; the majority are also of very small size.Seven new species of Gulella from south-eastern South Africa are described herein as part of an ongoing effort to document this unrecorded diversity.All species are very small-shelled, and are narrow-range endemics; six are each known from only one locality.After formal description, these taxa will be assessed according to the IUCN Red List to evaluate whether they qualify for threatened status.
This paper focuses on species occurring in two regions of south-eastern South Africa, within the Maputaland-Pondoland-Albany biodiversity hotspot (Steenkamp et al. 2004), namely the Amathole region and north-central KwaZulu-Natal (Fig. 1).All species occur in true forest and are grounddwelling, in leaf-litter or under logs and rocks.
Early records of snails from the Amatholes date to near the beginning of the 1900s and two specimens of Gulella benthodon were collected in about 1920 by Rev. Robert Godfrey (1872-1948).All the other material from the Amatholes examined in this paper was collected in the past 20 years during ongoing focussed surveys to document the snail diversity of the Amathole Mountains and surrounds.At present, there is reasonable knowledge of diversity and distributions, although identifying some taxa to species level is challenging.Approx.55 species of indigenous terrestrial snails have been recorded in the forests of the Amathole region; approximately 14 taxa are endemic to the Amatholes or a portion of the region, including those described herein.
The species described below from north-central KwaZulu-Natal occur in three isolated forests and all the specimens were collected within the past twenty years as part of a programme of field work targeting poorly-surveyed regions of South Africa.Nkandla Forest is known for endemism of molluscs (Herbert & Kilburn 2004;Herbert 2020) and invertebrates in other taxa (Hamer & Slotow 2000;Huber 2003).Hlathikhulu Forest lies between 550 m and 650 m above sea level, near the southern limit of the Lebombo Mountains, at the western margin of the low-lying Maputaland coastal plain.The Vryheid area lies within a molluscan biogeographic subregion founded on the basis of the occurrence of endemic species (Herbert & Kilburn 2004).

Material and methods
The material studied was derived primarily from the collections at the KwaZulu-Natal Museum and the East London Museum.Live-collected samples were dried or obtained in a dry state from leaf-litter samples.In one species an additional specimen was preserved in 99% ethanol as a tissue sample for ongoing molecular studies, and is housed in the KwaZulu-Natal Museum tissue collection.This was not examined.
Shells were photographed using a Zeiss Axio Zoom V16 dissecting microscope with an Axiocam 506 digital camera or a Zeiss Discovery V12 dissecting microscope with an Axiocam 305 digital camera.Stacked images were then combined using Helicon Focus Pro (Helicon Soft Ltd) to provide extended depth of field.For SEM study specimens were coated with gold and examined at an accelerating voltage of 15kV, using a Jeol Neoscope JCM-7000 Benchtop SEM.
Shell length and width measurements were made with the shell held in apertural view and the long axis horizontal.Holotypes were measured with the Line function of the Graphics menu available in the ZEN ver.2.3 pro Hardware used with the Zeiss Discovery V12 dissecting microscope and rounded off to two decimal places.Other specimens were measured using an eyepiece graticule.Shell length: width ratios were calculated and the number of protoconch and teleoconch whorls were counted.The sizing guide of Herbert & Kilburn (2004) was followed.
All records listed as type material are dry shells, either collected alive and kept as shells with dried body parts or collected as dead empty shells still in good condition.Paratypes were distributed among five museums, two in South Africa and three in Europe.Shells in poor condition are listed under 'Other material'.

Diagnosis
Shell very small, cylindrical; sculptured with strong axial ribs; apertural dentition eight-fold, including a strong in-running parietal lamella, a large mid-labral complex with a ridge-like upper margin running into aperture with a tooth near lip edge and another further into aperture, and a larger tooth on its lower margin further from lip edge, a low, inset transverse basal tooth to right of centre, an in-running ridgelike basal tooth to left of centre and a large inset bicuspid columella lamella with two ridge-like teeth; umbilicus widely open.
Type material (not examined)

Description
Shell (Fig. 2).Shell very small, cylindrical, length 3.0-3.6mm, width 1.3-1.5 mm, L:W 2.18-2.49(n = 10).Protoconch approx.0.9 mm in diameter, comprising approx.2.5 whorls, smooth; junction between protoconch and teleoconch distinct.Teleoconch comprising nearly four whorls; first two whorls moderately convex, subsequent two more weakly so; whorls with faint subsutural angle delimiting narrow subsutural ramp; sculptured by well-developed axial ribs, extending from suture to suture (approx.30 on penultimate whorl); rib intervals lacking sculpture (Fig. 2A-B).Aperture sub-quadrate with rounded base and shallowly indented outer lip; dentition eight-fold (Fig. 2C): 1) an oblique, inrunning parietal lamella; 2-4) a large mid-labral complex itself with three teeth, its upper margin ridgelike and running into aperture with a tooth near lip edge and another further into aperture, and a larger rounded tooth on its lower margin set back from lip edge; 5) a low, inset transverse basal tooth to right of centre; 6) an in-running ridge-like basal tooth just to left of centre; 7-8) a large inset columella lamella set with two strong ridge-like teeth (there may also be a smaller bump below these, but it is not always obvious).Labral and basal teeth correspond with deep pits behind outer lip.Umbilicus widely open, elongate-oval, with a deep indentation underlying columella lamella (Fig. 2D).Shell almost transparent when fresh, orange-red coloration of dried tissue of animal visible internally.Distribution (Fig. 3) Endemic to the Amathole Mountains; at altitudes between 1000 m and 1100 m above sea level.

Remarks
We treat Gulella benthodon as a separate species and not as a subspecies of G. darglensis (Melvill & Ponsonby, 1908) as originally proposed.It bears very little resemblance to the other two subspecies of G. darglensis recognised by van Bruggen (1980).It has a large mid-labral complex with three cusps and not a pair of in-running ridge-like labral teeth.The columella lamella also has two strong ridge-like teeth, but both are inset, while in G. darglensis the lower tooth extends almost to the lip edge.The deeply situated columellar teeth were also noted by van Bruggen (1980) and were the origin of the subspecific name.Gulella benthodon has stronger and coarser sculpture than both subspecies of G. darglensis; G. d. darglensis (Melvill & Ponsonby, 1908) has close-set axial riblets and G. d. illovoensis (Burnup, 1914) is smooth.

Conservation
Gulella benthodon is a narrow-range endemic found only in the Amathole Mountains where, despite fairly extensive collecting efforts throughout the mountain range, it has only been found at three localities.Van Bruggen's (1980) specimens came from the Pirie Forest near King Williams Town, collected in about 1920.Recently collected specimens are known only from Hogsback and the majority were collected in the Auckland Nature Reserve.In spite of these being protected sites, poaching and illegal harvesting of plant products takes place and there is uncontrolled access of cattle.

Remarks
Gulella judithmastersae sp.nov.resembles Gulella dejae Bursey &Herbert, 2004 from coastal Eastern Cape andG. viae Burnup, 1925 from Afromontane forests in KwaZulu-Natal and northwards into Mpumalanga and Limpopo provinces.These three species have a very large parietal lamella with oblique outer portion, a trigonal labral tooth running into the aperture, a concave columella lip with a tooth or thickening at the upper and lower ends and an inflated, collar-like apertural tube behind the columella lip.There are differences in the dimensions of the apertural teeth between the three species.The parietal lamella of G. judithmastersae is larger than that of G. dejae; the outer portion projects outwards, but not as prominently as in G. viae.In side view the outer lip arches forward in the vicinity of the labral tooth in G. judithmastersae and even more strongly in G. viae.The labral slab of G. dejae is largest and hence the aperture is more constricted by teeth.Gulella viae has a more pointed tooth on the upper margin of the labral slab.In G. judithmastersae there is a deep-set, oblique in-running ridge-like basal tooth to left of centre at the base of the columella lip, while G. dejae and G. viae have a tooth at the lower end of columella lip in this position, but it does not run into the aperture.Gulella judithmastersae is similar to G. dejae, G. phyllisae Burnup, 1925, G. hamerae Bursey &Herbert, 2004 andG. claustralis Connolly, 1939 in the possession of spiral threads on the protoconch, absent in G. viae.Gulella judithmastersae also bears resemblance to G. arnoldi (Sturany, 1898), but that species also lacks spiral sculpture on the protoconch.Gulella judithmastersae differs from G. phyllisae and G. arnoldi in the large size of the parietal lamella, the position of the basal tooth (to the left not right of centre) and the shape of the columella lamella.Gulella judithmastersae does not resemble G. hamerae or G. claustralis in the shape of the aperture and its dentition.The aperture of the latter two species is y-shaped and the columella lip is indented.

Conservation
Despite fairly extensive collecting efforts throughout the Amathole mountain range, Gulella judithmastersae sp.nov.has been found at only two localities, both in the Isidenge area.It therefore appears to be a very narrow-range endemic.Isidenge is a State Forest protected under the National Forest Act (Act 84 of 1998).

Description
Shell (Fig. 6).Shell minute, sub-cylindrical, length 2.5-3.0 mm, width 1.2-1.5 mm, L:W 1.98-2.15(n = 6).Protoconch approx.0. 9 mm in diameter, comprising approx.2.5 whorls, smooth; junction with teleoconch distinct.Teleoconch comprising approx.4.5 whorls; whorls convex; sculptured with well-developed axial ribs from suture to suture (approx.32 on penultimate whorl; rib intervals lacking sculpture (Fig. 6A-B).Aperture narrowing towards base on right (in apertural view); peristome thickened and reflected; base flattened rather than rounded, dentition four-fold (Fig. 6C): 1) an almost vertical parietal lamella, concave on side facing labral sinus, 2) a large roundly triangular labral slab, somewhat bicuspid in some specimens, leaving only a narrow slit between it and parietal lamella, 3) a ridge-like basal tooth in centre of base, 4) a large, deep-set, elongate columella lamella; in addition, in some specimens the thickened columella may bear a low, broad denticle near its parietal insertion and another near its base, but in other specimens these are scarcely evident.Labral tooth corresponds with a deep pit behind outer lip (Fig. 6B); basal tooth corresponds with a pit behind basal lip.Apertural tube behind columella lip collar-like with fine close-set riblets.Umbilicus widely open, elongate-oval, approx.0.12 mm in length (Fig. 6D).Shell almost transparent when fresh, yellow-orange coloration of dried tissue of animal visible internally.Distribution (Fig. 3) Known only from Hogsback in the Amathole Mountains; at altitudes between 1000 m and 1100 m above sea level.

Remarks
Gulella kevincolei sp.nov.resembles the variable species Gulella farquhari (Melvill & Ponsonby, 1895) but the following differences appear to be consistent.The sculpture of G. kevincolei is much stronger than that of G. farquhari which has variable sculpture, usually in the form of milling just below the suture or weak axial ribbing.Gulella kevincolei has a larger, ridge-like basal tooth which reaches the aperture margin, distinct from the inset basal tooth of G. farquhari.The umbilicus of G. kevincolei is widely open and it has a large, smooth protoconch (0.9 mm in the holotype) clearly distinct from the teleoconch.

Conservation
Gulella kevincolei sp.nov.has been found at only one locality, Hogsback, in the Amathole Mountains, despite fairly extensive collecting efforts throughout the mountain range.It therefore appears to be a very narrow-range endemic, restricted to the main Hogsback forest block.

Description
Shell (Fig. 7).Shell very small to minute, elongate-cylindrical, length 2.4 -2.7 mm, width 1.0-1.2mm, L:W 2.07-2.42(n = 12).Protoconch approx.0. 8 mm in diameter, comprising approx.2.25-2.5 whorls, smooth (Fig. 7A-B); junction with teleoconch not distinct.Teleoconch comprising approx.3.75 whorls; the first convex, but subsequent ones more flat-sided; sculptured by well-developed, but not strong axial ribs, extending from suture to suture (approx.42 on penultimate whorl), weak on early part of first whorl; rib intervals lacking obvious microsculpture (Fig. 7A-B).Aperture somewhat asymmetrical due to narrowing from labral tooth towards base, rounded at base; peristome broadly interrupted in parietal region, middle region of labrum projecting outward in side-view (Fig. 7B).Dentition eight-fold (Fig. 7C): 1) a strong parietal lamella, outer portion oblique and projecting beyond aperture in side-view, extending to level of upper labral tooth, curves and runs into aperture so that side facing labral sinus is concave; 2-4) a strong mid-labral base beginning at lip edge with three labral teeth, one on lip edge (a low bulge), and two further into aperture, lower one stronger; 5) a very low, inset transverse basal tooth to right of centre; 6) a basal tooth to left of centre usually near lip edge; 7) a low, broad tooth on mid to upper columellar lip; 8) a very large, deep-set, rounded columella lamella with thickened distal rim.Labral tooth corresponds with a pit behind outer lip (Fig. 7B).Umbilicus closed (Fig. 7D).Shell almost transparent when fresh, reddish-orange dried tissue of animal visible internally.Distribution (Fig. 3) Recorded from isolated forest patches on the Windvogelberg south of Cathcart, and the Qacu forests north-east of Stutterheim, Eastern Cape; at altitudes between 1200 m and 1500 m above sea level.These forests lie between the Amatholes and the Kei River valley and are disjunct from the large forest blocks of the Amathole Mountains.

Remarks
Amongst other Eastern Cape species of Gulella, the apertural dentition of G. mcmasteri sp.nov.resembles that of G. ponsonbyi (Burnup, 1914), G. caryatis (Melvill & Ponsonby, 1898) and G. phragma (Melvill & Ponsonby, 1907) , but G. mcmasteri has three labral teeth, its basal tooth to the left of centre is close to the lip edge and its columella lamella is differently shaped, resulting in a closed umbilicus.The aperture rim is less thickened than that of G. ponsonbyi, the parietal lamella is smaller and the columella lamella is not mammillate as in G. ponsonbyi, but is concave with a raised edge.Gulella caryatis is more elongate and its axial ribs are weaker, extending only half-way down each whorl and the aperture of G. mcmasteri is markedly more obstructed by teeth.Gulella phragma is a poorly known species also recorded from the Cathcart area, but it is larger (length 4.3 mm) and has a prominent superficial tooth on the columella lip mirrored by the underlying columella lamella, and joined to it by a ridge.

Conservation
Gulella mcmasteri sp.nov. is found in relict forest patches including two formally protected areas, Cathcart Nature Reserve and Qacu Forest Nature Reserve, although this status does not always guarantee protection due to lack of compliance.Cathcart Nature Reserve is on the outskirts of the town with uncontrolled access to people and cattle.Qacu is probably relatively undisturbed due to its isolation.The present landowners of the two private farms on which the species has been recorded are both conservationists and its forest habitats at these localities are therefore safe at present.

Description
Shell (Fig. 8).Shell minute, cylindrical, length 2.7-3.3 mm, width 1.2-1.4mm, L:W 2.03-2.36(n = 7).Protoconch approx.1.0 mm in diameter, comprising approx.2.5 whorls, smooth (Fig. 8A-B); junction between protoconch and teleoconch not distinct.Teleoconch comprising approx.4.25 whorls; first whorl convex, others weakly so, suture not strongly indented; smooth and glossy with a few axial pleats behind labrum and around base (Fig. 8A-B).Peristome little thickened, interrupted in parietal region.Aperture quadrate, base flattened rather than rounded; apertural dentition five-fold (Fig. 8C): 1) a large parietal lamella which curves and runs into aperture; side facing labral sinus concave; 2) a simple labral tooth in the form of an in-running ridge beginning at lip edge; 3) a low, broad, somewhat oblique basal tooth slightly to left of centre beginning very near lip edge; 4) a prominent swelling on columella lip; 5) a large, convex columella lamella with no bulb or swelling.Labral tooth corresponds with a very shallow pit behind outer lip.When viewed from laterally, profile of aperture juts out in position of teeth on labral and columella lips, which lie opposite each other (Fig. 8B).Umbilicus closed (Fig. 8D).Shell translucent when fresh, orange coloration of dried tissue of animal visible internally.

Conservation
Gulella hlathikhulu sp.nov.appears to be a very rare species, with few records.The Hlathikhulu Forest Reserve (also known as the Gwaliweni Forest) is a formally protected area under the jurisdiction of Ezemvelo-KZN Wildlife, the provincial conservation authority for KwaZulu-Natal, although lack of compliance may limit the effectiveness of protected status.The forest habitat crosses the Eswatini [Swaziland] border and probably also occurs further north along the Lebombo Mountains, straddling this international boundary, especially in the surrounds of the Ingwavuma Gorge (Mucina et al. 2018).It is thus possible that G. hlathikhulu occurs at additional, as yet unsampled, sites along this ridge of mountains.

Diagnosis
Shell very small, sub-cylindrical; smooth and glossy; aperture markedly constricted by teeth and narrower towards base; apertural dentition four-fold, including an oblique parietal lamella, a large rounded labral tooth, its outer face concave and its upper margin sinuous, bearing a small cusp near lip edge, an inset tooth in centre of base and a large elongate inset columella lamella; apertural tube behind columella lip somewhat expanded and collar-like; umbilicus very small with distinct peri-umbilical pleats.

Etymology
Named for the type locality, the Nkandla Forest Reserve, KwaZulu-Natal.

Habitat
Patches of KwaZulu-Natal Scarp forest of the KwaZulu-Natal Inland Scarp subtype (Mucina et al. 2018); in leaf-litter and under logs.

Remarks
Gulella nkandla sp.nov.resembles the variable G. farquhari (Melvill & Ponsonby, 1895), but the latter has some form of axial sculpture while G. nkandla is smooth and glossy with axial pleats only on the last whorl behind the labrum and around the umbilicus.Furthermore, the labral tooth of G. nkandla has a definite cusp on its upper margin near the lip edge, lacking in G. farquhari and the columella lamella is more elongate.The labral tooth of G. nkandla bears some resemblance to that of G. contraria Connolly, 1932, in particular the upper denticle, but in the latter species the bulk of the tooth is in the form of an inset ridge that extends inward and basally from the upper denticle, behind the more superficial labral ridge.Gulella contraria also has a very strong, broad, squarish tooth in the middle of the columella lip.

Conservation
Gulella nkandla sp.nov.has been found only at Nkandla Forest Reserve, a protected area under the jurisdiction of the provincial conservation authority, Ezemvelo-KZN Wildlife.

Diagnosis
Shell very small, sub-cylindrical; sculptured with axial ribs extending from suture to suture with spiral microsculpture between them; apertural dentition eight-fold, including a parietal lamella running into the aperture with a sinuous lower margin bearing a notch, a low sinular denticle, a large triangular labral tooth with a peg-like tooth at its upper limit, a low, deeply inset transverse basal tooth to right of centre, a deeply inset trigonal basal tooth to left of centre and a large inset columella lamella consisting of a vertical slab with two ridge-like teeth, pointing obliquely downwards, in its lower half; apertural tube collar-like behind columella lip, umbilicus very small.

Etymology
From the Greek 'mystikos' ('μυστικός'): 'a mystery, mysterious'; with reference to the environs of Nkandla -long considered a region of mystery in Zulu folklore.

Description
Shell (Fig. 11).Shell very small, sub-cylindrical to squat, length 3.2-3.3mm, width 1.7-1.8mm, L:W 1.88-2.00(n = 4).Protoconch approx.0.8 mm in diameter, comprising approx.2.5 whorls, smooth; junction between protoconch and teleoconch distinct.Teleoconch comprising approx.5.5 convex whorls; sculptured with well-developed axial ribs, extending from suture to suture, prosocline on spire whorls and almost orthocline on last whorl, rib intervals with spiral microsculpture (Fig. 11A-B).Aperture sub-quadrate with rounded base; outer lip shallowly indented, columella straight (in aperture view); peristome thickened and reflected; dentition eight-fold (Fig. 11C): 1) an almost vertical parietal lamella, its lower margin sinuous and notched, 2) a minute sinular denticle, 3-4) a large triangular labral tooth extending into aperture, with a small peg-like tooth at its upper limit near lip edge, 5) a deeply inset low, transverse basal tooth to right of centre, 6) a deeply inset pointed trigonal tooth to left of centre, 7-8) a large deeply inset columella lamella consisting of a truncate vertical slab set with two ridge-like downward-pointing teeth in lower half, upper one larger.Aperture indented in region of labral teeth and with a deep pit behind outer lip corresponding to labral tooth base (Fig. 11B).Apertural tube behind columella lip collar-like; umbilicus very small, elongate-ovate, approx.0.08 mm in length (Fig. 11D).Shell almost transparent when fresh, yellow-orange coloration of dried tissue of animal visible internally.Distribution (Fig. 9) Known only from Nkandla Forest Reserve, in northern KwaZulu-Natal; between 1000 m and 1200 m above sea level.

Habitat
Patches of KwaZulu-Natal Scarp forest of the KwaZulu-Natal Inland Scarp subtype (Mucina et al. 2018); in leaf-litter and under logs.

Remarks
Gulella mystica sp.nov.does not bear close resemblance to any other species.The truncate columella lamella with downward-pointing ridge-like teeth at its lower end is unique.Its apertural dentition bears superficial resemblance to certain features of G. mfongosiensis Burnup, 1925 andG. perissodonta (Sturany, 1898), namely the large labral tooth with a small tooth on its upper base, basal teeth to right and left of centre and the columella lamella with two ridges.Both G. mfongosiensis and G. perissodonta have an additional parietal denticle and the former also has a denticle in the middle of the columella lip.Gulella mystica occurs in the same broad vicinity as these other two species (inland in northern KwaZulu-Natal), but they occur in drier bushveld habitats while G. mystica occurs in tall, moist forest.

Conservation
Gulella mystica sp.nov.has been found only at Nkandla Forest Reserve, a protected area under the jurisdiction of Ezemvelo-KZN Wildlife.

Diagnosis
Shell minute, sub-cylindrical; sculptured with weak widely-spaced axial ribs; dentition seven-fold, including an angular parietal lamella, a large, bicuspid labral tooth, the lower cusp stronger, a low, deeply inset transverse basal tooth slightly to right of centre, an in-running tooth at base of columella lip, a prominent tooth in middle of columella lip and a large, convex columella lamella; peristome protruding at position of labral and superficial columella teeth; umbilicus widely open, more or less circular.

Etymology
From Latin 'libertas' meaning 'freedom'.The type locality is in the town Vryheid, Afrikaans for freedom, an area with a history of battles.

Description
Shell (Fig. 12).Shell minute, sub-cylindrical, length 2.2-2.7 mm, width 1.1-1.2mm, L:W 2.03-2.29 (n = 6).Protoconch approx.0.7 mm in diameter, comprising 2.25 whorls, smooth (Fig. 12A-B); junction between protoconch and teleoconch distinct.Teleoconch comprising approx.5 whorls; first whorl convex, others weakly so; first 0.25 whorl with fine, closely spaced riblets, remainder with widely-spaced axial ribs, strong below suture and fading out before reaching next suture except on body whorl (Fig. 12A-B).Peristome very thick and reflected.Aperture more or less quadrate, base rounded; apertural dentition seven-fold (Fig. 12C): 1) an angular parietal lamella, with an oblique ridge extending from angle to middle of parietal region, almost forming a buttress, side of lamella facing labral sinus concave, running into aperture medial to angle, 2-3) two labral teeth fused to form a large plate, the lower tooth stronger, 4) a low, inset transverse basal tooth slightly to right of centre, 5) an in-running, ridge-like basal tooth well to left of centre beginning at base of columella lip, 6) a prominent tooth in middle of columella lip and 7) a large, broadly rounded columella lamella.A weak ridge appears to join the tooth on columella lip and columella lamella in some specimens.Labral tooth corresponds with a deep pit behind outer lip (Fig. 12B).When viewed from either side, profile of aperture juts out in position of teeth on labrum and columella lip, which lie opposite each other.Umbilicus widely open, more or less circular, approx.0.12 mm in diameter (Fig. 12D).Tooth in middle of columella lip corresponds with an elongated pit behind columella lip which joins the umbilicus (Fig. 12D).Shell translucent when fresh, red-orange coloration of dried tissue of animal visible internally.

Remarks
Gulella libertas sp.nov.resembles Gulella melvilli (Burnup, 1914), an uncommon species widely distributed in the interior of KwaZulu-Natal.The major differences are that the axial ribs of G. libertas are stronger, rendering the subsutural region crenulate, and there is a prominent tooth in the middle of the columella lip.Gulella sylvia (Melvill & Ponsonby, 1903) from the Eastern Cape has similar apertural dentition, but it is smooth and has a bicuspid columella lamella.

Conservation
Gulella libertas sp.nov.appears to be a very rare species, known only from the type locality, which is not within a formally protected area.A local, municipal nature reserve, Vryheid Hill Nature Reserve, is nearby and it is likely that the species also occurs there.

Discussion
The Amathole Mountain Range (approx.2000 m a.s.l.) is part of the Great Escarpment of South Africa, an outlier of the southern end of the Drakensberg, isolated by the valleys of the Great Fish and Great Kei Rivers (Stuckenberg 1962).Grassland is by far the dominant biome (82%) while the Forest biome comprises 3% of the area (Clark et al. 2014).The forest type is classified as Southern Mistbelt (Mucina & Geldenhuys 2006) and occurs mainly in valleys and on slopes.The Amathole forest complex is the second largest forested area in South Africa and contains large, more-or-less continuous blocks and smaller, isolated patches.
The species described herein augment the numbers of Streptaxidae and the number of molluscs endemic to the Amathole region (14 taxa).In total, eight species of Gulella have been recorded from the Amatholes, five of which are endemic: Gulella benthodon, Gulella fordycei Cole & Herbert, 2022 and the three new species Gulella kevincolei sp.nov., Gulella judithmastersae sp.nov.and Gulella mcmasteri sp.nov.These species and the majority of endemic molluscs are narrow-range endemics found only in a section of the Amatholes and not throughout.The nearly-endemic Chondrocyclus amathole Cole, 2019 andEuonyma cacuminata (Melvill &Ponsonby, 1892) occur throughout the Amatholes, in the forest patches extending eastwards (where G. mcmasteri occurs) and in the Fort Fordyce-Katberg forests in the west.
The forests in the Amathole region contain flora and fauna of Afromontane affinity, such as the clausiliid Macroptychia africana (Melvill & Ponsonby, 1899).Some of the taxa are of recent origin and migration between coastal areas and the Amatholes has been suggested (Hughes et al. 2005;Herbert & Moussalli 2010).The Great Fish River basin has been identified as an area of persistence of thicket during the contractions of the Last Glacial Maximum (Potts et al. 2012) and thus a possible migration corridor.Chondrocyclus amathole is common throughout the Amatholes and a small population occurs near the mouth of the Great Fish River and in a small forest patch situated between there and the Amatholes (Cole 2019).Palaeo-ecological reconstruction from 12 500 BP until recent times, suggests that the current vegetation assemblage has remained much the same over most of that time.Montane forest occupied greater areas in the mid-Holocene but was still confined to patches which were probably reduced in size by more recent human activity and greater fire frequency (Meadows & Meadows 1988).
The three forests in KwaZulu-Natal, Nkandla, Hlathikhulu and Vryheid differ in composition of vegetation and therefore in forest classification: KwaZulu-Natal Inland Scarp, Northern/Lebombo Scarp and Northern Afrotemperate respectively.Scarp forests are a forest type occurring on south-and east-facing hills and gorges of the first plateau escarpment inland of the coast (300-1100 m) and have ancient evolutionary links to Afrotemperate and tropical forests (Eeley et al. 1999;Hughes et al. 2005;Mucina & Geldenhuys 2006;Lawes et al. 2007;Mucina et al. 2018).There is evidence that lineages in KwaZulu-Natal Scarp forests persisted in refugia during cycles of forest contraction and the surviving relict lineages expanded and radiated as forest cover increased (Griswold 1985;Eeley et al. 1999;Lawes et al. 2007;Tolley et al. 2008;Tilbury & Tolley 2009;Herbert & Moussalli 2010).Endemism in these highly fragmented forests is remarkable and they contain many examples in unrelated taxa of species with extremely narrow distributions (Hamer & Slotow 2000;Huber 2003;Herbert & Kilburn 2004;Hamer 2009;Otte & Armstrong 2017;Mucina et al. 2018;Cole 2019;Herbert 2020) The conservation value of KZN scarp forests is very high as they are isolated and surrounded by a heavily transformed cultural landscape (Mucina et al. 2018).The forests mentioned above are all protected areas under the management of the provincial conservation authority, Ezemvelo-KZN Wildlife.Nkandla Nature Reserve, at 4022 ha, is relatively large and is a complex of seven adjacent nature reserves amalgamated in 2019 (Provincial Notice 1 of 2019).Hlathikhulu is 1213 ha, while Entumeni and Dlinza are only 546 ha and 319 ha respectively.This highlights the importance of very small patches of scarp forest for conserving endemic species.
The forest near Vryheid where Gulella libertas sp.nov.occurs is further from the sea than the scarp forests and is a fragment of Northern Afrotemperate forest (Mucina & Geldenhuys 2006) within a grassland region.A small group of molluscs with restricted ranges occurs in the environs of Vryheid and Ithala Nature Reserve and some of these species extend into Swaziland and Mpumalanga province (Herbert & Kilburn 2004).Gulella libertas is known only from one site, but since the region is not wellcollected, its distribution may prove to be wider.
After formal description, these taxa will be assessed to evaluate whether they qualify for threatened status according to the IUCN Red List or as species of conservation concern in South Africa.The IUCN system does not highlight species that may be at low risk of extinction, but may be of high conservation importance such as range-restricted endemic species and therefore an amended system of categories is used in South Africa (see http://speciesstatus.sanbi.org/about).The majority of species treated here occur in designated protected areas and therefore may not meet the criteria to be listed in one of the categories of threat on the IUCN Red List even though management of some of these areas is very poor.Gulella judithmastersae sp.nov.and G. libertas sp.nov.do not occur in designated protected areas and have an extremely small extent of occurrence (EOO) and area of occupancy (AOO), so these species may qualify as globally threatened.The other species occur in one or very few locations and would be categorized as Critically Rare or Rare species of conservation importance using the South African system.This emphasises the importance of protected areas for the conservation of South African land snails (Cole & Herbert 2022).

Fig. 1 .
Fig. 1.Map of South Africa showing the location of the two regions within the Maputaland-Pondoland-Albany biodiversity hotspot (shaded).
of base, and a large inset elongate columella lamella; the columella lip is also thickened, and has an indistinct swelling at either end in some specimens; umbilicus widely open.
EtymologyNamed for the late Cameron McMaster who had a keen interest in natural history and whose brother, Nigel, farms at the type locality.