Diplomphalus Crosse & Fischer, 1872

Hausdorf, Bernhard, 2013, Revision of the endemic genera Diplomphalus and Pseudomphalus from New Caledonia (Gastropoda, Rhytididae), Zoosystema 35 (1), pp. 69-88 : 70-84

Genus Diplomphalus Crosse & Fischer, 1872

Diplomphalus Crosse & Fischer, 1872: 288 . Type species (by monotypy): Helix cabriti Gassies, 1863 .

DIAGNOSIS. — Diplomphalus is characterised by a small (4.4-9.0 mm) biconcave shell with a deeply sunken spire,

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

tightly coiled whorls with an edge at the upper and the basal side and a very wide umbilicus.

Diplomphalus mariei (Crosse, 1867) ( Figs 1 ; 2 ; 3A ; 4A, B ; 5 ; 6A, B )

Helix mariei Crosse, 1867a: 211 ; type locality: “Koe in vicinio urbis Noumea dictae, Novae-Caledonidae humi sub arbore reperta”, New Caledonia. — Crosse 1867b: 312, pl. 11 fig. 1. — Gassies 1871: 38, pl. 1 fig. 5.

Diplomphalus mariei – Crosse & Fischer 1873: 23. — Tryon 1885: 113, pl. 25, figs 6, 7 (in part). — Kobelt 1904: 88, pl. 14 figs 3-5 (in part). — Franc 1957: 178, pl. 23, fig. 236 (in part).

Helix seberti Marie, 1881: 241 ; type locality: “ Kanala ”, New Caledonia. N. syn .

Diplomphalus (Diplomphalus) mariei – Crosse 1895: 175 (in part).

Diplomphalus (Diplomphalus) seberti – Crosse 1895: 177, pl. 8, fig. 1.

Diplomphalus seberti – Kobelt 1904: 89, pl. 14, figs 9-11. Franc 1957: 177, pl. 23, fig. 234.

Diplomphalus fischeri Franc, 1953: 81 , fig. 1; type locality: “ Nouvelle-Calédonie ” ; 1957: 178, pl. 23, fig. 237. N. syn.

TYPE MATERIAL. — H. mariei: Koé , 22°08’S, 166°28’E, 3 possible syntypes ( NHMUK 1883.11.10.842-844) ; H. seberti: Canala , 3 syntypes ( MNHN; see also Crosse 1895: 177, pl. 8, fig. 1) ; D. fischeri : New Caledonia, many syntypes ( MNHN 22960-22962 ; see also Franc 1957: 178, pl. 23, fig. 237) .

OTHER MATERIAL EXAMINED. — New Caledonia ( FMNH 36988 ; MNHN, among others voucher specimens to Franc 1957: 177, pl. 22, fig. 235 and p. 178, pl. 23, fig. 236; RBINS) ; Forêt Plate, 540 m alt., 21°08’57”S, 165°06’23”E ( MNHN) ; Mt. Kopeto , 800 m alt., 21°10’39”S, 165°00’38”E ( MNHN) ; Adio, valley, 180 m alt., 21°14’44”S, 165°14’46”E ( MNHN) ; Adio , caves, 21°15’36”S, 165°14’18”E ( MNHN) ; Barrage de la Neaoua (Ouen Sieu), 500 m alt., 21°21’57”S, 165°32’35”E ( MNHN; ZMH 79086) ; Bogui, 150 m alt., 21°23’21”S, 165°26’30”E ( MNHN) ; Mines Emma-Pinpin, 50 m alt., 21°23’54”S, 165°16’51”E ( MNHN) ; Col des Roussettes , 200 m alt., 21°24’53”S, 165°26’44”E ( MNHN) ; Col des Roussettes , 270 m alt., 21°24’53”S, 165°26’44”E ( MNHN) ; Col des Roussettes , E side, Bourail-Houailou, 365 m alt. ( FMNH 158377 ) ; Bogui-Col des Roussettes , 270 m alt., 21°24’55”S, 165°26’49”E ( MNHN) ; Mé Aiu, 730 m alt., 21°29’15”S, 165°51’00”E ( MNHN) ; Koh, 150 m alt., 21°32’00”S, 165°48’50”E ( MNHN) ; Canala, 21°32’S, 165°57’E ( FMNH 73942 , 110159 ; MNHN; RBINS) ; Mé Ori, 530 m alt., 21°32’18”S, 165°40’22”E ( MNHN) ; Gelima, Caférie, 80 m alt., 21°32’24”S, 165°58’36”E ( MNHN) ; Mé Ori, 530 m alt., 21°32’37”S, 165°40’21”E ( MNHN) ; Table-Unio, 850-1000 m alt., 21°33’36”S, 165°45’55”E ( MNHN) ; Bourail , 21°34’S, 165°29’E ( FMNH 72860 ) ; 1.5 km inland from Pierced Rock, 8 km W of Bourail , 60 m alt. ( FMNH 158347 ) ; Dothio-Col de Pétchékara , 340 m alt., 21°34’32”S, 166°06’32”E ( MNHN) ; Col de Pétchékara , 450 m alt., 21°34’41”S, 166°05’48”E ( MNHN) ; Oua- Oué, 50 m alt., 21°37’00”S, 165°35’07”E ( MNHN) ; Col d’Amieu, summit, La Foa-Canala highway, 500 m alt., 21°37’S, 165°49’E ( FMNH 158417 , 158428 ) ; Nakada, 500 m alt., 21°38’57”S, 166°03’08”E ( MNHN) ; Farino , 21°40’S, 165°46’E ( RBINS) ; Fonwhary , 21°41’S, 165°47’E ( RBINS) ; Mine de Moindou , 21°42’S, 165°41’E ( FMNH 110158 ; RBINS) ; Mt. Ningua , 1000 m alt., 21°44’24”S, 166°09’03”E ( MNHN) ; Col de Nassirah , 250 m alt., 21°46’44”S, 166°04’14”E ( MNHN) ; Oua-Tom, 130 m alt., 21°47’15”S, 165°54’00”E ( MNHN) ; Oua Tom, 20 km N of Boulouparis , gully, 60 m alt., 21°48’S, 165°54’E ( FMNH 158400 , 158411 in part) ; Mont Mou, 400 m alt., 22°04’28”S, 166°19’46”E ( MNHN) ; Col de la Pirogue, Mont Mou, 450 m alt., 22°05’S, 166°20’E ” ( FMNH 144255 ) ; Monts des Koghis , 18 km N of Nouméa, 450 m alt. ( FMNH 158280 ) ; Nouméa , 22°16’S, 166°27’E ( MNHN) .

DISTRIBUTION ( FIG. 1 ). — Diplomphalus mariei is restricted to the central part of New Caledonia. Its range overlaps those of D. solidula Tryon, 1885 and D. vaysseti ( Marie, 1871) , demonstrating that it is specifically distinct from these species. At some localities it has been found even syntopically with D. vaysseti . There is an old sample that is allegedly from Ouégoa (RBINS) in the northern part of the main island of New Caledonia where D. mariei has not been found for more than a century, although several expeditions have collected there.

DIAGNOSIS. — Diplomphalus mariei differs from D. solidula and D. vaysseti in a usually broader aperture (da/ha = 0.6-1.7 in D. mariei , 0.5-0.7 in D. solidula , 0.4-0.8 in D. vaysseti ) and a callus forming an arcuate lamella projecting from the body whorl. The whorls of D. mariei insert basally close to the edge of the previous whorl, whereas the whorls of D. solidula and D. vaysseti insert basally farther outside (and thus below) the edge of the previous whorl. Therefore the umbilical concavity of D. solidula and D. vaysseti is more stepped than that of D. mariei .

DESCRIPTION

Shell ( Fig. 2 ; 3A ; Table 1) biconcave; spire deeply sunken, with 6.75-7 whorls with an edge at upper side, which can be compressed to form a keel, and an edge at basal side; protoconch initially smooth, then with microscopic spiral striae; teleoconch with moderately coarse, regular ribs (20-42 per quarter on upper side of body whorl) at upper and basal side that can split into 2 finer ribs at outer side of whorls between upper and lower edge and microscopic spiral threads; brownishcorneous with reddish-brown diagonal stripes; aperture pear-shaped, wider below than above; upper insertion of peristome distinctly descending towards aperture; peristome expanded, slightly reflexed, slightly thickened; insertions of peristome connected by a strong callus forming an arcuate lamella that projects from body whorl, especially in its middle; aperture without lamellae or folds; umbilicus wide.

Genitalia ( Fig. 4A, B ). Specimens from Col de Pétchékara and Col de Nassirah were examined. The genital pore is situated just posterior to the right ommatophore. The genitalia run to the right of the right ommatophoral retractor.Penis long and slightly broadened near the subterminal insertion of the vas deferens. There are straight longitudinal pilasters in proximal part of penis. Two strong longitudinal pilasters form a U-shaped structure. Opposite of the longitudinal pilasters, the penial wall is sculptured by wavy transversal pilasters. The narrow distal part of penis is sculptured with longitudinal pilasters. Penial retractor inserting terminally at penis and at diaphragm. Vas deferens divided in thin distal section running along penis towards atrium and thicker proximal section along vagina and free oviduct. Vagina shorter than free oviduct. Oviduct consisting of short narrower distal section and broader, longer glandular proximal section. Reservoir of bursa copulatrix only slightly broadened.

Mantle collar and pallial complex ( Fig. 5 ). Mantle collar broad (integument inserts deeply at the mantle edge), forming a narrow rim around the body without large lobes; only the region around the pneumostome is distinctly thickened; this thickening may form minute lobes at the edge. Heart about 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, opening shortly before mantle collar, continuing anteriorly as a groove. There is no distinct mantle gland posterior to the mantle collar. Radula ( Fig. 6A, B ). Narrow; central teeth rudimentary, straight, stylet-like; 8 about equally long, slender, unicuspid lateral teeth on each side in V-shaped rows; basal half of lateral teeth attached with a small projection to the membrane, apical part curved towards the centre.

REMARKS

Helix seberti Marie, 1881 and Diplomphalus fischeri Franc, 1953 are synonymised here with Diplomphalus mariei , because they fall into the range of variation of this species.

Diplomphalus solidula Tryon, 1885 ( Figs 4C ; 7 ; 8A )

Diplomphalus mariei var. β – Crosse 1874: 387, pl. 12, fig. 1.

Diplomphalus mariei var. solidula Tryon, 1885: 114 , pl. 25, fig. 10; type locality: “Baie du Sud” (see Crosse 1874: 387), New Caledonia .

Diplomphalus (Diplomphalus) mariei – Crosse 1895: 175 (in part).

Diplomphalus (Diplomphalus) mariei var. β Solidula – Crosse 1895: 176.

Diplomphalus mariei var. solidula – Kobelt 1904: 89.

Diplomphalus mariei – Franc 1957: 178 (in part, not Crosse 1867).

Diplomphalus vaysseti – Franc 1957: 177, pl. 22, fig. 235 (in part, not Marie 1871).

TYPE MATERIAL. — D. mariei var. solidula: Baie du Sud , syntype ( MNHN; voucher specimen of Crosse 1874: 387, pl. 12, fig. 1) .

OTHER MATERIAL EXAMINED. — New Caledonia ( MNHN, among others the voucher specimen of Franc [1957: 177, pl. 22, fig. 235]; RBINS) ; Baie du Sud ( MNHN; RBINS) ; S of top of Mt. Ouin , 1150- 1200 m alt., 22°00’58”S, 166°28’21”E ( MNHN) ; Vallée Ouinné , 650 m alt., 22°02’23”S, 166°32’28”E

ps

( MNHN); Haute Rivière Bleue, 300 m alt., 22°04’07”S, 166°36’28’”E ( MNHN); Baie du Sud ( MNHN); Piste de la Pourina, 520 m alt., 22°05’00”S, 166°41’45”E ( MNHN); Mt. Kouvélè , E slope, 660 m alt., 22°05’26”S, 166°26’56”E ( MNHN); Rivière Bleue, 150 m alt., 22°05’47”S, 166°39’25”E ( MNHN); 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); Parc à Cagous, Rivière Blanche, 160-170 m alt., 22°08’09”S, 166°38’20”E ( MNHN; ZMH 79089); near Mt. Ouenarou , 30 km NE of Nouméa (towards Yaté ), 250 m alt., 22°10’S, 166°43’E ( FMNH 158273 , 158361 ); Mont Guemba , 200 m alt., 22°10’22”S, 166°56’10”E ( MNHN); Mouirange , 180-250 m alt., 22°12’00”S, 166°39’00”E ( MNHN); Route les Dalmates, Monts Kouanenoa, E of St. Louis, 22°12’S, 166°42’E ” ( FMNH 144227 ) ; Mouirange , 200 m alt., 22°13’19”S, 166°40’14”E ( MNHN) ; S of Grand Lac , 280 m alt., 22°16’31”S, 166°54’00”E ( MNHN) ; Nouméa , Pointe de l’Artillerie, 22°17’S, 166°26’E ( RBINS) ; Forêt Nord , 200-250 m alt., 22°17’00”S, 166°53’00”E ( MNHN) ; Baie Ngo, 30 m alt., 22°18’02”S, 166°42’49”E ( MNHN; ZMH 79085) ; Baie du Prony ( RBINS) ; Kwa Néie (Mts. Néngoné), 470 m alt., 22°19’09”S, 166°55’12”E ( MNHN) .

DISTRIBUTION ( FIG. 7 ). — Diplomphalus solidula is restricted to the part of New Caledonia south of 22°S.

DIAGNOSIS. — Diplomphalus solidula is characterised by a strong callus which extends a little forwards from the aperture and is slightly detached from the body whorl at its margin.

DESCRIPTION

Shell ( Fig. 8A ; Table 1) biconcave; spire deeply sunken, with 6.0-7.25 whorls with an edge at upper side and a weaker edge at the basal side; protoconch smooth; teleoconch with coarse, regular ribs (19-29 per quarter on the upper side of the body whorl) at upper and basal side that usually split into 2-3 finer ribs at outer side of whorls between upper and lower edge and microscopic spiral threads; brownish-corneous with reddish-brown transverse stripes; aperture unequally crescentic, wider below than above; upper insertion of peristome distinctly descending towards aperture; peristome not expanded, not or slightly reflexed, slightly thickened; insertions of peristome connected by a strong callus which extends a little forwards from aperture and is slightly detached from body whorl at its margin; aperture wuthout lamellae or folds; umbilicus wide. Genitalia ( Fig. 4C ). Specimens from Baie Ngo were examined. Penis long and broadened near subterminal insertion of vas deferens. There are straight longitudinal and wavy transversal pilasters inside the penis. Penial retractor inserts terminally at penis and at diaphragm.Vas deferens divided in thin distal section running along penis towards atrium and thicker proximal section along vagina and free oviduct. Vagina shorter than free oviduct. Oviduct consisting of short narrower distal section and broader, longer glandular proximal section.Reservoir of thin bursa copulatrix only slightly broadened.

Diplomphalus vaysseti ( Marie, 1871) ( Figs 4D ; 7 ; 8B )

Helix volutella Gassies, 1858: 70 (not L. Pfeiffer, 1856); type locality: “bois de Balade”, New Caledonia. N. syn.

Helix Cabriti – Gassies 1863: 21, pl. 1, fig. 4 (in part, not Gassies 1863).

Helix cabriti – Crosse 1867b: 315 (in part, not Gassies 1863).

Helix vaysseti Marie, 1871: 325 ; type locality: “dans les montagnes, au cap Colnett”, New Caledonia .

Diplomphalus cabriti – Crosse & Fischer 1873: 22 (in part, not Gassies 1863). — Kobelt 1904: 87 (in part, not Gassies 1863). — Franc 1957: 176 (in part, not Gassies 1863).

Diplomphalus vaysseti – Crosse & Fischer 1873: 23. — Crosse 1874: 388, pl. 12, fig. 2. — Tryon 1885: 113, pl. 25, figs 1-3. — Kobelt 1904: 89, pl. 14, figs 6-8. — Franc 1957: 177 (in part).

Helix vaysseti – Gassies 1880: 33, pl. 1, fig. 21.

Diplomphalus (Diplomphalus) cabriti – Crosse 1895: 173 (in part, not Gassies 1863).

Diplomphalus (Diplomphalus) vaysseti – Crosse 1895: 176.

TYPE MATERIAL. — Unknown.

MATERIAL EXAMINED. — New Caledonia ( FMNH 36986 ; MNHN) ; Col d’Amos, 200 m alt., 20°18’52”S,

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

164°25’20”E ( MNHN) ; Balade, 20°19’S, 164°30’E ( Gassies, 1858); 6.5 km E of Ouegoa , 120 m alt. ( FMNH 158250 , 159347 ) ; 8 km inland from Koumac , 90 m alt. ( FMNH 158300 ) ; Mandjelia, 400 m alt., 20°22’29”S, 164°30’06”E ( MNHN) ; Le Cresson, 20°29’00”S, 164°18’36”E ( MNHN) ; Cap Colnett, 20°30’S, 164°45’E ( Marie 1871); Kaala- Gomen, Konio, “la Cathédrale”, 350-450 m alt., 20°34’30”S, 164°24’12”E ( MNHN) ; Mont Panié near Tao ( FMNH 159344 ) ; Mont Panié, 280 m alt., 20°35’27”S, 164°48’43”E ( MNHN) ; Mont Panié, 580 m alt., 20°35’54”S, 164°48’22”E ( MNHN) ; Thiem, 10-50 m alt., 20°45’43”S, 165°06’23”E ( MNHN) ; Thiem , 90 m alt. ( FMNH 158326 ) ; valley SW of Oua Tilou , 200 m alt., 20°52’03”S, 164°49’49”E ( MNHN) ; Col Tango, way from Bobeitio, 300-350 m alt., 20°58’29”S, 165°00’27”E ( MNHN) ; Monéo, 21°09’36”S, 165°29’31”E ( MNHN) ; Mt. Aoupinié , 600-700 m alt., 21°10’47”S, 165°17’59”E ( MNHN) ; Adio, valley, 180 m alt., 21°14’44”S, 165°14’46”E ( MNHN) ; Adio, caves, 21°15’36”S, 165°14’18”E ( MNHN; ZMH 79087) ; 15 km NE of Poya, inland of Nékliaï , 150 m alt. ( FMNH 158358 ) ; Mé Maoya, 1250 m alt., 21°22’09”S, 165°20’21”E ( MNHN) ; Col des Roussettes , 200 m alt., 21°24’53”S, 165°26’44”E ( MNHN) ; Bogui-Col des Roussettes , 270 m alt., 21°24’55”S, 165°26’49”E ( MNHN) ; Table-Unio, 850-1000 m alt., 21°33’36”S, 165°45’55”E ( MNHN) .

DISTRIBUTION ( Fig. 7 ). — Diplomphalus vaysseti is restricted to the northern part of New Caledonia. The gap between the distribution areas of D. vaysseti and D. solidula is not as large as shown in Figure 7 . There is a juvenile specimen from Oua Tom (FMNH 158411 in part) in the intermediate region which belongs to one of the two species.

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

DIAGNOSIS. — Diplomphalus vaysseti differs from D. solidula and D. mariei in a usually weak callus not detached from the body whorl and an on average denser coiling, i.e. a lower diameter at the same number of whorls. At five whorls the diameter of D. vaysseti varies usually from 2.1-2.7 mm, in D. solidula from 2.7-3.2 mm and in D. mariei from 2.6-3.5 mm. D. vaysseti differs from D. cabriti in a smaller shell (diameter: 4.4-6.5 mm v 8.2-9.0 mm in D. cabriti ).

DESCRIPTION

Shell ( Fig. 8B ; Table 1) biconcave; spire deeply sunken, with 6.5-8 whorls with an edge at upper side and an edge at basal side; protoconch initially smooth, then with microscopic spiral striae; teleoconch with coarse, regular ribs (20-36 per quarter on upper side of body whorl) at upper and basal side that can split into two finer ribs at outer side of whorls between upper and lower edge and microscopic spiral threads; brownish-corneous with a reticulate pattern of reddish-brown diagonal stripes; aperture unequally crescentic, wider below than above; upper insertion of peristome slightly descending towards aperture; upper part of peristome slightly protruding, lower part slightly reflexed, not expanded, slightly thickened; insertions of peristome connected by a weak callus which might extend a little forwards from aperture, but is not detached from body whorl; aperture without lamellae or folds; umbilicus wide.

Genitalia ( Fig. 4D ). Specimens from Col d’Amos and Bogui-Col des Roussettes were examined. Penis narrow and long and slightly broadened near subterminal insertion of vas deferens. There are straight longitudinal pilasters inside penis. Penial retractor inserts terminally at penis and at diaphragm. Vas deferens divided in thin distal section running along penis towards atrium and thicker proximal section along vagina and free oviduct. Vagina shorter than free oviduct.The oviduct consists of a short narrower distal section and a broader and longer glandular proximal section. Reservoir of bursa copulatrix only slightly broadened.

REMARKS

I could not examine type specimens of Helix volutella Gassies, 1858 (not L. Pfeiffer, 1856) and Helix cabriti Gassies, 1863 from Balade. However, only D. vaysseti is known from this region of New Caledonia.The description and the measurements of H. volutella Gassies fit D. vaysseti . Thus, I consider this preoccupied name a synonym of D. vaysseti . Helix cabriti Gassies includes besides the specimens from Balade also specimens from the Île Art that belong to a different species that is treated in the following as D. cabriti .

There are two specimens of D. vaysseti from the northwest end of New Caledonia (Mandjelia and Le Cresson) which are 2.8 and 3.1 mm broad at 5 whorls, but have a weak callus and there are two specimens from Monéo which have a strong, detached callus, but which are only 2.3 mm broad at five whorls. These exceptions may be due to ancestral polymorphism, convergence or introgression between D. vaysseti and D. solidula .

Diplomphalus cabriti ( Gassies, 1863) ( Figs 9 ; 10A )

Helix cabriti Gassies, 1863: 21 (in part); type locality (here restricted): “Île Art”, New Caledonia. — Crosse 1867b: 315, pl. 11, fig. 2 (in part). — Gassies 1871: 38 (?). — Fischer 1873: 9, pl. 3, fig. 8, 9.

Diplomphalus cabriti – Crosse & Fischer 1872: 288. — Crosse & Fischer 1873: 22 (in part). — Tryon 1885: 113, pl. 25, figs 91, 92. — Kobelt 1904: 87, pl. 13, figs 21, 22 (in part). — Franc 1957: 176, pl. 23, fig. 233 (in part). — Schileyko 2000: 752, fig. 980.

Diplomphalus (Diplomphalus) cabriti – Crosse 1895: 173 (in part). — Wenz & Zilch 1960: 551, fig. 1926.

TYPE MATERIAL. — Île Art, lecto- and paralectotype ( NHMUK 1883.11.10.289, 290).

OTHER MATERIAL EXAMINED. — New Caledonia ( FMNH 36985; MNHN, among others voucher specimen of

Crosse [1867b: 315, pl. 11, fig. 2]); Île Art ( MNHN; RBINS).

DISTRIBUTION ( FIG. 9 ). — Diplomphalus cabriti is known only from the Île Art without more exact locality. A record from Pouébo in the northernmost part of the main island of New Caledonia ( Gassies 1871; Crosse & Fischer 1873) is probably erroneous or might refer to Diplomphalus vaysseti (see also D. montrouzieri ( Souverbie, 1858)) .

DIAGNOSIS. — Diplomphalus cabriti differs from all other Diplomphalus species in a larger shell (diameter: 8.2-9.0 mm v 4.4-7.9 mm in all other species).

DESCRIPTION

Shell ( Fig. 10A ; Table 1) biconcave; spire deeply sunken, with 8.75-9.75 whorls with a compressed keel at upper side and an edge at basal side; protoconch smooth; teleoconch with coarse, regular ribs (26-39 per quarter on upper side of body whorl) at upper and basal side that usually split into 2-3 finer ribs at outer side of whorls between upper and lower edge and microscopic spiral threads; corneous with a reticulate pattern of reddish-brown diagonal stripes; aperture narrow crescentic, slightly wider below than above; upper insertion of peristome distinctly descending towards aperture; peristome slightly expanded, not reflexed, slightly thickened; insertions of peristome connected by a weak callus which is thickened at its margin, but not detached from body whorl; aperture without lamellae or folds; umbilicus wide.

Genitalia unknown.

Radula. Fischer (1873) counted 16 about equally long, slender, unicuspid lateral teeth on each side. He did not find central teeth, but if they are as small as in D. mariei , he might have missed them.

REMARKS

Gassies (1863) included specimens from Balade probably belonging to Diplomphalus vaysseti (see above) as well as specimens from the Île Art in his Helix cabriti . All later descriptions and figures of D. cabriti refer to the species from the Île Art. I could not examine type specimens of H. cabriti from Balade. However, there are two specimens from the Île Art labelled as types of H. cabriti Gassies in the Natural History Museum in London (NHMUK 1883.11.10.289-290). I designate one of these specimens (the one glued at the basal side to the card board; measurements shell diameter: 9.1 mm, shell height: 4.2 mm) as lectotype of H. cabriti Gassies, 1863 to clarify the taxonomic status of the name and to preserve stability of nomenclature.

Diplomphalus cabriti is probably most closely related with D. montrouzieri , which is also larger than the Diplomphalus species from the main island of New Caledonia and which also has a callus which is thickened at its margin, but is not detached from the body whorl.

Diplomphalus montrouzieri ( Souverbie, 1858) ( Figs 9 ; 10B )

Helix montrouzieri Souverbie, 1858: 63 ; type locality: “Artensis insula”, New Caledonia. — Fischer 1858: 296, pl. 8, fig. 7. — Gassies 1863: 20, pl. 1, fig. 3. — Gassies 1871: 38.

Diplomphalus montrouzieri – Crosse & Fischer 1873: 23. — Tryon 1885: 113, pl. 25, fig. 90. — Kobelt 1904: 87, pl. 14, figs 1, 2. — Franc 1957: 177.

Diplomphalus (Diplomphalus) montrouzieri – Crosse 1895: 175.

TYPE MATERIAL. — Île Art, 3 syntypes ( MNHN).

OTHER MATERIAL EXAMINED. — New Caledonia ( FMNH 36983 , 36984 ; MNHN) ; Île Art ( MNHN, among others 3 syntypes of H. montrouzieri Souverbie ; RBINS; ZMH 79088) ; “Pouébo” ( MNHN); “Canala” ( RBINS).

DISTRIBUTION ( FIG. 9 ). — Diplomphalus montrouzieri is probably restricted to the Île Art. There is a sample from Pouébo in the northern part of the main island of New Caledonia (MNHN) from where D. montrouzieri and also D. cabriti have been recorded by Gassies (1871). However, neither of these species has been found in that region of the main island of New Caledonia for more than a century, although several expeditions have collected there. There is also a sample that is allegedly from Canala (RBINS), but this is almost certainly an error.

DIAGNOSIS. — Diplomphalus montrouzieri is larger than the Diplomphalus species from the main island of New Caledonia, but smaller than D. cabriti (diameter of D. montrouzieri : 6.7-7.9 mm; of D. cabriti : 8.2- 9.0 mm), from which it differs also in a whitish shell colour without brownish pattern and a weaker sculpture of the teleoconch.

DESCRIPTION

Shell ( Fig. 10B ; Table 1) biconcave; spire deeply sunken, with 8.0-8.50 whorls with a compressed edge at upper side and an edge at basal side; protoconch smooth; teleoconch with flat, regular ribs (21-31 per quarter on upper side of body whorl) at upper and basal side that usually split into 2-3 finer striae at outer side of whorls between upper and lower edge and microscopic spiral threads; whitish; aperture narrow crescentic; upper insertion of peristome distinctly descending towards aperture; peristome not expanded, not reflexed,not thickened; insertions of peristome connected by a weak callus thickened at its margin, but not detached from body whorl; aperture without lamellae or folds; umbilicus wide. Genitalia unknown.

Figures

FIG. 1. — Distribution of Diplomphalus mariei (Crosse, 1867) (5’ grid).

FIG. 2.— Diplomphalus spp.,shells:A, Diplomphalus mariei (Crosse,1867),New Caledonia:Koé (possible syntype of H.mariei, NHMUK 1883.11.10.842-844); B, Diplomphalus mariei, New Caledonia: Canala (syntype of H. seberti, MNHN); C, Diplomphalus mariei, New Caledonia (syntype of D. fischeri, MNHN 22960). Scale bar: 1.0 mm.

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. 7. — Distribution of Diplomphalus solidula Tryon, 1885 (•) and Diplomphalus vaysseti (Marie, 1871) (⚫).

FIG. 8.—Diplomphalus spp.,shells:A, Diplomphalus solidula Tryon,1885,New Caledonia:Baie du Sud (syntype,MNHN);B, Diplomphalus vaysseti (Marie, 1871), New Caledonia: Thiem (MNHN). Scale bar: 1.0 mm.

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

FIG. 10. — Diplomphalus spp. shells: A, Diplomphalus cabriti (Gassies, 1863), New Caledonia, Île Art (upper side and front view of lectotype and basal side of paralectotype BMHN 1883.11.10.289-290);B, Diplomphalus montrouzieri (Souverbie,1858),New Caledonia, Île Art (syntype, MNHN). Scale bar: 1.0 mm.