Shell dextral or sinistral, constriction easily visible to reduced, umbilicus always closed; protoconch usually with a pitted microsculpture; aperture shifted right or left of shell axis; no pleats visible in the aperture, columella reinforced by 1–2 plates situated right or left of the columella, often with a palatal callosity in opposition, parietalis can be present, often reduced; operculum corneous, multispiral, flat, with an elongate internal apophysis.

Martens (1864: 119) defined the genus Diancta by “penultimate whorl with a constriction”. Quadras and Möllendorff (1895) added the new subgenus Paradiancta (type species Diancta philippinica Quadras & Möllendorff, 1895, from the Philippines), which is characterised by dextral shells with a long palatalis and columellaris. Kobelt (1902: 419) added to the general definition that the shell of Diancta is oval and somewhat irregularly coiled. This short summary shows that the definition of these genera is based on taxonomically unimportant shell characters. Constriction of the shell is not an autapomorphic but a plesiomorphic character; for example, it is found in other genera like Opisthostoma Blanford, 1860 (Vermeulen 1991: 140) and Diplommatina Benson, 1849 (Vermeulen 1993, 1996: 116).

The diplommatinid species of Lord Howe Island were also placed in Diancta by Stanisic et al. (2010). The shells of these species show some resemblance to those from Fiji, and may be closely related to the Fiji radiation. An analysis of the inner lamellar system of these species would be desirable.

Diplommatina martensi var. macrostoma Mousson: lectotype, here designated, ZMZ 526691a, paralectotypes ZMZ 526691/5, Ovalau, coll. Mousson ex Graeffe 1866. — macrostoma Möllendorff: lectotype designated by Zilch (1953: 18) SMF 104905/1, Fiji [“in insula Vitilevu”], coll. Möllendorff ex Mousson.

When establishing Diancta macrostoma as a new species, Möllendorff cited “Diplommatina macrostoma Mouss. ms.”, apparently unaware that Mousson had already described it as Diplommatina martensi var. macrostoma. The two names are homonyms but, as they are not based on the same name-bearing types, they are not objective synonyms.

Shell sinistral, elongate, sculpture of widely spaced ribs, ribbing pattern constant throughout teleoconch.

Shell sinistral, elongate oval, yellowish; last whorl constricted; protoconch broad, obtuse, with a fine pattern of granules; umbilicus closed, concave narrow periomphalum; teleoconch sculpture of coarse widely spaced ribs, ribbing pattern constant throughout the shell, somewhat denser on the dorsal side of penultimate whorl; aperture broadly subquadrate, peristome doubled, with the upper left edge slightly protruding; apertural rims connected by a thin, slightly detaching callus; aperture only just attached to the last whorl; no pleats visible in the aperture; inside the shell, two small columellar plates present.

Operculum corneous, flat, internally with a small lamella.

Lectotype (Fig. 2): H = 2.86; D = 1.93; PH = 1.4; PD = 1.35; W = 5.

Figures 2–4. 

Diancta macrostoma (Mousson, 1870). 2 Lectotype ZMZ 526691 Fiji, Ovalau, H = 2.84 mm 3 paratype, last whorl opened to show internal lamellae (enlarged, not to scale) 4 operculum 4a inner surface 4b outer surface. Figure 1 ×10, Figure 3 ×40 magnification.

(not shown on map). Ovalau Island.

Mousson also recorded this species from Viti Levu. The re-investigation of his specimens revealed that none of them is conspecific with the lectotype of D. macrostoma. For revised identification of these specimens, see Tab. 2.

Possible syntype NHMUK 1867.3.22.4 [said to be from Australia, Lord Howe (error)].

Fiji, Viti Levu, mouth of cave near Suva Bay, coll. Bryant Walker ex Ponsonby, UMMZ 88697 (Solem 1959 as Palaina distorta); Viti Levu, surroundings of Qauia village, secondary wet forest, 20–50 m, -18.0999 178.3999, leg. Bouchet & Warén, 15.03.1999, MNHN/394, NMBE 516879/25; Viti Levu, surroundings of Laselevu village, 80 m, rainforest, -17.7532 178.1416, leg. Bouchet, Warén & Dayrat, 14.02.1999, MNHN/92, NMBE 516880/10. — Tonga, Tongatabu, coll. Bryant Walker ex Ponsonby, UMMZ 87919.

Shell medium sized, sinistral, last whorl strongly constricted, last whorl strongly ascending, apertural rims connected by a large polished callus, axial palatalis.

Shell medium sized, sinistral, elongate oval, yellowish to whitish; last whorl strongly constricted; protoconch large, 1–1.5 whorls, bulbous obtuse, pitted; umbilicus closed, periomphalum narrow; teleoconch sculpture of widely spaced ribs on the initial and the central whorls, ribs becoming coarser and more widespread on the last third of the last whorl; last whorl strongly ascending; aperture quadrate, peristome connected to the last whorl; apertural rims connected by a large polished callus; aperture with a slightly enlarged process over the left edge; no pleats visible in the aperture; inside the shell, columellar plate split into two plates of equal size, with a small but strong axial palatal fold opposite.

Operculum corneous, flat, internally with a small lamella.

Possible syntype (Fig. 5): H = 3.2; D = 2.57; PH = 1.51; PD = 1.48; W = 5.

Figures 5–10. 

Diancta martensi (H. Adams, 1866). 5 Possible syntype NHMUK 1867.3.22.4, err.: “Australia, Lord Howe”, H = 3.2 mm 6 UMMZ 88697 Fiji, Viti Levu, mouth of cave near Suva Bay, coll. Bryant Walker ex Ponsonby 7 UMMZ 87919 Tonga, Tongatabu, coll. Bryant Walker ex Ponsonby 8 Fiji, Viti Levu, Qauia village, 20–50 m, H = 2.62 mm 9 last whorl opened to show internal lamellae (enlarged, not to scale). 10 operculum 10a inner surface 10b outer surface. All figures ×10, Figure 10 ×40 magnification.

(Fig. 170). Recorded from Fiji, Viti Levu, and Tonga, Tongatabu by Solem (1959: 191).

The possible syntype matches well the figure of Adams (pl. 38, fig. 11). The museum’s label records Lord Howe Island as origin, but there is no locality given in the original description. However, the possible syntype does not match the illustrations of Stanisic et al. (2010) of the Lord Howe Island species of Diancta. Thus, the NHMUK label is incorrect, the provenance of D. martensi remains unknown, and the status of NHMUK 1867.3.22.4 is doubtful (possible syntype). On the other hand, the specimens illustrated here from Fiji and Tonga (Figs 6–10) are almost identical with the possible syntype, which thus might originate from one or other of these island groups.

In their analysis of the Godeffroy sales catalogue, Bieler and Petit (2012: 45) listed “Diplommatina distorta Mousson” as a nomen nudum. To complete the history of this name, the Mousson collection in Zurich has been checked: the lots ZMZ 526698/7 (“Dipl. martensi H. Adams, D. distorta Mss, Viti Levu, Graeff. 68” in Mousson’s handwriting), and ZMZ 526699/2 (“Dipl. distorta. Mss, Viti Levu, Graeffe 68” in Mousson’s handwriting) were examined. It is clear that Mousson intended to separate these specimens under the name “distorta”, but this remained a manuscript name. In fact, both lots contain typical specimens of D. martensi. It is not clear why Solem used “Diplommatina distorta Mousson”, nor why he considered the two taxa as distinct.

We here identify the modern lots recorded above with this species. Although on average, specimens from these lots are somewhat smaller than the possible syntype, no other character justifies their separation.

The holotype (by monotypy) could be found neither in MNHN nor in the Mousson collection in Zurich, the SMF, the collection of Charpentier in Lausanne or the Shuttleworth collection in NMBE. The species was not present in the 1989–1999 material. However, the Mousson collection contains a lot of one specimen, which agrees well with the original description (see below). Because of the need to unambiguously stabilize the taxonomic extension of this nominal species, this specimen (ZMZ 526690a; Fig. 11) is here selected as neotype.

Figures 11–12. 

Diancta quadrata (Mousson, 1870). 11 Neotype ZMZ 526690a, Viti Levu, H = 4.56 mm. 12 Original figure Diplommatina quadrata reproduced from Journal de Conchyliologie, 18: pl. VIII, fig. 1 All figures ×10 magnification.

“T. sinistrorsa, oblique lineatim rimata, ovata, confertim costulato-striata, pallide flavula. Spira convexoconica; summo minuto, obtusulo; sutura vix profunda. Anfr. 5, celeriter accrescentes, convexi; primi laevigati; sequentes striati; tertius subinflatus; penultimus in dorso inflatus, in ventre retractus; ultimus fortiter ascendens, attenuatus, infra utrimque compressiusculus, cervice subangulata. Apert. verticalis, tangentialis, intus anguste elliptica, extus magna, subpatula, oblique et obtuse quadrata. Perist. expansum, vix incrassatum; marginibus lamina breviter solutu junctis, lateralibus super medium anfractus penultimi insertis, hic expansiusculis, antrorsum irregulariter undulatis. — Long, 4,6, diam. 2,9 mill. — Rat. apert. 1 : 1. Viti Levu ex Graeffe, one specimen”.

Shell large, yellowish, teleoconch sculpture with narrowly spaced ribs on the entire shell, last whorl with shallow furrow, aperture quadrate to subrectangular, peristome disconnected from last whorl.

(based on neotype). Shell large, sinistral, oval, yellowish, partly translucent; last whorl only slightly constricted, with a broad and shallow furrow; protoconch large, 1–1.5 whorls, bulbous obtuse, pitted; umbilicus closed, periomphalum narrow; teleoconch sculpture of narrowly spaced ribs on the entire teleoconch; last whorl ascending; aperture quadrate to subrectangular, reinforced by a labial callus, peristome disconnected from the last whorl; apertural rims connected by a large polished callus; aperture with a slightly enlarged process over the left edge; no pleats visible in the aperture; internal lamellar structure not investigated.

Operculum unknown.

Neotype (Fig. 11): H = 4.56; D = 3.53; PH = 2.24; PD = 2.16; W = 6.

Viti Levu, precise locality unknown.

This species is placed here in Diancta, because the neotype shows the typical contraction of the teleoconch, described by Mousson as “anfractus…penultimus in dorso inflatus, in ventre retractus”.

Not in NHMUK.

No specimen available.

(original). “Shell with the penultimate whorl contracted in front, leaving the previous one and lip of the aperture joining regularly costated; lip double; aperture circular and entire. Animal with two tentacles, short and cylindrical, with an active arched motion, as in Helicina. Eyes situated at the base of tentacles inside [Hab. Taviuni, Fiji].”

No specimen is available, but no collecting was done in Taveuni. This taxon was overlooked by Kobelt (1902). The original illustration is of a shell with an aperture shifted to the left of the shell axis, which indicates a generic placement in Diancta rather than Moussonia or Palaina.

Holotype MNHN IM-2000-27412, paratypes MNHN/15 IM-2000-27413, NMBE 516869/3. Type locality: Viti Levu, Wailotua karst, 50–80 m, rainforest, -17.7582 178.4166, leg. Bouchet, 25–27.08.1998.

Latin adjective aureus, -a, -um = golden; with reference to the peculiar colour of fresh shells of this species.

Shell sinistral, yellow, narrow periomphalum, with a few very strong ribs on the last third of the last whorl, internal dentition almost completely reduced.

Shell sinistral, small, of a bright yellow colour; last whorl constricted; protoconch broad, obtuse with a pitted microsculpture; umbilicus closed, very narrow periomphalum; teleoconch sculpture initially of coarse widely spaced ribs, changing to a more dense pattern on the next two whorls, almost smooth on the last whorl (particularly above the aperture), followed by a few very strong ribs on the last third of the last whorl; last whorl slightly ascending; aperture circular, not connected to the last whorl, peristome funnel-shaped, simple; apertural rims connected, with a small parietal shield; no dentition visible in the aperture in frontal view; columellar plate with a narrow internal part, outer part reduced to a basal knob.

Operculum corneous, flat, small apophysis, OD = 0.58.

Holotype (Fig. 13): H = 3.48; D = 2.35; PH = 1.46; PD = 1.38; W = 4.5.

Figures 13–15. 

Diancta aurea sp. n. 13 Holotype MNHN IM-2000-27412, Viti Levu, Wailotua karst H = 3.48 mm 14 paratype, last whorl opened to show internal lamellae (enlarged, not to scale) 15 operculum 15a inner surface 15b outer surface. Figure 13 × 10, Figure 15 ×40 magnification.

(Fig. 170). Only known from the type locality.

Diancta aurea sp. n. differs from three species of similar size by the following character states: D. basiplana sp. n. differs in the remarkable form of its enlarged last whorl, D. subquadrata sp. n. in its much finer ribbing pattern on the teleoconch, and D. aurita sp. n. in its characteristic formation of the apertural process and the deep orange apertural shield.

Holotype MNHN IM-2000-27414, paratypes MNHN/4 IM-2000-27415, NMBE 516868/1. Type locality: Viti Levu, Wailotua karst, near summit Uluitova, 370–390 m, rainforest, -17.7582 178.4166, leg. Bouchet, 28.08.1998.

Latin adjective auritus, -a, -um = with long ears.

Large, sinistral shell, yellowish, aperture with an extraordinarily enlarged process over the left edge, aperture orange red.

Shell large, sinistral, elongate oval, yellowish; last whorl slightly constricted; protoconch large, bulbous obtuse, pitted; umbilicus closed, narrow concave periomphalum; teleoconch sculpture of widely spaced ribs on the initial whorls, turning to a more densely spaced pattern on the central whorls, and becoming slightly coarser on the last third of the last whorl; last whorl slightly ascending; aperture circular, orange red, peristome doubled, not connected to the last whorl; apertural rims connected; aperture with an extraordinarily enlarged process over the left edge; no pleats visible in the aperture; inside the shell columellar plate with a reduced inner part, and a broad outer part.

Operculum corneous, flat, internally with a small lamella.

Holotype (Fig. 16): H = 4.39; D = 2.7; PH = 1.78; PD = 1.79; W = 6.

Figures 16–17. 

Diancta aurita sp. n. 16 Holotype MNHN IM-2000-27414, Viti Levu, Wailotua karst, H = 4.39 mm. 17 paratype, last whorl opened to show internal lamellae (enlarged, not to scale. Figure 16 ×10 magnification.

(Fig. 170). Only known from the type locality.

For a differential diagnosis, refer to D. aurea sp. n. There was no complete operculum available for an illustration or proper measurement.

Holotype MNHN IM-2000-27416, paratypes MNHN/44 IM-2000-27417, NMBE 516870/10. Type locality: Viti Levu, Wailotua karst, 50–80 m, rainforest, -17.7582 178.4166, leg. Bouchet, 25–27.08.1998.

Viti Levu, Nakorosule limestone outcrop, 30 m, degraded forest, -17.7734 178.2517, leg. Bouchet & Dayrat, 16.02.1999, MNHN/180, NMBE 516881/20.

Latin noun basis = base, and adjective planus, -a, -um = flat.

Large sinistral shell, last whorl with a broad bulbous expansion, columellar plate forming a twisted tooth-like lamella, periomphalum flat.

Shell large, sinistral, shell colour dull brown; last whorl slightly constricted; protoconch big, bulbous obtuse with pitted microsculpture; umbilicus slit-like closed, periomphalum narrow, flat; last whorl with a broad bulbous expansion, aperture slightly shifted to the left and ascending, basis of the last whorl compressed; teleoconch sculpture of fine regularly spaced ribs, which become coarser on the last third of the last whorl; aperture almost rectangular, peristome doubled; apertural rims connected and detached from the last whorl, with a broad parietal shield; no pleats visible in the aperture; inside the shell with a columellar plate consisting of a twisted tooth-like lamella.

Operculum corneous, with a small apophysis, OD = 0.63.

Holotype (Fig. 18): H = 3.94; D = 2.81; PH = 1.85; PD = 1.96; W = 5.5.

Figures 18–20. 

Diancta basiplana sp. n. 18 Holotype MNHN IM-2000-27416, Viti Levu, Wailotua karst, H = 3.94 mm. 19 paratype, last whorl opened to show internal lamellae (enlarged, not to scale) 20 operculum 20a inner surface 20b outer surface. Figure 18 ×10, Figure 20 ×40 magnification.

(Fig. 170). Central and eastern part of Viti Levu.

Diancta basiplana sp. n. is unmistakable because of its flat periomphalic base, and its twisted columellar plate.

Holotype MNHN IM-2000-27418, paratypes MNHN/8 IM-2000-27419, NMBE 516874/2. Type locality: Viti Levu, Wailotua karst, 50–80 m, rainforest, -17.7582 178.4166, leg. Bouchet, 25–27.08.1998.

Viti Levu, Waivisa karst, 50–80 m, rainforest, -17.6879 178.4033, leg. Bouchet, 27.08.1998, MNHN/5; Viti Levu, Nakorosule limestone outcrop, 30 m, degraded forest, -17.7734 178.2517, leg. Bouchet & Dayrat, 16.02.1999, MNHN/1; Viti Levu, Saweni karst, 50–60 m, dry forest, -17.9032 177.7983, leg. Bouchet, 22.08.1998, MNHN/1.

Latin adjective controversus, -a, -um = coiling in the opposite direction.

Shell dextral, reddish to pinkish, regularly spaced ribs, last whorl slightly ascending, aperture connected to the last whorl, columellar plate with a strong inner plate, opposite a strong axial palatalis.

Shell dextral, oval, medium sized, reddish to pinkish coloured; last whorl constricted; protoconch broad, obtuse; umbilicus slit-like, concave periomphalum; teleoconch sculpture of regularly spaced fine ribs, ribs become somewhat coarser on the last whorl; last whorl slightly ascending; aperture subrectangular, peristome funnel-shaped, doubled; aperture connected to the last whorl with a slight labial callus; no visible pleats in the aperture; inside, columellar plate with a strong inner plate, outer plate less developed, and a basal knob opposite to the inner plate with a strong axial palatalis.

Operculum corneous, flat, internally with a short apophysis, DO = 0.54.

Holotype (Fig. 21): H = 3.2; D = 2.47; PH = 1.53; PD = 1.55; W = 5.5.

Figures 21–23. 

Diancta controversa sp. n. 21 Holotype MNHN IM-2000-27418, Viti Levu, Wailotua karst, H = 3.2 mm 22 paratype, last whorl opened to show internal lamellae (enlarged, not to scale) 23 operculum 23a inner surface 23b outer surface). Figure 21 ×10, Figure 23 ×40 magnification.

(Fig. 170). Central to eastern Viti Levu.

For a differential diagnosis, refer to Diancta dextra sp. n., the only other dextral species of Diancta species so far known in Fiji. Apart from the coiling direction, Diancta controversa sp. n. resembles D. martensi in its aperture, which is attached to the last whorl. Both share a similar axial palatalis, but the columellar plate in D. martensi is not subdivided in two parts of differing size and shape.

Holotype MNHN IM-2000-27420, paratypes MNHN/283 IM-2000-27421, NMBE 516873/20. Type locality: Viti Levu, Wailotua karst, 50–80 m, rainforest, -17.7582 178.4166, leg. Bouchet, 25–27.08.1998.

Viti Levu, Tuvu karst, 50 m, dry forest, -17.9332 177.7067, leg. Bouchet, 23.08.1998, MNHN/11; Viti Levu, Wailotua, 115 m, -17.7664 178.4117, leg. Bouchet, 25.08.1998, MNHN/18.

Latin adjectives densus, -a, -um = close, and costulatus, -a, -um = ribbed.

Sinistral small shell, narrow periomphalum, fine regularly spaced teleoconch ribs, bipartite columellar plate, two palatal and one parietal lamella.

Shell sinistral, oval, small, brownish; last whorl constricted; protoconch broad, obtuse with a pitted microsculpture; umbilicus closed, concave and narrow periomphalum; teleoconch sculpture of fine regularly spaced ribs, in a dense pattern on the upper whorl, pattern more spacious with more coarse ribs on the last whorl; last whorl strongly ascending; aperture circular, connected to the last whorl, peristome funnel-shaped, simple; apertural rims connected, with a broad parietal shield; no dentition visible in the aperture by frontal view; inside with bipartite columellar plate, external part of the plate reduced to a basal knob, internal part a broad lamella, opposite a palatalis (visible in the aperture of fresh shells as an internal knob), a second palatalis just right above the columellar angle, and a parietal lamella present.

Operculum corneous, flat, internally with a small apophysis, DO = 0.38.

Holotype (Fig. 24): H = 2.33; D = 1.46; PH = 1.14; PD = 1.13; W = 5.5.

Figures 24–26. 

Diancta densecostulata sp. n. 24 Holotype MNHN IM-2000-27420, Viti Levu, Wailotua karst, H = 2.33 mm; 25 paratype, last whorl opened to show internal lamellae (enlarged, not to scale) 26 operculum 26a inner surface 26b outer surface. Figure 24 ×10, Figure 26 ×40 magnification.

(Fig. 170). Two localities quite far apart from each other on Viti Levu.

Diancta densecostulata sp. n. differs from D. macrostoma by its slightly smaller shell, the regular dense pattern of the teleoconch ribs, and the internal dentition.

Holotype MNHN IM-2000-27422. Type locality: Viti Levu, Wailotua karst, 50–80 m, rainforest, -17.7582 178.4166, leg. Bouchet, 25–27.08.1998.

Viti Levu, Saweni karst, 50–60 m, dry forest, -17.9032 177.7983, leg. Bouchet, 22.08.1998, MNHN/1.

Latin adjective dexter, dextra, -um = right.

Shell dextral, quite large, reddish, regularly spaced fine ribs, columellar plate reduced, with a palatalis.

Shell dextral, broadly oval, quite large, reddish; last whorl constricted; protoconch broad, obtuse; umbilicus slit-like, concave periomphalum; teleoconch sculpture of regularly spaced fine ribs, ribs slightly coarser on the last whorl; last whorl strongly ascending; aperture subrectangular, peristome funnel-shaped, simple; aperture connected to the last whorl; no visible pleats in the aperture; inside the shell, columellar plate reduced to an almost invisible callus, one palatalis present.

Operculum not recorded.

Holotype (Fig. 27): H = 3.56; D = 2.9; PH = 1.74; PD = 1.73; W = 5.5.

Figures 27–28. 

Diancta dextra sp. n. 27 Holotype MNHN IM-2000-27422, Viti Levu, Wailotua karst, H = 3.56 mm 28 paratype, last whorl opened to show internal lamellae (enlarged, not to scale). Figure 27 ×10 magnification.

(Fig. 170). Two localities in central and eastern Viti Levu.

Diancta dextra sp. n. differs from the similar D. controversa sp. n. by the more coarse pattern of ribbing, the reduced columellar plate, and the missing palatalis. The two species co-occur in the Wailotua karst.

Holotype MNHN IM-2000-27423 paratypes MNHN/662 IM-2000-27424, NMBE 516878/50. Type locality: Viti Levu, Saweni karst, 50–60 m, dry forest, -17.9032 177.7983, leg. Bouchet, 22.08.1998

Viti Levu, Tuvu karst, 50 m, dry forest, -17.9332 177.7067, 23.08.1998, leg. Bouchet, MNHN/301, NMBE 516882/20; Viti Levu, Qalimare karst, Toga village, 30–130 m, dry forest, -17.9953 177.5768, 21.08.1998, leg. Bouchet, MNHN/120, NMBE 516883/15; Viti Levu, Qalimare karst, East of Natawatawadi, 40 m, dry forest, -17.9816 177.6266, 21.08.1998, leg. Bouchet, MNHN/1.

Latin adjective dilatatus, -a, -um = broadened.

Shell sinistral, large, broad, aperture broad and circular, sculpture of coarse, widely spaced ribs, columellar plate reduced.

Shell sinistral, large, stout and broad, of a dull brown colour; last whorl considerably constricted; protoconch broad, obtuse with a pitted microsculpture; umbilicus closed, very narrow periomphalum; teleoconch sculpture of coarse, widely spaced ribs, with a few stronger ribs on the last third of the last whorl; last whorl ascending; aperture broad and circular, disconnected from the last whorl; peristome funnel-shaped, doubled; apertural rims connected; no dentition visible in the aperture by frontal view; columellar plate reduced, with a narrow basal almost denticle-like callus, no other lamellae present.

Operculum corneous, flat, with a long apophysis, OD = 0.59.

(Fig. 29). H = 3.89; D = 2.48; PH = 1.65; PD = 1.83; W = 6.

Figures 29–31. 

Diancta dilatata sp. n. 29 Holotype MNHN IM-2000-27423, Viti Levu, Saweni karst, 50–60 m, H = 3.89 mm 30 paratype, last whorl opened to show internal lamellae (enlarged, not to scale) 31 operculum 31a inner surface 31b outer surface). Figure 29 ×10, Figure 31 ×40 magnification.

(Fig. 170). Four neighbouring localities in central Viti Levu.

Diancta dilatata sp. n. differs from D. subquadrata sp. n. by its larger aperture and the much coarser ribbing pattern. In D. martensi, the aperture is subquadrate, and the peristome is connected to the penultimate whorl. D. subquadrata sp. n. and D. martensi differ from D. dilatata sp. n. by their well developed columellar plate.

Holotype MNHN IM-2000-27425, paratypes MNHN/112 IM-2000-27426, NMBE 516872/15. Type locality: Viti Levu, surroundings of Qauia village, secondary wet forest, 20–50 m, -18.0999 178.3999, leg. Bouchet & Warén, 15.03.1999.

Viti Levu, Wailotua karst, 50–80 m, rainforest, -17.7582 178.4166, leg. Bouchet, 25–27.08.1998, MNHN/49, NMBE 516884/5; Viti Levu, surroundings of Laselevu village, 80 m, rainforest, -17.7532 178.1416, leg. Bouchet, Warén & Dayrat, 14.02.1999, MNHN/57, NMBE 516885/5; Viti Levu, Waivisa karst, 50–80 m, rainforest, -17.6879 178.4033, leg. P. Bouchet, 27.08.1998, MNHN/33, NMBE 516886/5.

Latin adjective distortus, -a, -um = distorted.

Shell sinistral, very small, teleoconch sculpture of regular fine ribs, last whorl only slightly ascending, aperture circular, detached, internally with strong palatal lamella, columellar plate reduced.

Shell sinistral, very small, elongate, yellowish; last whorl strongly constricted; protoconch broad, obtuse with a pitted microsculpture; umbilicus closed, concave periomphalum; teleoconch sculpture of regularly spaced fine ribs, with an abrupt change on the last whorl with ribs becoming very coarse and widely spaced; last whorl only slightly ascending; aperture circular, detached from the last whorl; peristome funnel-shaped, doubled; no dentition visible in the aperture by frontal view; internally with strong palatal lamella visible through fresh translucent shells, columellar plate reduced to a knob-like basal denticle.

Operculum corneous, flat, with a relatively long apophysis, OD = 0.35.

Holotype (Fig. 32): H = 2.39; D = 1.54; PH = 0.89; PD = 0.91; W = 5.5.

Figures 32–34. 

Diancta distorta sp. n. 32 Holotype MNHN IM-2000-27425, Viti Levu, Qauia village, 20–50 m, H = 2.39 mm 33 paratype, last whorl opened to show internal lamellae (enlarged, not to scale) 34 operculum 34a inner surface 34b outer surface). Figure 32 ×10, Figure 34 ×40 magnification.

(Fig. 170). eastern part of Viti Levu.

Diancta distorta sp. n. differs from all the other small Diancta species by its elongate shell and the unique combination of reduced columellar plate and opposing palatal lamella. In its outer shell morphology it resembles D. densecostulata, but in the latter the aperture is always attached to the penultimate whorl (and differs completely in its inner lamellae).

Holotype MNHN IM-2000-27427, paratypes MNHN/136 IM-2000-27428, NMBE 516875/50. Type locality: Viti Levu, Wailotua karst, 50–80 m, rainforest, -17.7582 178.4166, leg. Bouchet, 25–27.08.1998.

Latin adjective pulchellus, -a, -um = handsome.

Sinistral, large shell, last whorl shifted to the left, periomphalum perspectively broadened, broad basal columellar plate.

Shell large, sinistral, oval, light brown to yellowish; last whorl constricted; protoconch big, bulbous obtuse with microsculpture of minute granules; umbilicus slit-like, closed, periomphalum perspectively broadened; last whorl considerably shifted to the left, only slightly ascending; teleoconch sculpture of fine, regularly spaced ribs, much coarser on the last third of the last whorl and more widely spaced; aperture almost rectangular, peristome doubled; apertural rims connected; aperture shortly detaching from the last whorl with an extraordinarily enlarged ear-like process over the left edge; no pleats visible in the aperture; inside the shell with a single, broad basal columellar plate (Fig. 36, arrows).

Figures 35–37. 

Diancta pulchella sp. n. 35 Holotype MNHN IM-2000-27427, Viti Levu, Wailotua karst, H = 4.56 mm 36 paratype, last whorl opened to show internal lamellae (arrows showing the limits of the columellar plate; enlarged, not to scale) 37 operculum 37a inner surface 37b outer surface. Figure 35 ×10, Figure 37 ×40 magnification.

Operculum corneous, flat, internally with a broad apophysis, DO = 0.75.

Holotype (Fig. 35): H = 4.56; D = 3.59; PH = 1.66; PD = 1.61; W = 5.

(Fig. 170). Only known from the type locality.

Diancta pulchella sp. n. is the largest diplommatinid so far known from Fiji. It cannot be confused with any other Diancta species because of its aperture, which is completely shifted to the left side of the shell. Diancta aurita sp. n. has a similar ear-shaped apertural process, but differs in all other respects including the orange colouration of its aperture. Diancta basiplana sp. n. differs by its bulbous extension on the last whorl, the attached aperture, the ribbing pattern, and the simple peristomial rim.

Holotype MNHN IM-2000-27429, paratypes MNHN/213 IM-2000-27430, NMBE 516876/20. Type locality: Viti Levu, Saweni karst, 50–60 m, dry forest, -17.9032 177.7983, leg. Bouchet, 22.08.1998.

ZMZ 526682c/2, Viti Levu, leg. Graeffe 1872.

Latin adjective rotundus, -a, -um = rounded; with reference to the shape of the aperture.

Shell sinistral, small, whitish, penultimate whorl enlarged, change in ribbing pattern of teleoconch, columellar plate reduced, a small palatal fold.

Shell sinistral, elongate oval, small, whitish to translucent; last whorl strongly constricted; protoconch small, smooth; umbilicus slit-like open to completely closed, periomphalum concave; teleoconch sculpture of coarse spacious ribs on the upper whorl, fine and dense on the medium and coarse and spacious on the last whorl; penultimate whorl enlarged; last whorl slightly ascending; aperture circular, peristome funnel-shaped, doubled; aperture slightly detaching from last whorl; no pleats visible in the aperture; inside the shell, columellar plate reduced, with a small palatal fold opposite.

Operculum corneous, flat, internally with a small lamella, OD = 0.4.

Holotype (Fig. 38): H = 2.65; D = 1.68; PH = 1.07; PD = 1.03; W = 5.5.

Figures 38–40. 

Diancta rotunda sp. n. 38 Holotype MNHN IM-2000-27429, Viti Levu, Saweni karst, H = 2.65 mm. 39 paratype, last whorl opened to show internal lamellae (enlarged, not to scale) 40 operculum 40a inner surface 40b outer surface. Figure 38 × 10, Figure 40 ×40 magnification.

(Fig. 170). Only known from the type locality.

Diancta rotunda sp. n. is one of the smallest species of the genus in Fiji, along with D. distorta sp. n., D. densecostulata sp. n., D. macrostoma, and D. trilamellata sp. n., but it can be distinguished from these by its enlarged penultimate whorl. Its teleoconch sculpture is similar to that in D. trilamellata sp. n., but the latter species possesses a palatalis and parietalis.

Holotype MNHN IM-2000-27431, paratypes MNHN/21 IM-2000-27432, NMBE 516877/5. Type locality: Viti Levu, limestone outcrop SE of Nambukulevu, 230 m, rainforest, -18.1366 177.8149, leg. Bouchet, Warén & Dayrat, 20.02.1999.

Latin prefix sub = somewhat, and adjective quadratus, -a, -um = squared; with reference to the shape of the aperture.

Shell sinistral, broad, small, brownish, ribbing pattern changing from coarse on the upper whorls to fine on the medium and coarse on the last whorl, aperture circular, columellar plate broad.

Shell sinistral, broadly oval, small, brownish; last whorl considerably constricted; protoconch large, 1–1.5 whorls, pitted; umbilicus closed, periomphalum narrowly concave; ribbing pattern on teleoconch of coarse and spacious ribs on the upper whorl, fine and dense on the intermediate whorls, and coarse and widely spaced again on the last whorl; last whorl slightly ascending and detaching from the last whorl; aperture circular, peristome funnel-shaped, doubled, peristomial rims connected by a broad parietal shield; no pleats visible in the aperture; columellar plate broad, not subdivided, no inner lamellae present.

Operculum corneous, flat, with a long apophysis, OD = 0.59.

Holotype (Fig. 41): H = 3.29; D = 2.02; PH = 1.35; PD = 1.55; W = 5.

Figures 41–43. 

Diancta subquadrata sp. n. 41 Holotype MNHN IM-2000-27431, Viti Levu, limestone outcrop SE of Nambukulevu, H = 3.29 mm. 42 paratype, last whorl opened to show internal lamellae (enlarged, not to scale) 43 operculum 43a inner surface 43b outer surface. Figure 41 ×10, Figure 43 ×40 magnification.

Only known from the type locality.

Diancta subquadrata sp. n. is very similar to D. densecostulata, but differs by its broadly expanded peristome, reduced columellar plate, and complete absence of internal lamellae.

Holotype MNHN IM-2000-27433, paratypes MNHN/62 IM-2000-27434, NMBE 516871/10. Type locality: Viti Levu, Waivisa karst, 50–80 m, rainforest, -17.6879 178.4033, leg. Bouchet, 27.08.1998.

Latin numeral tres = three, and adjective lamellatus, -a, -um for possessing lamellae.

Shell sinistral, very small, teleoconch sculpture of coarse ribs, initially widely, then densely, spaced, last whorl ascending, aperture circular, detached from last whorl, with a palatal and a parietal lamella and broad columellar plate.

Shell sinistral, very small, whitish to yellowish; last whorl strongly constricted; protoconch broad, obtuse with a pitted microsculpture; umbilicus closed, very narrow periomphalum; teleoconch sculpture initially of coarse widely spaced ribs, changing to a more dense pattern on the central whorls, with a few very strong ribs on the last whorl; last whorl strongly ascending; aperture almost circular, not connected to the last whorl, peristome doubled and funnel-shaped, apertural rims connected; no dentition visible in the aperture by frontal view; internally with a palatal and a parietal lamella, columellar plate broad, subdivided into an inner and outer part, inner part with a slight notch.

Operculum corneous, flat, with a short apophysis, OD = 0.39.

Holotype (Fig. 44): H = 2.37; D = 1.91; PH = 1.13; PD = 1.17; W = 5.

Figures 44–46. 

Diancta trilamellata sp. n. 44 Holotype MNHN IM-2000-27433, Viti Levu, Waivisa karst, 50–80 m, H = 2.37 mm 45 paratype, last whorl opened to show internal lamellae (enlarged, not to scale) 46 operculum, 46a inner surface, 46b outer surface). Figure 44 ×10, Figure 46 ×40 magnification.

(Fig. 170). only known from the type locality.

Diancta trilamellata sp. n. superficially resembles D. martensi, but differs from it by its smaller size, the detached aperture, and the presence of a parietal lamella.

Shell elongate conical, dextral, oval, almost non-umbilicate; protoconch whorls smooth; teleoconch whorls usually with a blunt keel; whorls completely smooth to finely ribbed, sometimes with fine thread-like spirals; last whorl narrowed; columellaris ends as a tooth-like lamella in a central to basal position in the aperture; internal lamellar system with one columellaris, two parietal lamellae and one to two palatal lamellae. The operculum was not observed.

The Samoan Pupa problematica Mousson, 1865, the type species of Moussonia, is illustrated here for comparison (Fig. 140, Syntype ZMZ 526751, Samoa, Upolu, H = 1.9 mm). Unfortunately, there are not enough specimens of the type species available to document its inner lamellar system.

Lectotype, here designated, ZMZ 526754/a, Fiji, Iles de Lau, Oneata, coll. Mousson ex Graeffe, 1868. — Paralectotypes: ZMZ 526754/20, SMF 105171/2, coll. Möllendorff ex Mousson.

Lau Islands: Aiwa, stunted forest on limestone, 5–20 m, -18.3316 -178.6825, leg. Bouchet, 07.03.1999, MNHN/153, NMBE 516888/15; Yacata (=Yathata), forest on limestone, 5–10 m, -17.2584 -179.5096, leg. Bouchet, 05.03.1999, MNHN/35, NMBE 516889/5; Yagasa Levu, south point of island, forest on limestone, 20–50 m, -18.952 -178.4533, leg. Bouchet, 11.03.1999, MNHN/1174, NMBE 516887/70.

Shell dextral, small, dark brown, teleoconch sculpture of widely spaced ribs with fine periostracal threads, whorls inconspicuously keeled, palatalis short, tooth-like.

Shell dextral, small, last whorl not constricted, translucent light to dark brown; protoconch consisting of 2 whorls, granulated; teleoconch of > 5 whorls with an almost inconspicuous keel, sculpture consisting of faint, widely spaced ribs with fine periostracal threads; suture deep; last whorl slightly ascending before aperture; aperture attached to last whorl, rounded, peristomial rim reinforced by a strong white labial callus, columellar side with a strong columellaris; umbilicus closed; internal lamellar system with one columellaris, two parietal lamellae and one palatalis; columellaris a strong lamella, with a well-developed undulation at its end above the aperture; inner parietalis a long thread-like lamella, outer parietalis large, spatulate; palatalis a short lamella, directly above the aperture (can be seen from the outside as a reflecting callus).

Lectotype (Fig. 47): H = 2.35; D = 0.59; PH = 0.73; PD = 1.39; W = 7.5.

Figures 47–49. 

Moussonia fuscula (Mousson, 1870). 47 Lectotype ZMZ 526754, Fiji, Lau Islands, Oneata, coll. Mousson ex Graeffe 1868, H = 2.35 mm 48 Lau Islands, Yagasa Levu, south point of island, H = 2.19 mm 49 last whorl opened to show internal lamellae. All figures ×20 magnification.

(Fig. 171). several islands of the central Lau group.

Lectotype, here designated, ZMZ 526756/a, Fiji, Ovalau, coll. Mousson ex Graeffe 1868. — Paralectotypes ZMZ 526756/20; ZMZ 526755/6, Viti Levu, coll. Mousson ex Graeffe 1868.

Limestone outcrop SE of Nambukulevu, 230 m, rainforest, -18.1366 177.8149, leg. Bouchet, Warén & Dayrat, 20.02.1999, MNHN/95, NMBE 516890/15; Nakorosule limestone outcrop, 30 m, degraded forest, -17.7734 178.2517, leg. Bouchet & Dayrat, 16.02.1999, MNHN/432, NMBE 516891/40. Lau Islands: Aiwa, stunt forest on limestone, 5-20 m, -18.3316 -178.6825, leg. Bouchet, 07.03.1999, MNHN/124; Lau Islands: Evuevu Island, NW Vanua Balavu, forest on limestone, 5-50 m, -17.0591 -179.0209, leg P. Bouchet, 01.03.1999, MNHN/2.

Shell dextral, medium sized, yellowish to red-brown, bluntly keeled teleoconch whorls, palatalis an elongate undulate lamella.

Shell dextral, medium sized, last whorl slightly constricted, yellowish to red-brown; protoconch of 2 whorls, smooth; teleoconch of > 5 bluntly keeled whorls; sculpture of fine, densely spaced ribs; suture deep; last whorl not or only slightly ascending before aperture; umbilicus almost closed; aperture attached to last whorl, subrectangular, peristomial rim doubled, reinforced by a labial callus, columella with a strong columellaris; internal lamellar system with one columellaris, two parietal lamellae and one palatalis; columellaris a thin lamella, slightly undulating at its end above the aperture, where it is reinforced by a callus; inner parietalis a long lamella, outer parietalis spatulate and oblique; palatalis in a central position above aperture, formed like an undulate lamella and ending in a knob-like tooth visible as a red-brown callus from the outside.

Operculum unknown.

Lectotype (Fig. 50): H = 2.02; D = 1.14; PH = 0.63; PD = 0.65; W = 7.

Figures 50–52. 

Moussonia vitiana (Mousson, 1870). 50 Lectotype ZMZ 526756, Fiji, Ovalau, coll. Mousson ex Graeffe 1868, H = 2.02 mm. 51 Viti Levu, Nakorosule limestone outcrop, 30 m, H = 2.24 mm 52 whorl opened to show internal lamellae. Figures 50–51 ×20, Figure 52 ×40 magnification.

(Fig. 170). Eastern part of Viti Levu and the neighbouring island of Ovalau.

For a differential diagnosis, refer to M. vitianoides sp. n.

Holotype MNHN IM-2000-27435, paratypes MNHN/35 IM-2000-27436, NMBE 516853/5. Type locality: Fiji, Lau Islands, Yacata (= Yathata), forest on limestone, 5–10 m, -17.2584 -179.5096, leg. Bouchet, 05.03.1999.

Lau Islands, Yagasa Levu, south point of island, forest on limestone, 20–50 m, -18.952 -178.4533, leg. Bouchet, 11.03.1999, MNHN/2.

Latin adjective acutus, -a, -um = pointed.

Elongate acute shell, very small aperture, > 8 rounded whorls, both parietal lamellae thread-like, palatalis missing.

Shell dextral, small, elongate turreted, deep reddish brown; protoconch of 2 whorls, smooth; teleoconch of > 8 well rounded whorls, almost smooth, only a few faint, widely spaced riblets; suture deep; last whorl not ascending before aperture; aperture very small, attached to last whorl, obliquely rounded, peristomial rim reinforced by a strong labial callus, columellar side with a strong columellaris; umbilicus slightly open; internal lamellar system with one columellaris, two parietal lamellae and one palatalis; columellaris a thin lamella, without undulation at its end above the aperture; inner parietalis a long thread-like lamella, slightly overlapping with the second low parietalis; palatalis missing.

Operculum unknown.

Holotype (Fig. 53): H = 2.08; D = 0.85; PH = 0.49; PD = 0.51; W = 8.5.

Figures 53–54. 

Moussonia acuta sp. n. 53 Holotype MNHN IM-2000-27435, Fiji, Lau Islands, Yacata (= Yathata), H = 2.08 mm 54 paratype, last whorl opened to show internal lamellae. Figure 53 ×20, Figure 54 ca. ×50 magnification.

(Fig. 171). Two islands in the Lau archipelago.

Moussonia acuta sp. n. is unmistakable because of its very narrow shell form, which is unique among Fiji Diplommatinidae.

Holotype MNHN IM-2000-27437, paratypes MNHN/46 IM-2000-27438, NMBE 516859/10. — Type locality: Viti Levu, surroundings of Qauia village, secondary wet forest, 20–50 m, -18.1001 178.3999, leg. Bouchet & Warén, 15.03.1999.

This species is named after Gary Barker, formerly of Landcare Research, Hamilton, New Zealand, in recognition for his efforts to get the land snails of Fiji onto the local conservation agenda.

Shell minute, dextral, light brown, inner parietalis long, outer parietalis spatulate, palatalis long, directly above the aperture, undulating.

Shell minute, dextral, biconical, last whorl slightly constricted, light brown to yellowish; protoconch consisting of 2 whorls, smooth; teleoconch of > 4 well rounded whorls, sculpture consisting of fine and widely spaced riblets; last whorl only slightly ascending before aperture; aperture attached to last whorl, subquadrate, relatively large, peristomial rim reinforced by a thick white labial callus, columellar side with a strong columellaris; internal lamellar system with one columellaris, two parietal lamellae and one palatalis; columellaris a thin lamella, with a strong undulation at its end above the aperture; inner parietalis a thin lamella, not connected to the second spatulate parietalis; very long palatalis directly above the aperture (can be seen from the outside as a long fine thread), with a central undulation.

Operculum unknown.

Holotype (Fig. 55): H = 1.3; D = 0.66; PH = 0.53; PD = 0.51; W = 5.5.

Figures 55–56. 

Moussonia barkeri sp. n. 56 Holotype MNHN IM-2000-27437, Viti Levu, surroundings of Qauia village, H = 1.3 mm 56 paratype, last whorl opened to show internal lamellae. Figure 55 ×20, Figure 56 ×40 magnification.

(Fig. 170). Only known from the type locality.

Moussonia barkeri sp. n. is unique in its combination of a minute shell with an aperture the size of that of larger species. It differs from the similar sized M. minutissima sp. n. by its more obese shell, its long undulating palatalis, and the larger outer parietalis.

Holotype MNHN IM-2000-27439, paratypes MNHN/33 IM-2000-27440, NMBE 516856/5. Type locality: Lau Islands, Cikobia-i-Lau (= Thikombia), forest on limestone, 10–60 m, -17.2857 -178.7944, leg. Bouchet, 03.03.1999.

This species is named after Giliane Brodie, lecturer at the University of the South Pacific, to acknowledge and encourage her conversion from nudibranch taxonomy to land snail conservation.

Shell dextral, small, translucent light yellow, teleoconch sculpture of strong, widely spaced ribs, aperture rounded, inner parietalis short, outer parietalis low, palatalis short tooth-like.

Shell dextral, small, last whorl slightly constricted, translucent light yellow; protoconch consisting of 2 whorls, smooth; teleoconch of > 5 bluntly keeled whorls, sculpture consisting of strong, widely spaced ribs, which can bear a periostracal bristle at the periphery (only in really fresh shells); suture deep; last whorl slightly ascending before aperture; aperture attached to last whorl, rounded, peristomial rim reinforced by a strong labial callus, columellar side with a strong columellaris; internal lamellar system with one columellaris, two parietal lamellae and one palatalis; columellaris a thin lamella, with a strong undulation at its end above the aperture; inner parietalis a short lamella, overlapping with the outer parietalis, which is a low lamella; very short palatalis directly above the aperture (can be seen from the outside as a small reflecting callus).

Operculum unknown.

Holotype (Fig. 57): H = 1.75; D = 0.95; PH = 0.56; PD = 0.58; W = 6.5.

Figures 57–58. 

Moussonia brodieae sp. n. 57 Holotype MNHN IM-2000-27439, Lau Islands, Cikobia-i-Lau (= Thikombia), H = 1.75 mm 58 paratype, last whorl opened to show internal lamellae. Figure 57 ×20, Figure 58 ×40 magnification.

(Fig. 171). the Lau island Cikobia-i-Lau.

Moussonia brodieae sp. n. is conchologically close to M. polita sp. n., but the latter has only faint ribs, a glossy shell surface, and a very long palatalis, which terminates in a small knob.

Solem (1978) recorded from Mothe Island a shell briefly characterized as “a form with heavy radial sculpture, [...] differing clearly from the smooth-shelled M. fuscula” and that he suspected to probably represent an undescribed species. This may have been M. brodieae sp. n.

Holotype MNHN IM-2000-27441, paratypes MNHN/630 IM-2000-27442, NMBE 516852/50. Type locality: Lau Islands, Navutu-i-Loma (= Nasau), forest on limestone, 5–30 m, -18.9659 -178.4798, leg. Bouchet, 11.03.1999.

Latin adjective longus, -a, -um = long, and noun palatalis for the palatal fold; used as a noun in apposition.

Shell dextral, very small, translucent light yellowish-brownish, bluntly keeled whorls, reduced sculpture, palatalis a very long lamella.

Shell dextral, very small, last whorl not constricted, translucent light yellowish-brownish; protoconch of 2 whorls, granulated; teleoconch of > 7 bluntly keeled whorls, sculpture of faint periostracal threads; suture very deep; last whorl not ascending before aperture; aperture attached to last whorl, rounded, peristomial rim reinforced by a weak labial callus, columellar side with a strong columellaris; umbilicus closed; internal lamellar system with one columellaris, two parietal lamellae and one palatalis; columellaris a thin lamella, with a strong undulation at its end above the aperture; inner parietalis long, outer parietalis spatulate; palatalis a very long lamella, situated on the left side above the aperture (can be seen from the outside as a reflecting callus).

Holotype (Fig. 59): H = 2.13; D = 1.09; PH = 0.65; PD = 0.69; W = 7.5.

Figures 59–60. 

Moussonia longipalatalis sp. n. 59 Holotype MNHN IM-2000-27441, Lau Islands, Yacata (= Yathata), H = 1.68 mm 60 paratype, last whorl opened to show internal lamellae. Figure 59 ×20, Figure 60 ×40 magnification.

(Fig. 171). Only known from the type locality.

Although very similar to M. fuscula, Moussonia longipalatalis sp. n. is treated here as a different species because the latter has a smaller shell, bluntly keeled whorls, and a long and very readily visible palatalis, which is only a short knob-like callus in M. fuscula.

Holotype MNHN IM-2000-27443, paratypes MNHN/169 IM-2000-27444, NMBE 516854/20. Type locality: Lau Islands, Yacata (= Yathata), forest on limestone, 5–10 m, -17.2584 -179.5096, leg. Bouchet, 05.03.1999.

Latin adjective minutissimus, -a, -um = very small.

Shell dextral, small, light brownish, protoconch granulated, ribs with periostracal threads, inner parietalis very short, palatalis tooth-like directly above aperture.

Shell dextral, small, last whorl not constricted, translucent light brownish; protoconch of 2 whorls, granulated; teleoconch of > 5 whorls with an almost inconspicuous keel, sculpture of faint, widely spaced ribs with fine periostracal threads; suture deep; last whorl slightly ascending before aperture; aperture attached to last whorl, rounded, peristomial rim reinforced by a strong labial callus, columellar side with a strong columellaris; umbilicus slightly open; internal lamellar system with one columellaris, two parietal lamellae and one palatalis; columellaris a thin lamella, with a strong undulation at its end above the aperture; inner parietalis a very short thread-like lamella, outer parietalis small, spatulate; palatalis tooth-like, directly above the aperture (can be seen from the outside as a reflecting callus).

Operculum unknown.

Holotype (Fig. 61): H = 1.54; D = 0.85; PH = 0.54; PD = 0.57; W = 5.5.

Figures 61–62. 

Moussonia minutissima sp. n. 61 Holotype MNHN IM-2000-27443, Fiji, Lau Islands, Yacata (=Yathata), H = 1.54 mm 62 paratype, last whorl opened to show internal lamellae. Figure 61 ×20, Figure 62 ×40 magnification.

(Fig. 171). Only known from the type locality.

Moussonia minutissima sp. n. is remarkable because of its granulated protoconch. It differs from M. barkeri sp. n. by its reduced tooth-like palatalis and very short inner parietalis, and from M. fuscula by its smaller size and the short inner parietalis.

Holotype MNHN IM-2000-27445, paratypes MNHN/9 IM-2000-27446, NMBE 516860/2. Type locality: Fiji, Viti Levu, Wailotua karst, 50–80 m, rainforest, -17.7582 178.4166, leg. Bouchet, 25–27.08.1998.

Viti Levu, Wailotua, 115 m, in washings from freshwater seeps, -17.7664 178.4117, leg. Bouchet, 25.08.1998, MNHN/5.

Latin adjective obesus, -a, -um = fat.

Shell dextral, broad, bluntly keeled, with widely spaced ribs, inner parietalis long, outer parietalis spatulate, long palatalis, situated above aperture.

Shell dextral, relatively large and broad, last whorl not constricted, deep red-brownish; protoconch of 2 whorls, smooth; teleoconch of > 5 bluntly keeled whorls, sculpture of strong, densely spaced ribs with a fine sculpture of spiral threads (high magnification needed); suture deep; last whorl slightly ascending before aperture; aperture attached to last whorl, subrectangular, peristomial rim slightly reinforced by a weak labial callus, columellar side with a strong columellaris; internal lamellar system with one columellaris, two parietal lamellae and one palatalis; columellaris a thin lamella, with a strong undulation at its end above the aperture with a small denticle on top of the undulating part; inner parietalis a long lamella, which increases in height towards its end, outer parietalis large, spatulate; palatalis above the aperture forming a long and strong lamella.

Operculum unknown.

Holotype (Fig. 63): H = 2.54; D = 1.46; PH = 0.92; PD = 0.86; W = 6.5.

Figures 63–64. 

Moussonia obesa sp. n. 63 Holotype MNHN IM-2000-27445, Viti Levu, Wailotua karst, H = 2.54 mm 64 paratype, last whorl opened to show internal lamellae. Figure 63 ×20, Figure 64 ×40 magnification.

(Fig. 170). Only known from the type locality.

Moussonia obesa sp. n. is instantly recognized by its broad shell. It differs from the similar M. uncinata sp. n., which has an axial palatalis, situated deep in the shell.

Holotype MNHN IM-2000-27447, paratypes MNHN/49 IM-2000-27448, NMBE 516855/7. Type locality: Lau Islands, Yacata (= Yathata), forest on limestone, 5–10 m, -17.2584 -179.5096, leg. Bouchet, 05.03.1999.

Latin adjective politus, -a, -um = smooth, shining.

Shell dextral, translucent light yellow, glossy shining, almost smooth, inner parietalis thread-like, outer parietalis spatulate, palatalis extremely long ending above the angular edge of the peristome.

Shell dextral, small, last whorl well constricted, translucent light yellow; protoconch of 2 whorls, smooth; teleoconch of > 5 well rounded whorls, sculpture of a few faint, widely spaced ribs, shell glossy shining; suture deep; last whorl slightly ascending before aperture; aperture attached to last whorl, rounded, peristomial rim reinforced by a strong labial callus, columellar side with a strong columellaris; umbilicus slightly open; internal lamellar system with one columellaris, two parietal lamellae and one palatalis; columellaris a thin lamella, with a strong undulation at its end above the aperture; inner parietalis a long thread-like lamella, slightly overlapping with the second spatulate parietalis; palatalis extremely long, directly above the aperture, starting as a lamella besides the columellar side of the aperture, ending above the angular edge of the peristome with a small denticle.

Operculum unknown.

Holotype (Fig. 65): H = 1.64; D = 1.01; PH = 0.57; PD = 0.54; W = 6.

Figures 65–66. 

Moussonia polita sp. n. 65 Holotype MNHN IM-2000-27447, Lau Islands, Yacata (=Yathata), H = 1.64 mm 66 paratype, last whorl opened to show internal lamellae. Figure 65 ×20, Figure 66 ×40 magnification.

(Fig. 171). Yacata (=Yathata) in the Lau Is.

For a differential diagnosis, refer to M. brodieae sp. n.

Holotype MNHN IM-2000-27449, paratypes MNHN/257 IM-2000-27450, NMBE 516858/30. Type locality: Viti Levu, surroundings of Qauia village, secondary wet forest, 20–50 m, -18.1001 178.3999, leg. Bouchet & Warén, 15.03.1999.

Viti Levu, surroundings of Laselevu village, 80 m, rainforest, -17.7532 178.1416, leg. Bouchet, Warén & Dayrat, 14.02.1999, MNHN/13, NMBE 516893/3.

Latin adjective uncinatus, -a, -um = hooked; with reference to the hook-like palatalis of this species.

Shell dextral, deeply red-brown; teleoconch sculpture of fine, widely spaced riblets, suture with deep incision dorsolaterally on the last whorl, inner parietalis inconspicuous, outer parietalis spatulate, palatalis above angular edge of peristome.

Shell dextral, spindle-shaped, last whorl slightly constricted, deeply red-brown; protoconch of 2 whorls, smooth; teleoconch of > 6 slightly shouldered whorls, sculpture of fine, widely spaced riblets; suture deep, with a deep notch dorsolaterally on the last whorl indicating the inner end of the palatalis (see arrows); last whorl slightly ascending before aperture; aperture attached to last whorl, subquadrate, peristomial rim reinforced, doubled, white, columellar side with a strong columellaris; internal lamellar system with one columellaris, two parietal lamellae and one palatalis; columellaris a lamella with a large brown denticle on top of the lamellar area just above the aperture, extending into the interior of the shell, where it abruptly bends upwards; inner parietalis an inconspicuous broad and flat callus, not connected to the outer parietalis, which is a thin, spatulate lamella; palatalis deep inside the shell above the angular edge of the peristome forming a strong, hook-like lamella with a moderately deep corresponding furrow on the outer side of the shell, its inner end indicated by a sutural incision.

Operculum unknown.

Holotype (Fig. 67): H = 2.46; D = 1.29; PH = 0.8; PD = 0.84; W = 7.5.

Figures 67–68. 

Moussonia uncinata sp. n. 67 Holotype MNHN IM-2000-27449, Viti Levu, surroundings of Qauia village, H = 2.43 mm 68 paratype, last whorl opened to show internal lamellae (enlarged). Figure 67 ×20, Figure 68 ×40 magnification.

(Fig. 170). two localities on Viti Levu.

Moussonia uncinata sp. n. can be identified by the hook-like palatalis and the small furrow on the last whorl, indicating its end. It has some similarities with M. obesa sp. n., but the latter has stronger ribs, a palatalis parallel to the suture, and non-spathulate prt2. Among the Fiji Moussonia species, M. uncinata sp. n. is one of the largest. It shares the axial and deeply situated palatalis with M. vitianoides sp. n.; for differences, refer to that species.

Holotype MNHN IM-2000-27451, paratypes MNHN/127 IM-2000-27452, NMBE 516857/20. Type locality: Viti Levu, Nakorosule limestone outcrop, 30 m, degraded forest, -17.7734 178.2517, leg. Bouchet & Dayrat, 16.02.1999.

Fiji, Viti Levu, Waivisa karst, 50 m, in washings from karstic spring, -17.6879 178.4033, leg. Bouchet, 27.08.1998, MNHN/25, NMBE 516904/5; Viti Levu, Waivisa Karst, 50–80 m, rainforest, -17.6879 178.4033, leg. Bouchet, 27.08.1998, MNHN/58, NMBE 516892/7.

Vitiana and suffix -oides, meaning similar to M. vitiana.

Shell dextral, yellow brownish, teleoconch with bluntly keeled whorls, densely spaced ribs, both parietal lamellae simple, two palatal lamellae, first palatalis above aperture, second palatalis above angular edge of peristome.

Shell dextral, small, last whorl almost not constricted, yellow brownish; protoconch of 2 whorls, smooth; teleoconch of > 5 bluntly keeled whorls, sculpture of strong, densely spaced ribs; suture deep; last whorl slightly ascending before aperture; umbilicus, slit-like open; aperture attached to last whorl, subrectangular, peristomial rim doubled, reinforced by a strong labial callus, columellar side with a strong columellaris; internal lamellar system with 1 columellaris, two parietal and two palatal lamellae; columellaris a thin lamella, with a strong undulation at its end above the aperture; inner parietalis a long lamella, which increases in height towards its end, shortly overlapping with the outer parietalis, which is a low lamella; first palatalis a fine elongate lamella above the aperture, the second palatalis deep inside the shell above the angular edge of the peristome forming a strong almost axially orientated lamella running from the palatum to the inner basal surface of the whorl, corresponding to a small sutural furrow on the outer side of the shell.

Operculum unknown.

Holotype (Fig. 69): H = 1.98; D = 1.14; PH = 0.67; PD = 0.68; W = 6.5.

Figures 69–71. 

Moussonia vitianoides sp. n. 69 Holotype MNHN IM-2000-27451, Viti Levu, limestone outcrop SE of Nambukulevu, H = 1.98 mm 70 paratype, last whorl opened to show internal lamellae 71 Fiji, Viti Levu, Waivisa Karst, H = 2.03 mm. Figures 69, 71a ×20, Figures 70, 71b ×40 magnification.

(Fig. 170). Two karstic outcrops in eastern central Viti Levu.

The first palatalis is not present in all specimens. M. vitianoides sp. n. can superficially be confused with M. vitiana. It differs from it by the presence of two palatal lamellae, with the second one in an almost axial position. This remarkable feature can also be observed in M. uncinata sp. n., but the latter has a larger, deep brown shell, and lacks the first palatalis.

Shell elongate oval, last whorl not constricted, usually with a bulbous last whorl, aperture in a rather central position in relation to the shell longitudinal axis, without apertural dentition; internal dentition mainly concerns formation of the columellaris, which may be toothed to completely unarmed; operculum with or without concentric lamellae; with a low arcuate ridge on the inner surface.

Semper established the name Palaina without providing a description. Kobelt’s (1902: 394) definition is undiagnostic, as this author included under this header many species from the Pacific diplommatinid radiation, which can be considered a polyphyletic assemblage: “Shell ovate cone-shaped, in most cases sinistral, with a diverse sculpture. Last whorl constricted at the beginning or the first quarter; aperture without teeth, operculum deeply sunken, uncalcified, circular, with several whorls. Shell elongate oval; no dentition; operculum corneous, with thick concentric ridges” [translated from German].

A re-definition of Palaina was provided by Yamazaki et al. (2013: 16), who considered Eupalaina Kobelt & Moellendorff, 1898 as a subgenus of Palaina (subsequent type designation Palaina patula Crosse, 1866). The type species of Palaina is Diplommatina macgillivrayi Pfeiffer, 1854, from Lord Howe Island, from which island several species of Palaina are recorded (Stanisic et al. 2010). Comparing their shells to those from Palau and to those from Fiji that we include in Palaina, they differ by their quite compact and stout outline (the Fiji species are more variable in shape). The inner lamellar system of the Lord Howe radiation is unknown. However, Tillier (1981) illustrated the operculum of P. macgillivrayi, which seems to have a bilobed ridge on the inner surface, and thus differs from what is seen in the Palau species, which have a single strong ridge (Yamazaki et al. 2013: Figs 10A–D), and in the Fiji species, which have a low, inconspicuous rigde. In shell shape and formation of the opercula, the Fiji “Palaina” are close to those from New Caledonia, but unfortunately, Tillier (1981) did not investigate the internal lamellar system in the latter, so potentially useful information is lacking. The species in the New Caledonia radiation have no penis, while the Palau species possess one. Yamazaki et al. (2013) claimed that Tillier (1981) found P. macgillivrayi to also have no penis, a statement that, however, is not explicit in Tillier’s text. For Fiji, no information is available in this regard at present. This short review shows that knowledge of this group is patchy. It seems possible that all the different island radiations will have to be separated at the generic level once the full set of characters is known. For the time being, we conservatively apply Palaina in a broad sense to the Fiji radiation, although we anticipate a separation at the generic level (for which the name Macropalaina is available) from the Lord Howe and Palau radiations The Fiji species might not even be monophyletic.

The 2 specimens originally mentioned by Mousson could not be traced in the collection of Mousson in Zurich nor in the collection of the Journal de Conchyliologie in Paris. In a lot in ZMZ, however, originally identified by Mousson as “D. martensi”, a specimen similar to the - somewhat sketchy - original illustration of D. ascendens is present. This specimen cannot be considered type material, because it was acquired by Mousson in his collection in 1872, i.e. two years after the description of the species. To stabilize the use of the name, this specimen is here selected as neotype. Neotype: ZMZ 526689d, here designated, Viti Levu, “Tatatan”, coll. Mousson ex Graeffe 1872 (Fig. 72). The locality “Tatatan” could not be identified with certainty; possibly it is Cautata, NE of Suva.

Figures 72–73. 

Palaina ascendens (Mousson, 1870). 72 original figure from Journal de Conchyliologie, 18: pl. VIII, fig. 5: H = 3.8 mm 73 neotype ZMZ 526689d, Viti Levu, “Tatatan”, H = 3.31 mm. All figures ×10 magnification.

“T. sinistrorsa, longe rimata, acute ovata, lamellosocostulata, carneo-albescens. Spira convexo-conica; summo obtusulo, graniformi; sutura subprofunda. Anfr. 5 1/2, celeriter accrescentes, convexi; nucleolares laevigati; sequentes ventrosi, lamelliferi; penultimus in ventre retractus et compressus, tenuiter costulatus, lateraliter ruga transversa proeditus; ultimus attenuatus, lente et valde usque ad suturam anfr. tertii fere ascendens, ad rimam paulo impressus. Apert. tangentialis, sursum versa [40° cum axi], transverse perobliqua, subpatula, intus et extus obtuse quadrata. Perist. subexpansum, antice duplicatim incrassatum; marginibus convergentibus, lamina sinistrorsa junctis; columellari et externo supra antrorsum productis, infra sinuatis. Columella obtuse nodulata, interdum lamina producta circumdata. — Long. 3,8, diam. 2,2 mill. — Rat. anfr. 5: 1. — Rat. apert. 5: 4. Hab. Ile de Viti-Levu.”

Shell whitish, moderately large bulb, sculpture of widely spaced ribs, aperture subquadrate, with two denticles.

Shell sinistral, medium sized, oval, whitish; protoconch acute, granulated; last whorl not constricted with a moderately large bulb; last whorl strongly ascending; teleoconch sculpture of coarse widely spaced ribs; umbilicus slit-like, periomphalum narrow; aperture subquadrate, peristome reinforced by a lip, with two denticles on each side (Fig. 73, arrows), broadly attached to last whorl; no pleats visible in the aperture; internal lamellar system not studied.

Operculum unknown.

Neotype (Fig. 73): H = 3.31; D = 2.13; PH = 1.32; PD = 1.40; W = 5.

Uncertain.

The lot ZMZ 526689 contained a larger number of Diancta martensi (ZMZ 526689c), but also one specimen of P. tuberosa (ZMZ 526689a) and a specimen of P. latecostata (ZMZ 526689b).

Diplommatina ascendens is here classified in Palaina because it has a well-developed bulb. It is unmistakable by the formation of the aperture: usually, species of Palaina have a rounded aperture, and not a subquadrate oblique aperture, which is probably why Mousson may have merged it with the superficially similar Diancta martensi. However, the latter is a true species of Diancta as evidenced by the lack of a bulb and the internal lamellar system.

godeffroyana lectotype, here designated, ZMZ 526678/a, Fiji, Viti Levu, Island of Nagara [probably now Naqara; also spelled Nanggara, south-east of Viti Levu], Graeffe 1868; paralectotypes ZMZ 526678/4; probable paralectotypes SMF 105089/4, Fiji, Viti Levu, coll. Möllendorff ex Mousson. — fracta syntypes: ZMZ 526681/4, Fiji, Viti Levu.

SMF 105091/1, Viti Levu, coll. O. Boettger ex Schlüter 1887; ZMZ 526686a/9, Viti Levu, “Tatatan” [a place name we could not identify], Graeffe 1872; ZMZ 526684/15, Viti Levu, Graeffe 1872; ZMZ 526688/1, Viti Levu, Vaini Loba, Graeffe 1872; ZMZ 526682a, Viti Levu, Graeffe 1872; Viti Levu, Waivisa karst, 50–80 m, rainforest, -17.6879 178.4033, leg. Bouchet, 27.08.1998, MNHN/24, NMBE 516894/5; Viti Levu, Saweni karst, 50–60 m, dry forest, -17.9032 177.7983, leg. Bouchet, 22.08.1998, MNHN/1; Viti Levu, Wailotua karst, 50–80 m, rainforest, -17.7582 178.4166, leg. Bouchet, 25–27.08.1998, MNHN/1.

Shell sinistral, elongate oval, white, bulb reduced, last whorl ascending, lamellar system reduced.

Shell sinistral, elongate oval, white to light yellowish; protoconch acute, granulated, consisting of 2 whorls; last whorl not constricted, bulb reduced, inconspicuous; teleoconch sculpture of widely spaced ribs, ribbing pattern slightly wider on the last two whorls; last whorl strongly ascending; aperture circular, in a central position, broadly adhered to the last whorl, peristomial rims connected; umbilicus closed, periomphalum narrow; lamellar system completely reduced; bulb lamella very weak.

Outer surface with concentric rings of lamellae, internal surface concave and smooth inside, OD = 0.52.

Lectotype godeffroyana (Fig. 74): H = 3.4; D = 1.84; PH = 1.36; PD = 1.29; W = 5.5.

Figures 74–78. 

Palaina godeffroyana (Mousson, 1870). 74 lectotype of Diplommatina godeffroyana ZMZ 526678 Fiji, Viti Levu, Island of Nagara, Graeffe 1868, H = 3.4 mm 75 syntype of Diplommatina godeffroyana var. fracta ZMZ 526681, Viti Levu, H = 3.76 mm 76 Viti Levu, Waivisa karst, 50–80 m, H = 3.14 mm 77 ditto, last whorl opened to show internal lamellae (enlarged, not to scale) 78 ditto, operculum 78a inner surface 78b outer surface. Figures 74–77 ×10, Figure 78 ×40 magnification.

(Fig. 170). Many sites on Viti Levu.

Palaina godeffroyana resembles P. pomatiaeformis, which, however, differs by its larger and elongate shell, denser ribbing pattern, and the presence of a basal columellar denticle.

Lectotype, here designated, ZMZ 526679/a, Fiji, Viti Levu, coll. Mousson ex Graeffe 1868. — Paralectotypes ZMZ 526679/6.

ZMZ 526686b/5, Viti Levu, “Tatatan” [a place name we could not identify], Graeffe 1872; ZMZ 526685/8, Fiji, Island of Ovalau, Graeffe 1866; ZMZ 526682b/7, Viti Levu, Graeffe 1872 [as D. godeffroyana].

Shell sinistral, small, bulb well developed, periomphalum compressed, aperture circular, peristome with a faint labial callus, columella obliquely twisted, bulb lamella present.

Shell sinistral, small, broadly oval, whitish to greenish; protoconch acute, granulated; last whorl not constricted, slightly ascending; bulb well developed; umbilicus closed, periomphalum compressed; sculpture of teleoconch whorls with widely spaced ribs; aperture circular, simple, adhered to the last whorl; peristome with a faint labial callus; oblique view into the aperture revealing a strong columellaris; internally, columella obliquely twisted, forming a horizontal lamella in its lower third; a moderately strong bulb lamella present, in some specimens entering the parietum as a thick lamella; small parietalis present.

Operculum corneous, with a long lamella on the outer surface, internally smooth, OD = 0.55.

Lectotype (Fig. 79): H = 3.2; D = 1.73; PH = 1.35; PD = 1.22; W = 6.5.

Figures 79–81. 

Palaina latecostata (Mousson, 1870). 79 Lectotype ZMZ 526679a, Viti Levu, H = 3.20 mm 80 paralectotype, last whorl opened to show internal lamellae (enlarged, not to scale) 81 operculum 81a inner surface 81b outer surface. Figure 79 ×10, Figure 81 ×40 magnification.

Ovalau and the hitherto mysterious locality “Tatatan” (or Tatatau?) on Viti Levu (possible Cautata, NE of Suva).

Possible syntypes ZMZ 526676/4. This lot contains 4 specimens from two places, as can be seen from the labels: 1. Viti Levu, “Vai Loban” [= Vaini-Loba], Graeffe [18]68 and 2. Viti Levu (S coast) Graeffe [18]72. The specimens from Vaini-Loba, the type locality, are mixed with those from the S coast, which reached Mousson after the description, and are not part of the type series. The Vaini-Loba material cannot be recognized; nonetheless, all specimens are conspecific. — Possible syntypes SMF 105141/2, Fiji, Viti Levu, coll. Möllendorff ex Mousson.

Viti Levu, surroundings of Qauia village, secondary wet forest, 20–50 m, -18.1001 178.3999, leg. Bouchet & Warén, 15.03.1999, MNHN/28, NMBE 516895/7; Viti Levu, surroundings of Laselevu village, 80 m, rainforest, -17.7532 178.1416, leg. Bouchet, Warén & Dayrat, 14.02.1999, MNHN/5.

Shell sinistral, large, elongate spire, light yellowish, widely spaced ribs with occasionally interspersed smaller ribs, central teleoconch whorls rapidly increasing in diameter suture deep, columella with a small knob-like denticle.

Shell sinistral, large, elongate spire, white to light yellowish; protoconch acute, granulated, consisting of 2 whorls; initial teleoconch whorls narrow, subsequent whorls rapidly increasing in diameter; last whorl not constricted, bulb of moderate size; teleoconch sculpture of widely spaced ribs with occasionally interspersed smaller ribs, rib pattern constant throughout the whole shell; deep suture and well-rounded whorls; last whorl ascending; aperture circular, in a central position, broadly adhered to the last whorl, peristomial rims connected; umbilicus closed, periomphalum narrow; internally, columella not reinforced with a small knob-like denticle at the base; bulb lamella very weak.

Outer surface with concentric rings of lamellae, internal surface concave and smooth inside, OD = 0.91.

Possible syntype (Fig. 82): H = 4.8; D = 2.26; PH = 1.53; PD = 1.57; W = 6.

Figures 82–85. 

Palaina pomatiaeformis (Mousson, 1870). 82 Possible syntype ZMZ 526676, Vaini-Loba (?), H = 4.8 mm 83 Viti Levu, surroundings of Qauia village, 20–50 m, H = 5.09 mm 84 ditto, last whorl opened to show internal lamellae (enlarged, not to scale). 85 ditto, operculum 85a inner surface 85b outer surface. Figures 82, 83 ×10, Figure 85 ×40 magnification.

(Fig. 170). several localities on Viti Levu.

This is the type species of Macropalaina. The character states in this species compare very well with those in Palaina as defined here, the only difference being the remarkable lamellate operculum. Until the diagnostic value of the operculum has been investigated there is no reason to separate Macropalaina from Palaina, and they are here treated as synonyms, as did previous authors before us.

Palaina pomatiaeformis is the largest Palaina species so far known from Fiji. It differs from all other Palaina species by its narrow initial teleoconch whorls and the last whorls that rapidly increase in diameter. This characteristic “Cochlostoma-like” feature prompted Möllendorff to separate it in its own genus. However, an acute protoconch with somewhat narrower upper teleoconch whorls can also be found in P. godeffroyana and other species. Size and shell form make P. pomatiaeformis a species that cannot be confused with any other Palaina species.

No type specimens of D. subregularis could be traced in MNHN or in ZMZ. Under the name D. subregularis, the Mousson collection houses the lot ZMZ 526677 which, according to the handwritten label, originates from “Viti Levu, Graeffe 1872”. Although identified by Mousson himself as his D. subregularis, this lot is not type material, because it reached Mousson two years after the description of the taxon, and it does not originate from the type locality. From the same locality “Viti Levu”, four specimens in SMF 105079/4 (coll. Möllendorff ex Mousson, also as D. subregularis), had been identified as “cotypes” by A. Zilch. It is highly probable that these specimens also come from ZMZ 526677, and thus were not originally part of the type series. Moreover, SMF 105079/4 consists of three shells that do match with “subregularis” in the sense of Mousson, and one that does not, but is P. godeffroyana. In order to stabilize the application of this name, we here designate a neotype from ZMZ 526677, because the specimens from this lot match the description of Mousson very well. Neotype: subregularis ZMZ 526677a, Viti Levu, coll. Mousson ex Graeffe 1872 (Fig. 86).

Figures 86–92. 

Palaina subregularis (Mousson, 1870). 86 Neotype ZMZ 526677a, Viti Levu, H = 3.5 mm 86 specimen ex ZMZ 526677, last whorl opened to show internal lamellae (enlarged, not to scale) 88 ditto, operculum 88a inner surface, 88b outer surface) 89 Diplommatina graeffei (Möllendorff, 1897), lectotype SMF 104903 Viti Levu, H = 2.7 mm. 90 Viti Levu, Tuvu karst, H = 3.62 91 ditto, last whorl opened to show internal lamellae (enlarged, not to scale). 92 ditto, operculum, 92a inner surface, 92b outer surface. Figures 86, 89, 90 ×10, Figures 88, 92 ×40 magnification.

D. graeffei: lectotype, designated by Zilch (1953: 17, pl. 6 fig. 89), SMF 104903/1, Fiji, Viti Levu, coll. Möllendorff ex Mousson. The name graeffei had already been used by Mousson in his collection (ZMZ 526702/many, “Dipl. graeffei Mss., Viti Levu (Graeffe)”), but had remained a manuscript name. The lectotype of graeffei matches the shells in this lot so well that the SMF specimen most probably originates from this lot; however, there is no evidence that Möllendorff ever saw the specimens in the Mousson collection when he published the name Diplommatina graeffei, and the specimens in ZMZ 526702 are not regarded by us as paralectotypes.

SMF 105079/4, Fiji, Viti Levu, coll. Möllendorff ex Mousson; Viti Levu, Voli Voli limestone outcrop, 10–30 m, secondary open forest, -17.3374 178.1831, leg. Bouchet, Warén & Dayrat, 18.02.1999, MNHN/8; Viti Levu, limestone outcrop SE of Nambukulevu, 230 m, rainforest, -18.1366 177.8149, leg. Bouchet, Warén & Dayrat, 20.02.1999, MNHN/6; Viti Levu, Qalimare karst, Toga village, 30–130 m, dry forest, -17.9953 177.5768, leg. Bouchet, 21.08.1998, MNHN/255, NMBE 516896/20; Viti Levu, Tuvu karst, 50 m, dry forest, -17.9332 177.7067, leg. Bouchet, 23.08.1998, MNHN/172, NMBE 516897/20.

Shell sinistral, elongate oval, teleoconch whorls with widely spaced ribs, brown axial flames or blotches between the ribs, aperture circular, bulb reduced, columella a broad lamella, basally with columellar tooth.

Shell sinistral, elongate oval, eroded shells purely white, well preserved specimens with a pattern of brown axial flames or blotches between the ribs; protoconch acute, granulated; last whorl not constricted, slightly ascending; bulb reduced, demarcated by a faint bulb lamella; umbilicus closed, periomphalum narrow; sculpture of teleoconch whorls with widely spaced ribs, ribbing pattern above the aperture somewhat denser; aperture circular, sometimes with a double lip demarcated by a brown line, adhered to the last whorl; oblique view into the aperture revealing a strong columellaris; internally, columella forming a broad lamella extending towards the interior of shell, basally forming a columellar tooth.

Operculum corneous, outer surface with several concentric lamellae and a single, short raised lamella; internal surface concave, smooth.

Neotype of subregularis (Fig. 86): H = 3.5; D = 1.71; PH = 1.24; PD = 1.26; W = 7; lectotype of graeffei (Fig. 89): H = 2.7; D = 1.35; PH = 0.99; PD = 0.89; W = 7.

(Fig. 170). Quite widespread on Viti Levu.

After a careful comparison of the lectotype of D. graeffei with the rest of the material attributed to P. subregularis, it was not possible to find any discriminating characters between the two taxa besides shell size, and we conclude that the former is a small specimen of the latter.

For a differential diagnosis, refer to P. flammulata sp. n., P. truncata sp. n., and P. parietalis sp. n.

Lectotype MNHN IM-2000-26707 [number of specimens not originally mentioned; the original specimen deposited in the collection of Journal de Conchyliologie is herewith designated as lectotype].

ZMZ 526687/3, “Viti Levu (Vai-Loba) Südküste”, coll. Mousson ex Graeffe 1872; ZMZ 526689a/1, Viti Levu, “Tatatan”, coll. Mousson ex Graeffe, 1872 [identified by Mousson as “D. martensi”].

Shell sinistral, small, bulb well developed, whorls widely ribbed, area above aperture fine and densely ribbed, labial callus weak, columella obliquely twisted, truncate with a thick bi-lobed tooth, parietalis a long slightly raised lamella.

Shell sinistral, small, broadly oval, faint yellowish; protoconch acute, granulated; last whorl not constricted, slightly ascending; bulb well developed; umbilicus closed, periomphalum narrow; sculpture of teleoconch whorls with widely spaced ribs, area above the aperture with fine and densely arranged ribs; aperture circular, simple, adhered to the last whorl; aperture with a weak labial callus, two small ear-like processes on the upper edges of the peristome; by oblique view into the aperture columellaris visible; internally, columella obliquely twisted, truncate in the lower half forming a thick bi-lobed tooth; parietum with a long slightly raised parietalis in front of the bulb.

Operculum unknown.

Lectotype (Fig. 93): H = 2.93; D = 1.68; PH = 1.11; PD = 1.21; W = 6.

Figures 93–94. 

Palaina tuberosa (Mousson, 1870). 93 Lectotype MNHN IM-2000-26707, Vaini-Loba, south coast of Viti Levu, H = 2.93 mm 94 ZMZ 526687, last whorl opened to show internal lamellae (enlarged, not to scale). Figure 93 ×10 magnification.

Vaini-Loba (or Vai-Loba?) on the southern coast of Viti Levu (modern name not identified); not found during the 1998–99 field work.

Palaina tuberosa can easily be confused with P. tuberosissima sp. n., which is similar in shell size and shape. P. tuberosa differs from it by having the dense ribbing pattern of the area above the aperture, the weak labial callus, and the reduced ear-like processes on the peristome. In the internal lamellar system, P. tuberosa has only a bilobed columellar tooth, its parietalis is not spatulate, and a palatalis and second columellaris are missing altogether.

Holotype ZMZ 526680, paratypes ZMZ 526680/3. Type locality: Viti Levu, Nagar[r]a [probably now Naqara; also spelled Nanggara, south-east of Viti Levu], coll. Mousson ex Graeffe, 1868.

This species is named in honour of Albert Mousson who pioneered the description of the Fiji diplommatinid fauna.

Shell dextral, small, bulb inconspicuous, columellaris visible in frontal view forming a short horizontal lamella, bulb lamella visible as a fine white line in frontal apertural view.

Shell dextral, small, broadly oval, whitish to greenish; protoconch acute, granulated; last whorl not constricted, slightly ascending; bulb inconspicuous; umbilicus slit-like, periomphalum narrow; sculpture of teleoconch whorls with widely spaced ribs; aperture subquadrate, with two ear-like processes, simple, adhered to the last whorl; peristome with a labial callus; columellaris visible in frontal view; internally, columellaris forming a short horizontal lamella coiling into the interior of the shell; bulb lamella present, visible as a fine white line in frontal apertural view.

Operculum corneous, strongly concave, with a long lamella on the outer surface, internally smooth, OD = 0.7.

Holotype (Fig. 95): H = 3.76; D = 2.3; PH = 1.69; PD = 1.72; W = 6.

Figures 95–97. 

Palaina alberti sp. n. 95 Holotype ZMZ 526680, Viti Levu, Nagara Island, H = 3.76 mm 96 paratype, last whorl opened to show internal lamellae (enlarged, not to scale) 97 operculum 97a inner surface 97b outer surface. Figure 95 ×10, Figure 97 ×40 magnification.

Only known from the type locality.

Palaina alberti sp. n. was identified by Mousson as “Dipl. Godeffroyana var. latecostata”, but can easily be separated from that species by its dextral shell. Additionally, it differs from P. latecostata by the columellaris, which in P. alberti is visible in the aperture, and forms a horizontal lamella. No dextral Palaina species is currently known from Fiji.

Holotype MNHN IM-2000-27453, paratypes MNHN/173 IM-2000-27454, NMBE 516861/20. Type locality: Viti Levu, Qalimare karst, East of Natawatawadi, 40 m, dry forest, -17.9816 177.6266, leg. Bouchet, 21.08.1998.

Adjective formed from the Latin noun flamma = fire, diminutive flammula, to describe the colour pattern of this species.

Shell sinistral, broadly oval, with a pattern of brown axial flames, large bulb, whorls with widely spaced ribs and occasionally interspersed smaller ribs, columella twisted with a truncate basal tooth.

Shell sinistral, broadly oval, protoconch acute, granulated; basic shell colour yellowish to white, with a pattern of brown axial flames between the ribs; last whorl not constricted, with a large bulb; teleoconch sculpture of widely spaced ribs with occasionally interspersed smaller ribs, rib pattern constant throughout the whole shell; fine spiral threads visible on the upper teleoconch whorls (high magnification required); last whorl slightly ascending; aperture circular, sometimes with a double lip, broadly adhered to the last whorl; umbilicus closed, periomphalum narrow; columella twisted, forming a narrow lamella, and ending in a truncate basal tooth; bulb lamella present.

Operculum flat, corneous, multispiral, with a short apophysis, OD = 0.61.

Holotype (Fig. 98): H = 3.45; D = 1.81; PH = 1.25; PD = 1.31; W = 7.

Figures 98–100. 

Palaina flammulata sp. n. 98 Holotype MNHN IM-2000-27453, Viti Levu, Qalimare karst, east of Natawatawadi, 40 m, H = 3.45 mm 99 paratype, last whorl opened to show internal lamellae (enlarged, not to scale) 100 operculum 100a inner surface 100b outer surface. Figure 98 ×10, Figure 100 ×40 magnification.

(Fig. 170). Only known from the type locality.

Palaina flammulata sp. n. is very similar to P. subregularis, but differs from it by having a large bulb with a strong bulb lamella, irregular ribbing pattern, and a narrow columellar lamella. P. parietalis sp. n. and P. truncata sp. n. differ by possessing a parietalis.

Holotype MNHN IM-2000-27455, paratypes MNHN/174 IM-2000-27456, NMBE 516862/20. — Viti Levu, Nakorosule limestone outcrop, 30 m, degraded forest, -17.7734 178.2517, leg. Bouchet & Dayrat, 16.02.1999.

ZMZ 526686a/9, Viti Levu, Tatatau, Graeffe 1872; Viti Levu, Saweni karst, 50–60 m, dry forest, -17.9032 177.7983, leg. Bouchet, 22.08.1998, MNHN/265, NMBE 516898/20; Viti Levu, Wailotua karst, 50–80 m, rainforest, -17.7582 178.4166, leg. Bouchet, 25–27.08.1998, MNHN/13, NMBE 516899/5; surroundings of Laselevu village, 80 m, rainforest, -17.7532 178.1416, leg. Bouchet, Warén & Dayrat, 14.02.1999, MNHN/8.

Vanua Levu, surroundings of Waivunia village, 100 m, from washing of vegetation in spring/seeps at head of creek, -16.7866 179.4117, leg. Bouchet, 31.08.1998, MNHN/1. Voli Voli limestone outcrop, 10–30 m, secondary open forest, -17.3374 178.1831, leg. Bouchet, Warén & Dayrat, 18.02.1999, MNHN/1.

Latin adjective glabellus, -a, -um = without hairs.

Shell sinistral, medium sized, light brownish, teleoconch sculpture of widely spaced ribs, above the aperture, ribs weak or missing; columella only slightly reinforced.

Shell sinistral, medium sized, broadly oval, light yellowish brownish; protoconch acute, granulated; last whorl not constricted, bulb of moderate size; teleoconch sculpture of widely spaced ribs, rib pattern constant throughout the whole shell; above the aperture, ribs becoming weak or are missing; last whorl slightly ascending; aperture circular, with a double lip, broadly adhered to the last whorl; umbilicus closed, periomphalum narrow; columella only slightly reinforced, bulb lamella weak.

Operculum flat, corneous, outer surface with thick concentric lamellae, inner surface smooth, concave, with a short apophysis, OD = 0.78.

Holotype (Fig. 101): H = 3.48; D = 1.95; PH = 1.24; PD = 1.21; W = 6.

Figures 101–103. 

Palaina glabella sp. n. 101 Holotype MNHN 455, Nakorosule limestone outcrop, 30 m, H = 3.48 mm 102 paratype, last whorl opened to show internal lamellae (enlarged, not to scale) 103 operculum 103a inner surface 103b outer surface. Figure 101 ×10, Figure 103 ×40 magnification.

(Fig. 170). Central to eastern area of Viti Levu. The specimens from Vanua Levu and Voli Voli (Viti Levu) are not fully characteristic and may belong to another yet undescribed species.

P. glabella sp. n. is very close to P. labeosa sp. n. and P. ascendens, but the latter differ by their reinforced lip, subquadrate aperture and the dense ribbing pattern of the area above the aperture.

Holotype MNHN IM-2000-27457, paratypes MNHN/169 IM-2000-27458, NMBE 516863/20. — Viti Levu, Wailotua karst, 50–80 m, rainforest, -17.7582 178.4166, leg. Bouchet, 25–27.08.1998.

Viti Levu, Waivisa karst, 50–80 m, rainforest, -17.6879 178.4033, leg. Bouchet, 27.08.1998, MNHN/77, NMBE 516900/15.

This species is dedicated to Klaus Kittel, who sorted the micro land snails from the Fiji leaf litter, and recognized the extent of the diplommatinid radiation.

Shell sinistral, small, yellowish, bulb laterally compressed, oblique to the shell’s axis, columella obliquely twisted, with a basal lamellar callus.

Shell sinistral, small, oval, whitish to yellowish; protoconch acute, granulated; last whorl not constricted, ascending; bulb well developed, laterally compressed, oblique to the shell’s axis with a deep basal depression; suture very deep, whorls well rounded; umbilicus closed, periomphalum narrow; sculpture of teleoconch whorls with widely spaced ribs, ribbing pattern denser on the last 1.5 whorls; aperture circular, with a double lip, adhered to the last whorl, but parietal callus slightly detaching; oblique view into the aperture revealing a strong columellaris; internally, columella obliquely twisted, truncate in the lower half forming a basal lamellar callus, parietum with a very long parietalis in front of the bulb; a strong bulb lamella present.

Operculum corneous, flat, smooth, with a small apophysis, OD = 0.47.

Holotype (Fig. 104): H = 2.51; D = 1.39; PH = 0.94; PD = 1.02; W = 6.5.

Figures 104–106. 

Palaina kitteli sp. n. 104 Holotype MNHN 457, Viti Levu, Wailotua karst, H = 2.51 mm 105 paratype, last whorl opened to show internal lamellae (enlarged, not to scale) 106 operculum 106a inner surface 106b outer surface. Figure 104 ×10, Figure 106 ×40 magnification.

(Fig. 170). eastern area of Viti Levu.

P. kitteli sp. n. is unique in having an almost lamellar bulb, which is well rounded in all other species, particularly in P. tuberosissima, which is otherwise very close in many other shell characters. The latter species differs by its spatulate parietalis, and its bifid columellaris.

Holotype MNHN IM-2000-27459, paratypes MNHN/16 IM-2000-27460, NMBE 516864/2. — Viti Levu, Waivisa karst, 50–80 m, rainforest, -17.6879 178.4033, leg. Bouchet, 27.08.1998.

Viti Levu, surroundings of Laselevu village, 80 m, rainforest, -17.7532 178.1416, leg. Bouchet, Warén & Dayrat, 14.02.1999, MNHN/4.

Latin adjective labeosus, -a, -um = with a thick lip.

Shell sinistral, medium sized, brownish, whorls with moderately spaced ribs, ribbing pattern above the aperture much denser, aperture subquadrate, peristome reinforced by a strong labial callus, operculum with several concentric lamellae.

Shell sinistral, medium sized, broadly oval, brownish to yellowish; protoconch acute, granulated; last whorl not constricted, slightly ascending; bulb well developed; umbilicus closed, periomphalum narrow; sculpture of teleoconch whorls with moderately spaced ribs, ribbing pattern above the aperture much denser; aperture subquadrate, double lipped, adhered to the last whorl; peristome reinforced by a strong labial callus; by oblique view into the aperture columellaris invisible; internally, columella only slightly reinforced; bulb demarcated by a faint bulb lamella.

Operculum corneous, outer surface with several concentric lamellae and a single, short raised lamella; internal surface concave, smooth, OD = 0.67.

Holotype (Fig. 107): H = 3.45; D = 1.94; PH = 1.19; PD = 1.21; W = 5.5.

Figures 107–109. 

Palaina labeosa sp. n. 107 Holotype MNHN IM-2000-27459, Viti Levu, Waivisa Karst, 50–80 m, H = 3.45 mm 108 paratype, last whorl opened to show internal lamellae (enlarged, not to scale) 109 operculum 109a inner surface 109b outer surface. Figure 107 ×10, Figure 109 ×40 magnification.

(Fig. 170). central and northeastern part of Viti Levu.

For a differential diagnosis, refer to P. glabella sp. n. From the conchologically similar P. ascendens, P. labeosa sp. n. differs by possession of a bulb, and the columellar labrum, which is characterised by the presence of a tooth in P. ascendens.

Holotype MNHN IM-2000-27461, paratypes MNHN/207 IM-2000-27462, NMBE 516865/20. — Viti Levu, Saweni karst, 50–60 m, dry forest, -17.9032 177.7983, leg. Bouchet, 22.08.1998.

ZMZ 526683/4, Fiji, Viti Levu, Island of Nagara, ex Godeffroy 1882 [as latecostata Mousson].

Latin adjective derived from the noun paries = wall.

Shell sinistral, small, white, bulb reduced, teleoconch whorls with widely spaced ribs, columella twisted forming a triangular lamella, palatalis and an elongate parietalis present.

Shell sinistral, small, elongate oval, white to faintly yellow; protoconch acute, granulated; last whorl not constricted, slightly ascending; bulb reduced, internally demarcated by a faint bulb lamella; umbilicus closed, periomphalum narrow; sculpture of teleoconch whorls with widely spaced ribs, ribbing pattern above the aperture somewhat denser; aperture suboblique, simple, adhered to the last whorl; by oblique view into the aperture columellaris almost invisible; internally, columella twisted, forming a broad triangular lamella, opposite with a perpendicular palatalis, parietum with an elongate parietalis.

Operculum corneous, outer surface with several indistinct concentric lamellae and a single, short raised lamella; internal surface concave, smooth, OD = 0.55.

Holotype (Fig. 110): H = 3.3; D = 1.63; PH = 1.16; PD = 1.18; W = 7.

Figures 110–112. 

Palaina parietalis sp. n. 110 Holotype MNHN 4 IM-2000-27461, Viti Levu, Saweni karst, 50–60 m, H = 3.3 mm 111 paratype, last whorl opened to show internal lamellae (enlarged, not to scale) 112 operculum 112a inner surface 112b outer surface. Figure 110 ×10, Figure 112 ×40 magnification.

(Fig. 170). beside the 19th century record, only known from the type locality.

P. parietalis sp. n. is close to P. subquadrata sp. n. and P. latecostata, but has a strong parietalis and a palatalis, lacking in the latter two species, which can easily be seen by oblique view into the shell.

Holotype MNHN IM-2000-27463, paratypes MNHN/31 IM-2000-27464, NMBE 516866/5. — Viti Levu, Wailotua karst, 50–80 m, rainforest, -17.7582 178.4166, leg. Bouchet, 25–27.08.1998.

Viti Levu, Waivisa karst, 50–80 m, rainforest, -17.6879 178.4033, leg. Bouchet, 27.08.1998, MNHN/21, NMBE 516901/3; Viti Levu, Wailotua karst, near summit Uluitova, 370–390 m, rainforest, -17.7582 178.4166, leg. Bouchet, 28.08.1998, MNHN/1.

Latin adjective sulcatus, -a, -um = with a furrow.

Shell sinistral, small broadly oval, yellow to greenish, bulb reduced, aperture with a large horizontal columellaris, a strong palatalis corresponding to a deep furrow on the dorsal side of the last whorl, elongated parietalis present.

Shell sinistral, small to medium sized, broadly oval, faintly yellow to greenish; protoconch acute, granulated; last whorl not constricted, ascending; bulb reduced; umbilicus closed, periomphalum narrow; sculpture of teleoconch whorls with widely spaced ribs, area above the aperture almost smooth; aperture subquadrate, with a double lip, and two ear-like processes on the upper edges of the peristome; adhered to the last whorl; aperture with a large horizontal columellaris in a central position; internally, columellaris forming a large horizontal lamella of approximately one whorl, slightly bent upwards towards its end; opposite a strong palatalis corresponding to a deep furrow on the dorsal side of the last whorl; an elongated parietalis and a faint bulb lamella present.

Operculum corneous, outer surface with indistinct concentric lamellae and a single, short raised lamella; internal surface concave, smooth, OD = 0.66.

Holotype (Fig. 113): H = 3.13; D = 1.92; PH = 1.31; PD = 1.38; W = 5.

Figures 113–115. 

Palaina sulcata sp. n. 113 Holotype MNHN IM-2000-27463, Viti Levu, Wailotua karst, 50–80 m, H = 3.13 mm 114 paratype, last whorl opened to show internal lamellae (enlarged, not to scale. 115 operculum 115a inner surface 115b outer surface. Figure 113 ×10, Figure 115 ×40 magnification.

(Fig. 170). Eastern Viti Levu.

P. sulcata sp. n. is unmistakable for its columellaris, which is unique among all Fiji diplommatinids, because it is formed like a classical columellaris, i.e. a horizontal lamella running into the interior of the shell twisting around the columella. The columella itself is not transformed. Another unique feature is the strong palatalis with the corresponding furrow in the last whorl.

P. sulcata sp. n. is provisionally placed in Palaina, because there is no bulb formation in Diancta, but a constriction of the last whorl, and the columella is usually transformed to form a columellar plate, not present here in P. sulcata.

Holotype MNHN IM-2000-27465, paratypes MNHN/4 IM-2000-27466. — Viti Levu, surroundings of Nandele village, 50 m, secondary agroforest with Albizia and coffee shrubs, -17.7083 177.5249, leg. Bouchet, Warén & Dayrat, 17.03.1999.

Latin adjective, past participle of verb truncare = to truncate.

Shell sinistral, small, bulb well developed with strong bulb lamella, columella obliquely twisted, truncate, basal tooth-like callus, one parietalis

Shell sinistral, small, oval, whitish to greyish; protoconch acute granulated; last whorl not constricted, slightly ascending; bulb well developed; umbilicus closed, periomphalum narrow; sculpture of teleoconch whorls with widely spaced ribs; aperture circular, simple, adhered to the last whorl; oblique view into the aperture revealing a strong columellaris; internally, columella obliquely twisted, truncate in the lower third with a basal tooth-like callus, parietum with a small parietalis in front of the bulb and a parietal furrow or depression next to the columella; a strong bulb lamella present.

Operculum unknown.

Holotype (Fig. 116): H = 3.29; D = 1.63; PH = 1.12; PD = 1.23; W = 6.5.

Figures 116–117. 

Palaina truncata sp. n. 116 Holotype MNHN IM-2000-27465, Viti Levu, surroundings of Nandele village, H = 3.29 mm 117 paratype, last whorl opened to show internal lamellae (enlarged, not to scale). Figure 116 ×10 magnification.

(Fig. 170). Only known from the type locality.

P. truncata sp. n. is close to P. tuberosissima sp. n., but this species has a large parietalis, a lamella in the bulb, and a deep palatalis. It is also similar to P. subregularis, but differs from it in having the twisted columella, a parietalis and a bulb.

Holotype MNHN IM-2000-27467, paratypes MNHN/183 IM-2000-27468, NMBE 516867/20. — Viti Levu, limestone outcrop SE of Nambukulevu, 230 m, rainforest, -18.1366 177.8149, leg. Bouchet, Warén & Dayrat, 20.02.1999.

Viti Levu, Saweni karst, 50–60 m, dry forest, -17.9032 177.7983, leg. Bouchet, 22.08.1998, MNHN/1; Viti Levu, Tuvu karst, 50 m, dry forest, -17.9332 177.7067, leg. Bouchet, 23.08.1998, MNHN/2.

Adjective, derived from Latin tuber = swelling, and suffix -issimus, -a, -um = very.

Shell sinistral, small, faint yellowish, bulb well developed, whorls with widely spaced ribs, peristome with labial callus, columella obliquely twisted with a second columellaris beyond the bulb, a very long spatulate parietalis and a strong palatalis inside the bulb.

Shell sinistral, small, broadly oval, faint yellowish; protoconch acute, granulated; last whorl not constricted, slightly ascending; bulb well developed; umbilicus closed, periomphalum narrow; sculpture of teleoconch whorls with widely spaced ribs, area above the aperture almost smooth; aperture circular, simple, adhered to the last whorl; peristome reinforced by a strong labial callus, and two ear-like processes on the upper edges of the peristome; by oblique view into the aperture columellaris visible; internally, columella obliquely twisted and reinforced, truncate in the lower half forming a basal knob-like tooth, and a second columellaris beyond the bulb; parietum with a very long spatulate parietalis in front of the bulb; a strong palatalis inside the bulb present.

Operculum corneous, outer surface with several concentric lamellae and a single, short raised lamella; internal surface concave, smooth, OD = 0.67.

Holotype (Fig. 118): H = 2.97; D = 1.61; PH = 1.12; PD = 1.21; W = 6.

Figures 118–120. 

Palaina tuberosissima sp. n. 118 Holotype MNHN IM-2000-27467, Viti Levu, limestone outcrop SE of Nambukulevu, 230 m, H = 2.97 mm 119 paratype, last whorl opened to show internal lamellae (enlarged, not to scale) 120 operculum 120a inner surface 120b outer surface. Figure 118 ×10, Figure 120 ×40 magnification.

(Fig. 170). Central Viti Levu.

P. tuberosissima sp. n. is close to P. tuberosa, which differs by having a dense ribbing pattern on the area above the aperture. Possession of a second columellaris makes this species unique, as there is no other diplommatinid species on Fiji with this character.