Pseudomphalus Ancey, 1882

Hausdorf, Bernhard, 2013, Revision of the endemic genera Diplomphalus and Pseudomphalus from New Caledonia (Gastropoda, Rhytididae), Zoosystema 35 (1), pp. 69-88 : 84-87

Genus Pseudomphalus Ancey, 1882

Pseudomphalus Ancey, 1882: 86 . Type species (subsequent designation by Wenz & Zilch, 1960: 551): Helix fabrei Crosse, 1875 (= Helix megei Lambert, 1873 ).

DIAGNOSIS. — Pseudomphalus differs from Diplomphalus in the short penis with a large conic flagellum, the fusiform vas deferens and the larger shell (9.2-17.1 mm) with rounded, widely overlapping whorls, a weaker sculpture and a narrower umbilicus.

Pseudomphalus megei (Lambert, 1873) ( Figs 3B ; 4E ; 5B ; 6C, D ; 9 ; 11 )

Helix megei Lambert, 1873a: 136 ; type locality: “Baie du Sud”, New Caledonia ; 1873b: 356, pl. 14, fig. 3. — Gassies 1880: 30, pl. 1, fig. 20.

Diplomphalus fabrei Crosse, 1875: 136 , pl. 6, fig. 1; type locality: “Baie du Sud”, New Caledonia. — Thiele 1931: 725, fig. 766 .

Diplomphalus megei var. β – Crosse 1875: 138, pl. 6, fig. 2.

Helix fabrei – Gassies 1880: 32, pl. 4, fig. 12.

Pseudomphalus fabrei – Ancey 1882: 86. — Schileyko 2000: 752, fig. 979.

Pseudomphalus megei – Ancey 1882: 86.

Diplomphalus (Pseudomphalus) megei – Tryon 1885: 115, pl. 24, figs 59, 60, 82-84. — Crosse 1895: 181.

Revision of Diplomphalus and Pseudomphalus ( Gastropoda , Rhytididae ) from New Caledonia

Diplomphalus (Pseudomphalus) fabrei – Tryon 1885: 115, pl. 24, figs 85-87. — Crosse 1895: 182. — Wenz & Zilch 1960: 551, fig. 1927.

Diplomphalus (Pseudomphalus) megei var. β – Crosse 1895: 181.

Diplomphalus megei – Franc 1957: 176, pl. 23, fig. 232.

TYPE MATERIAL. — D. megei: Baie du Sud , one syntype ( MNHN) ; D. fabrei: Baie du Sud , one syntype ( MNHN 22959 ) .

OTHER MATERIAL EXAMINED. — New Caledonia ( FMNH 36989-36991, 91902; MNHN, among others 4 voucher specimens to Crosse 1875: 138, pl. 6, fig. 2 and Franc 1957: 176, pl. 23, fig. 232; RBINS); Bogui-Col des Rousettes, 270 m alt., 21°24’55”S, 165°26’49”E ( MNHN); Col des Roussettes, 500 m alt., 21°25’13”S, 165°27’53”E ( MNHN); Col d’Amieu, 420 m alt., 21°33’58”S, 165°46’16”E ( MNHN); Mt. Table Unio, 500 m alt., 21°34’44”S, 165°45’06”E ( MNHN); Col d’Amieu, summit, La Foa-Canala highway, 500 m alt., 21°37’S, 165°49’E ( FMNH 158425, 158426); Haute Rivière Bleue, 250-350 m alt., 22°04’27”S, 166°37’10”E ( MNHN); Haute Rivière Bleue, 230 m alt., 22°04’40”S, 166°37’24”E ( MNHN); Piste de la Pourina, 520 m alt., 22°05’00”S, 166°41’45”E ( MNHN); Piste de la Pourina, 150-250 m alt., 22°05’58”S, 166°41’17”E ( MNHN); Baie du Sud ( MNHN 22959, one syntype of D. fabrei, MNHN , among others one syntype of D. megei ); Rivière Bleue, 170 m alt., 22°05’59”S, 166°40’01”E ( MNHN); Rivière Bleue, 160 m alt., 22°06’13”S, 166°39’16”E ( MNHN); Rivière Blanche, 160-170 m alt., 22°08’09”S, 166°38’20”E ( MNHN); Rivière Blanche, Parc de réadaption des Cagous ( MNHN); near Mt. Ouenarou, 30 km NE of Nouméa (towards Yaté) ( FMNH 159232); Waho, 20 m alt., 22°10’00”S, 166°56’23”E ( MNHN); Mont Guemba, 450 m alt., 22°10’22”S, 166°56’10”E ( MNHN); N of col de Mouirange, 220- 230 m alt., 22°11’57”S, 166°39’52”E ( MNHN); St. Gabriel towards mine Ni, 200 m alt., 22°12’00”S, 166°58’00”E ( MNHN); Haute Napouéredjeine, 250 m alt. ( MNHN); N of Grand Lac, 310 m alt., 22°13’09”S, 166°55’03”E ( MNHN); S of Grand Lac ( Schileyko, 2000); Pic du Pin, E slope, 250 m alt., 22°14’07”S, 166°49’45”E ( MNHN); Nouméa, 22°16’S, 166°27’E ( MNHN); Forêt Nord, 200-250 m alt., 22°17’00”S, 166°53’00”E ( MNHN); Prony, 22°19’S, 166°49’E ( MNHN; RBINS); Baie du Prony ( FMNH 110157, 123621; RBINS); Kwa Néïe (Mts. Néngoné), 470 m alt., 22°19’09”S, 166°55’12”E ( MNHN).

DISTRIBUTION ( FIG. 9 ). — Pseudomphalus megei is restricted to two disjunct areas in the southern half of New Caledonia, one between the Col des Rousettes and Mt. Table Unio and one at the southern tip of the island. DESCRIPTION

Shell ( Figs 5B ; 11 ; Table 2) biconcave; spire deeply sunken, with 5.75-6.50 rounded whorls; protoconch with a pitted microsculpture with indistinct spiral lines; teleoconch rib-striated; brownish-corneous; aperture narrow crescentic; upper insertion of peristome not descending towards aperture; peristome expanded, not reflexed, not or slightly thickened inside; insertions of peristome connected by a very weak callus; aperture without lamellae or folds; umbilicus wide.

Genitalia ( Fig. 4E ). One specimen from Rivière Bleue was examined.The genital pore is situated posterior to the right ommatophore.The genitalia run to the right of the right ommatophoral retractor. Penis short, with long conic flagellum. There is a V-shaped pilaster inside penis. Penial retractor inserts at base of flagellum. In the examined specimen the penis retractor fused with the tentacle retractors and there was no branch inserting at vagina as in the specimen figured by Schileyko (2000: 752, fig. 979). Vas deferens fusiform, narrow at the insertion at penis, but becoming broad in its middle section.Vagina much shorter than free oviduct. Bursa of bursa copulatrix short, slightly enlarged.

Mantle collar and pallial complex ( Fig. 3B ).Mantle collar broad (integument inserts deeply at the mantle edge), forming a simple rim around the body without large lobes. Heart more than half as long as kidney, continuing anteriorly into indistinct pulmonary vein. Lung without additional coarse venation. Kidney long, opening anteriorly into reflexed primary ureter. Primary ureter running to the extreme posterior corner of the pulmonary cavity, where it transitions into the tubular secondary ureter, running along hindgut to the pnemostome. There is no distinct mantle gland posterior to the mantle collar.

Radula ( Fig. 6C, D ). Narrow; central teeth missing, only a rudimentary basal structure visible; 28 long, unicuspid lateral teeth on each side in V-shaped rows; broader basal part of lateral teeth attached with a small projection to the membrane, apical part curved towards the centre; lateral teeth becoming smaller towards the margin of the radula. In the figured radula two columns are formed abnormally, one with rudimentary teeth and one with split, bicuspid teeth.

REMARKS

Diplomphalus fabrei was correctly synonymised with Pseudomphalus megei by Franc (1957). It was based on specimens that have more whorls and are consequently larger, but they cannot otherwise be distinguished from typical Pseudomphalus megei .

Figures

FIG. 3. — Diplomphalus and Pseudomphalus spp., protoconch: A, Diplomphalus mariei (Crosse, 1867), New Caledonia: Oua-Tom (MNHN); B, Pseudomphalus megei (Lambert, 1873), New Caledonia: Bogui-Col des Rousettes (MNHN). Scale bars: 100 µm.

FIG. 4. — Diplomphalus and Pseudomphalus spp., genitalia:A, Diplomphalus mariei (Crosse,1867),New Caledonia:Col de Pétchékara (MNHN);B, idem,internal structure of the penis;C, Diplomphalus solidula Tryon,1885,New Caledonia:Baie Ngo (MNHN);D, Diplomphalus vaysseti (Marie, 1871),New Caledonia:Col d’Amos (MNHN);E, Pseudomphalus megei (Lambert,1873),New Caledonia:sud du Grand Lac (reproduced from Schileyko 2000: fig. 979B). Abbreviations: at, genital atrium; bc, bursa copulatrix; fl, flagellum; o, free oviduct; p, penis; rp, penial retractor; spo, spermoviduct; v, vagina; vd, vas deferens. Scale bars: A, C, D, 1.0 mm; B, 0.5 mm; E, not to scale.

FIG. 5. — Diplomphalus and Pseudomphalus spp., mantle collar and pallial complex: A, Diplomphalus mariei (Crosse, 1867), New Caledonia, Col de Pétchékara (MNHN); B, Pseudomphalus megei (Lambert), New Caledonia, Rivière Bleue, 170 m alt. (MNHN). Abbreviations: aur, auricle; k, kidney; mc, mantle collar; pc, pericardium; ps, pneumostome; pu, primary ureter; pv, pulmonary vein; rec, rectum; su, secondary ureter; ven, ventricle. Scale bars: 1 mm.

FIG. 6.— Diplomphalus and Pseudomphalus spp.,radula.A, B, Diplomphalus mariei (Crosse,1867),New Caledonia,Col de Pétchékara (MNHN); C, D, Pseudomphalus megei (Lambert, 1873), New Caledonia, Rivière Bleue, 170 m alt. (MNHN). Scale bars: A, D, 10 µm; B, 2 µm; C, 50 µm.

FIG. 9. — Distribution of Diplomphalus cabriti (Gassies,1863) and Diplomphalus montrouzieri (Souverbie,1858) (•) and Pseudomphalus megei (Lambert, 1873) (⚫).

FIG. 11. — Pseudomphalus megei (Lambert, 1873) shells; A, New Caledonia, Baie du Sud (MNHN); B, New Caledonia, Baie du Sud (syntype of D. fabrei, MNHN 22959). Scale bar: 2.0 mm.