Gabbia vertiginosa ( Frauenfeld, 1862 )

Ponder, Winston F., 2003, Monograph of the Australian Bithyniidae (Caenogastropoda: Rissooidea), Zootaxa 230 (1), pp. 1-126 : 15-29

Gabbia vertiginosa ( Frauenfeld, 1862)

Bithynia vertiginosa Frauenfeld, 1862: 1152 . New Holland, ex Shuttleworth; Frauenfeld, 1865a: 527, pl. 8 (Holotype, NHMV, no number); Frauenfeld, 1865b: 659; Tate & Brazier, 1881: 563 (as a synonym of Bithynia australis [Tryon]).

Bithynia Schraderi Frauenfeld, 1862: 1153 . Cuming colln. Ex. Schrader, on the Novara, Sydney (2 syntypes, NHMV, no number; Frauenfeld, 1865a: 527, pl. 9; Frauenfeld, 1865b: 645; Tate and Brazier, 1881: 563 (as a synonym of Bithynia australis (Tryon)) .

Gabbia australis Tryon, 1865: 220 [Lectotype (chosen Baker, 1964: 171) ANSP, 27225, 3 paralectotypes ANSP, 375743; 1 probable paralectotype, AMS, C.110160. New South Wales, Wesley Newcomb, M.D.; Iredale, 1943: 206; Iredale, 1944: 116; Smith, 1992: 32; Ponder & DeKeyzer, 1998: 760, fig. 15.116B­E (B. head­foot, C. penis, D. operculum, E. radula).

Bithinia hyalina Brazier, 1875: 9 (Eastern Ck (Sydney), NSW), Syntypes AMS, C110159 (4), MMS A69 (6) ( Ponder & Stanbury, 1972: 45); Iredale, 1943: 206 (as synonym of G. australis Tryon ); Smith, 1992: 32 (as a synonym of G. australis Tryon ).

Bithinia vertiginosa ; Smith, 1882: 266

Bithinia Schraderi ; Smith, 1882: 267.

Gabbia australis suspecta Iredale, 1944: 116 , fig. 5 (part). Armidale, NSW. Syntypes AMS, C51675 (50+), AMS, C100600 (3), WAM 2229–69 (23) (fide Smith 1992: 33); Smith, 1992: 33 (as incertae sedis).

Material examined

Types: Holotype of B. vertiginosa , syntypes of B. schraderi , lectotype and paralectotypes of G. australis , syntypes of G. australis suspecta and B.hyalina .

Other material

Queensland: Wilsons Plains , near railway station, 27° 50’S, 152° 39’E, in pond, 1952 ( MV F54835 , 12 )

New South Wales: Wellingrove Ck, 25 km NW of Glen Innes, 4 km N of Wellingrove, 29° 35.920'S, 151° 34.170'E, weeds in backwater, 19 DEC 1972, G.Witten ( AMS C.308020, several); 10 km SE Glen Innes, Lambs Valley Rd , 29° 45.460'S, 151° 48.770'E, rain water ponds, 26 NOV 1972, G.Witten ( AMS C.308014, 15); 14 km S Glen Innes, Grahams Valley Rd , 29° 51.930'S, 151° 43.530'E, small overflow pond in Ck , 01 JAN 1973, G.Witten ( AMS C.308023, 1); 20 km S Glen Innes ­ Guyra, 2 km N Glencoe, Barley Field Lagoon , 29° 54.620'S, 151° 43.830'E, amongst weeds, 18 DEC 1972, G.Witten ( AMS C.308021, 20+); S of Wandsworth , Limestone Ck. , Tingha­Guyra Rd , 30° 4.050'S, 151° 31.030'E, 13 JAN 1972, G.Witten ( AMS C.307878, 1); 7 km S Ben Lomond, Reeves Rd , 30° 4.810'S, 151° 41.520'E, weedy pool in gully, 01 JAN 1973, G.Witten ( AMS C.308027, 16); 13 km ENE Guyra, Aberfoyle R, Wards Mistake Rd , 30° 11.490'S, 151° 46.560'E, weedy stream, shallow swampy stream, 18 DEC 1972, G.Witten ( AMS C.308013, 20+); 6 km ENE Guyra, tributary of Gara R, 30° 12.000'S, 151° 43.250'E, large overflow pond, and in stream, 18 DEC 1972, G.Witten ( AMS C.308017, 20+); Illaroo Ck , ca. 1 km SW of Wee Waa on Pillaga Rd, 30° 15.000'S, 149° 25.000'E, amongst grass & weeds along edge of pool, 17 SEP 1996, W.F.Ponder & A.Kornuishin ( AMS C.319907, 20+); Narrabri, 30° 19.800'S, 149° 46.700'E, 1887, C.T.Musson ( AMS C.307859, 7); same locality, 1940 ( QM MO57225 , 1 ) ; Sutton Gully, 40 km NW Armidale, near Longford, 30° 19.930'S, 151° 24.820'E, 23 JAN 1973, G.Witten & Gemmell ( AMS C.308024, 7); Gara R on Rockvale Rd , 30° 26.880'S, 151° 49.340'E, Stagnant pools, 03 OCT 1972, G.Witten ( AMS C.308029, 20+); Yarrowyck (= Yarrowick ), NW of Armidale, 30° 28.110'S, 151° 21.440'E, 1926, A.McKay ( AMS C.51673, 5); 1 km NE Brookside, NE Armidale , 30° 28.340'S, 151° 48.940'E, stagnant pools, 03 OCT 1972, G.Witten ( AMS C.308030, 16); Armidale , 30° 31.510'S, 151° 39.630'E, 1926, A.McKay ( AMS C.51672, 20+; AMS C.51675, 20+; AMS C.51688, 1; AMS C.100600, 3); same locality, 1926, B.Bradley ( AMS C.51752, 11); same locality, 1988 ( AMS C.307886, 2); 5 km E of Armidale, Grafton Rd , 30° 31.840'S, 151° 42.850'E, in dam, 22 OCT 1972, R. Simpson ( AMS C.308015, 20+); Tributary of Macleay R, Commissioners Water , near Armidale , 30° 32.430'S, 151° 43.690'E, in mud and gravel, 12 MAY 1944, H.F.Consett Davis ( AMS C.307852, 1); 5.5 km S Armidale ­ Kelly's Plains Rd, 30° 32.910'S, 151° 38.080'E, weedy pool, 09 NOV 1972, G.Witten ( AMS C.308025, 20+); SW of Armidale, S of Uralla on Uralla Rd , Dangars (= Uralla ) Lagoon , 30° 41.240'S, 151° 30.040'E, edge of lagoon, 10 APR 1973, R. Simpson ( AMS C.332523, 7); Gostwyck Stn , SE Uralla , 30° 41.550'S, 151° 35.200'E, 16 SEP 1940, L.Whitten ( AMS C.307865, 20+); 6 km E Gostwyck, 33 km S of Armidale, 30° 42.770'S, 151° 39.100'E, temporary weedy pond, 20 OCT 1972, G.Witten ( AMS C.308016, 20+); Frizzly Ck (= Frizzly Swamp ), 20 km S Uralla, 30° 49.400'S, 151° 32.500'E, weedy pools, 11 NOV 1972, G.Witten ( AMS C.308022, 20+); 13 km NW Walcha­Wollun, 30° 53.970'S, 151° 30.140'E, weedy pools, 11 NOV 1972, G.Witten ( AMS C.308019, 20+); 0.8 km N of Emu Ck, E of Walcha, 30° 56.220'S, 151° 56.220'E, weedy pool in spring, top of dam, 03 FEB 1972, G.Witten ( AMS C.332883, 14); Emu Ck , E of Walcha, 30° 56.570'S, 151° 42.340'E, under rock at edge of Ck , 03 FEB 1972, G.Witten ( AMS C.332885, 20+); MacDonald R, 5 km S Walcha Rd, 30° 59.550'S, 151° 23.000'E, weed bed of river ( Valisnen's ), 11 JAN 1973, G.Witten ( AMS C.308026, 1); Rocky Gully , 7.5 km S of Walcha, 31° 3.050'S, 151° 35.000'E, small stream, 11 JAN 1973, G.Witten ( AMS C.308028, 20+); Tamworth , 31° 6.120'S, 150° 55.490'E, 1891, C.T.Musson ( AMS C.307867, 8); Scone , 32° 3.000'S, 150° 52.000'E, 1941 ( AMS C.307899, 20+), same locality, J. Brazier ( ANSP, 27223, several); N of Riverstone, off Windsor Rd , 33° 38.700'S, 150° 51.300'E, 15 JUN 1980, M.Shea ( AMS C.307889, 1); Windsor Rd , Box Hill , 33° 39.720'S, 150° 52.650'E, in Ck , 1971, N.J.Campbell ( AMS C.307851, 15); South Hornsby , unnamed Ck , 33° 43.200's, 151° 6.000'e, 24 FEB 1975 ( AMS C.401250, 1); Eastern Ck , 33° 45.000'S, 150° 52.000'E, 1900 ( AMS C.307856, 16); Eastern Ck , Rooty Hill , 33° 46.000'S, 150° 50.000'E, 1875, J.Brazier ( AMS C.110159, 4; Macleay Mus. A. 69; AMS C.171073, 6); Rooty Hill , 33° 46.300'S, 150° 50.600'E, 1877 ( AMS C.307866, 3); Parramatta (and Eastern Ck ), 33° 47.500'S, 150° 57.000'E, 1877 ( AMS C.307853, 12); near Eastern Ck , on Great Western Highway , 33° 47.530'S, 150° 51.730'E, in small, sluggish creek, 09 OCT 1975, W.F.Ponder & P.H.Colman ( AMS C.412622, 20+); tributary of Eastern Ck on private rd to Wallgrove Quarry , off Old Wallgrove Rd , 33° 48.620'S, 150° 50.730'E, reeds, roots & substrate, 26 FEB 1997, A.C. Miller ( AMS C.203392, 20+); Parramatta , 33° 49.000'S, 151° 1.000'E, 1900 ( AMS C.307860, 6); same locality, JAN 1905, A. P. Schrader ( AMS C.307870, 11); Sydney W, Parramatta , 33° 49.000'S, 151° 1.000'E, in pond, 1912 ( AMS C.307874, 7); Mulgoa , 33° 50.000'S, 150° 39.000'E, in ponds, 1912 ( AMS C.307869, 20); Mulgoa Ck , Mulgoa , near bridge on Kings Hill Rd , 33° 49.950'S, 150° 39.490'E, in weeds, 17 APR 1988, G.A.Clark ( AMS C.332866, 20+; AMS C.307863, 20+); Littlefields Ck at Mulgoa Rd crossing, Mulgoa , 33° 50.000'S, 150° 39.200'E, 04 MAY 1980, M.Shea, O.L.Griffiths & C.Urquhart ( AMS C.307855, 23); Mulgoa , Mulgoa Ck at road crossing, 33° 50.000'S, 150° 40.000'E, 04 MAY 1980, M.Shea ( AMS C.346193, 20); same locality, FEB 1993, M.Shea ( AMS C.320195, 5); Kemps Ck , Kemps Ck ( Bonnyrigg ), off Elizabeth Drive , under bridge, 33° 52.970'S, 150° 48.030'E, 12 APR 1975, C. Wallace ( AMS C.332859, 20+); Lackey Rd Dam , St John's Park , Fairfield , W of Sydney, 33° 53.000'S, 150° 54.000'E, JAN 1956, Hamilton & Pearson ( AMS C.307875, 20+); Duncans Ck , S of Wallacia, 33° 54.010'S, 150° 38.440'E, 06 MAR 1975 ( AMS C.332890, 20+); Cabramatta Ck , SW Sydney , 33° 55.350'S, 150° 54.300'E, 1950 ( AMS C.307868, 6); Ingleburn , SW Sydney , 34° 0.000'S, 150° 52.000'E, 21 JAN 1941 ( AMS C.202843, 16); Ingleburn , Myrtle Ck , 34° 30.000'S, 149° 50.000'E, 24 FEB 1975 ( AMS C.401249, 16); Georges R near Ingleburn , 34° 0.500'S, 150° 53.230'E, NOV 1952, F. E. Allen ( AMS C.307871, 3); tributary of Bunbury Curran Ck , Ingleburn , 34° 59.840'S, 150° 52.080'E, 24 FEB 1975 ( AMS C.332871, 20+); Sydney , Blair Athol , approx 200m past junction of Mossberry & The Kraal Drive, 34° 3.867'S, 150° 47.833'E, small dry creek, 25 JUL 2000, S.A.Clark ( AMS C.401242, 6); Camden Park, 34° 5.430'S, 150° 43.070'E, 1912 ( AMS C.307854, 20+); Campbelltown, Menangle, 34° 7.700'S, 150° 44.700'E, waterhole, 28 JAN 1941 ( AMS C.381624, 16); Glenfield, unnamed creek, 33° 58.000'S, 150° 54.000'E, 24 FEB 1975 ( AMS C.401248, 2); Trib of Bargo R, ca. 4.1 km from Picton Rd on Menangle Rd , 34° 10.720'S, 150° 40.880'E, in algal mat & base of reeds & on substrate, 26 FEB 1997, A. C.Miller ( AMS C.352373, 20+); near intersection of Picton Rd & Menangle Rd, Maldon, 34° 11.510'S, 150° 37.930'E, edge of pond, 11 JUL 1995, M.V. Jones & S.M. Ridge ( AMS C.309414, 1).

Description

Shell ( Figs 1A , C­H; 2A­E, 3A­E) of moderate size (up to 7.4 mm in length), conic to ovate­conic, with up to 5 convex whorls. Protoconch of about 1.5 whorls, smooth except for traces of exceedingly fine spiral striae. Some specimens with 5­6 low, weak spiral ridges on last whorl (e.g., Fig. 2A ). Teleoconch smooth except for fine collabral growth lines; base evenly convex; umbilicus very small and narrow or closed in adults and juveniles. Aperture broadly ovate; peristome thin; outer lip slightly prosocline. Opaque to semi­translucent; periostracum thin to well­developed, pale yellowish­white to dark brown.

Dimensions. See Table 1 for dimensions of type material and Appendix, Table 29 , for summary shell dimensions and whorl counts.

Operculum ( Figs 4 A­E) typical of genus. Ovate, flat to very slightly concave, yellowish­white to brown, sometimes slightly translucent, concentric growth ridges mainly indistinct, a few very distinct; inner surface with muscle scar weakly pustulose to pitted.

Radula (Appendix Table 30 ; Fig. 5 A­F) typical of genus. Central teeth with 3­4 cusps on either side of median cusp which is about 1.5 longer than adjacent cusps and its base subequal to slightly wider; median cusp initially parallel­sided or very slightly tapering, distally tapering to sharp point. Face of central tooth with 3­4 pairs of cusps that extend just inside lateral margin forming denticulate ridge, inner pair much larger than others, large (about 0.2 total height of tooth); lateral margins straight to slightly concave, at about 50­60º; basal tongue narrow, long, prominent, usually with pointed end (sometimes rounded). Lateral teeth with cusp formula 2 + 1 + 3­4 (usually 3); with cutting edge about 0.35­0.47 length of lateral part of tooth; median cusp to about 1.5 length of adjacent cusps, pointed to rounded; upper edge of lateral part of tooth at about 50­65º to cutting edge, lateral edge straight to slightly concave. Inner marginal teeth with about 17­23 cusps, outer marginals with 10­18 small cusps.

Head­foot with dark grey to black snout, tentacles grey to unpigmented, dorsal foot and opercular lobe dark grey, base of penis pale grey. Mantle roof black with small round white blotches giving it a mottled appearance, uniformly black or grey in some. Mantle edge grey to unpigmented. Visceral coil usually black dorsally.

Anatomy. Gill ( Fig. 6A, E ) with apices from very close to right edge in posterior two thirds, usually apices up to about third gill width in anterior third, sometimes up to about third gill width from right along entire gill; 42­62 filaments (n=7). Osphradium opposite middle of gill to slightly posterior of middle. Penis ( Fig. 7I, J ) with accessory lobe from about two thirds length of penial lobe to subequal in length, end of accessory lobe swollen, sucker­like;accessory gland long. Pallial oviduct with capsule gland narrower than, and slightly longer to nearly twice as long as, albumen gland. Bursa copulatrix on inner ventral wall of capsule gland, about quarter to nearly third height of capsule gland, extending to posterior pallial wall ( Fig. 8A ) (AMS C.332866, AMS C.203392, AMS C.352373, AMS C.332885, AMS C.308028).

Distribution ( Fig. 9 ) and habitat. South east Queensland to mid NSW (south of Sydney), with most records from western Sydney and the New England tablelands, including the western slopes as far west as the vicinity of Narrabri (149º 46’E). Lives in mud in shallow water in ponds, farm dams, swamps and sluggish creeks, including temporary water bodies.

Remarks

The long established name Gabbia australis Tryon is, unfortunately, superseded by two Frauenfeld names. These two names were listed by E. A. Smith (1882), Tate and Brazier (1881: 563) and Tate (1896: 210­211). Iredale (1943), surprisingly, did not list or comment on these names, and they have not appeared in Australian literature since, including the catalogue of non­marine molluscs by Smith (1992). Tate and Brazier (1881) listed these names as dating from Frauenfeld 1865, although they cited the page numbers in the 1862 paper. Tate (1896: 210­211) noted that “Mr Brazier has communicated to me his opinion that B. schraderi, Fld. , and B. australis are one and the same; but as Frauenfeld's diagnosis, … 1862, was unaccompanied by figures and without comparison with any other species, except his B. vertiginosa , to which the same criticisms are applicable, and which may after all be only an elate form, of a composite species, the question of priority in respect to exact definition may reasonably be raised. Frauenfeld did not figure his two species till late in 1865, whereas the publication of Tryon's species is dated July, 1865.” Both species names were, however, validly introduced in 1862, before any other Australian bithyniids were named. Examination of the type material suggests that both species are conspecific with G. australis Tryon.

The populations in the vicinity of Armidale (New England district) were separated as distinct by Iredale (1944: 116) because “the Sydney shell, measuring about a quarter of an inch [= 6.3 mm] in height and one­sixth [4.2 mm] in breath, is smaller and narrower than the form figured from Armidale, which may be called Gabbia australis suspecta , subsp. nov., the type measuring 7 mm. by 5 mm.” [width/length ratios both 0.7]. Despite Iredale's subterfuge of resorting to different units of measurement, the differences are insignificant (see also Fig. 10A ). Iredale’s observation that the New England form is broader than the Sydney form is generally true but there is no clear­cut separation, even within the type material of suspecta (see Fig. 1C, D ). The difference is also reflected when the measurement data is subjected to a discriminant function analysis, the specimens from the two areas being correctly classified with only 73% success. The Sydney and New England populations are also separated by a gap in the distribution records. There are no recent records from the Hunter Valley and no records between there and northern and western Sydney. Whether this gap is a collecting artefact or real is uncertain, as suitable habitats for bithyniids have not been particularly well sampled in the intervening area. While the differences between the Sydney and New England forms are not judged significant here, this conclusion requires further testing with molecular data.

Specimens on the western slopes of the divide in the New England area are sometimes difficult to separate from G. campicola n.sp. but the radulae of three such populations (AMS C.319907, AMS C.308017, AMS C.308020) are characteristic of G. vertiginosa . Two measured western populations near Guyra differ slightly from the other populations (Appendix, Table 29 ).

One lot (AMS C.332890) from western Sydney is atypical and not included in the above description. The shell ( Fig. 2E , 3 C­E) has minute spiral wrinkles and, while the radula is similar in shape to other material of G. vertiginosa examined, it has different cusp details: central teeth with 2­3 basal cusps (instead of 3­4), lateral teeth with 8­9 cusps (instead of 6­8); and the inner and outer marginal teeth with 15­21 (cf. 17­27) and 7­13 (cf. 10­18) cusps respectively.

Bithinia australis Smith, 1882 was included in the synonymy of G. australis Tryon by Tate (1896) and Smith (1992), along with the replacement names, B. smithii Tate, 1882 and B. tryoni Smith 1887 , although Iredale (1943) correctly listed smithii as a separate species (as Gabbia smithii ).

Smith (1992) included G. centralia Iredale, 1943 as a synonym of G. australis Tryon but it is here considered a synonym of G. iredalei Cotton, 1942 as indicated by Cotton (1943).

This rather variable taxon (see Fig. 2 A­E) has a smooth ovate­conic to conic shell, with convex whorls. A few specimens have weak spiral ridges on the last whorl and this character is variably developed within single samples, with other specimens being completely smooth. Several species described below have a similar shell to G. vertiginosa and are differentiated in the remarks under those taxa.

The head­foot, penis, operculum and radula have been figured by Ponder & DeKeyzer (1998, fig. 15.116B­E). McKay (1926) found that 25% of a laboratory population survived for more than 200 days out of water but, surprisingly, no other published information on the ecology and biology of this species is available.

Figures

FIGURE 1. Shells of type specimens: A, Bithynia vertiginosa Frauenfeld 1862, holotype, NHMV, shell length 6.79 mm; B, Gabbia iredalei Cotton 1942, holotype, SAM, D14098, shell length 6.97 mm; C, Gabbia australis suspecta Iredale 1944, syntype, AMS, C.51675, shell length 6.54 mm; D, Gabbia australis suspecta Iredale 1944, syntype, AMS, C.100600, shell length 4.65 mm; E; Bithynia schraderi Frauenfeld 1862, holotype, NHMV, shell length 6.46 mm; F, Bithinia hyalina Brazier 1875, syntype, AMS, C.110159, shell length 4.98 mm; G, Bithinia hyalina Brazier 1875, syntype, MMS A69, shell length 6.63 mm; H, Gabbia australis Tryon, 1865, probable paralectotype, AMS, C.110160, shell length 5.43 mm; I, Gabbia affinis Smith 1882, topotype, AMS, C.2515, shell length 4.44 mm; J, Bithinia australis Smith, 1882 (= Gabbia smithii Tate 1882), lectotype, BMNH, 197748, shell length 3.20 mm; K, Gabbia microcosta n.sp., holotype, AMS, C.417677, shell length, 8.51 mm; L, Gabbia spiralis, n. sp., holotype, AMS, C.417682, shell length 4.56 mm.

FIGURE 2. Shells: A – E, Gabbia vertiginosa, A, AMS, C.203392, B ­ D, AMS, C.308015, E, AMS, C.332890; F, Gabbia iredalei, AMS, C.337418; G – K, Gabbia campicola, G, AMS, C.344345, H, holotype, C.417664, I, paratype, C.332829, J, K, MV, F.54869; L­N, Gabbia kendricki, L, holotype, WAM S10877, M,N, paratypes, AMS C.203378; Scales: A – E, L­N, 500 m, F, 2 mm, G – K, 1mm.

FIGURE 3.Protoconchs and microsculpure: A – E, Gabbia vertiginosa, A, B, AMS, C.308015, C – E, AMS, C.332890; F – I, Gabbia campicola, F – H, paratype, AMS, C.332829, I, AMS, C.318702; J, Gabbia kendricki, paratype, AMS, C.203378; K, Gabbia pallidula, paratype, AMS, C.308007; L, M, Gabbia napierensis, paratype, AMS, C.337372; N, O, Gabbia rotunda, paratype, AMS, C.400134; A, B, F ­ J, L ­ N, protoconch, C ­ E, K, O, microsculpture; Scales: A ­ B, F ­ J, L, 100 m, C ­ D, N, 200 m, E, K, O, 20 m, M, 500 m.

FIGURE 4. Opercula: A ­ E, Gabbia vertiginosa, A, B, AMS, C.203392, C, D, AMS, C.308015, E, AMS, C.332890; F, Gabbia iredalei, MV F.54870; G ­ I, Gabbia campicola, paratype, AMS, C.332829; J ­ L, Gabbia kendricki, AMS, C.337372; A, C, E ­ H, J, K, outer side; B, D, I, L, inner side; Scales: 500 m.

FIGURE 5. Radula: A – F, Gabbia vertiginosa, A, B, F, AMS, C.203392, C, AMS, C.332890, D, E, AMS, C.308015; G, H, Gabbia iredalei, MV, F.54870; A, C, D, H, central teeth, B, half rows of teeth, E, marginal teeth and lateral teeth, F, lateral teeth, G, half rows of teeth and second row of lateral teeth; Scales: 20 m.

FIGURE 6. Gills and osphradia. A, E – Gabbia vertiginosa, A, AMS, C.203392; E, AMS, C.308028; B – Gabbia beecheyi, AMS, C.332844; C – Gabbia fontana, AMS, C.307903; D – Gabbia rotunda, AMS, C.400134; F – Gabbia adusta, AMS, C.203394; G – Gabbia smithii AMS, C.322309; H – Gabbia kessneri, AMS, C.351073. Scales: 500 m. os ­ osphradium.

FIGURE 7. Penis and accessory gland. A, D – Gabbia campicola, A, ventral view, C.332829, D, dorsal view, USNM, 803665; B – Gabbia rotunda, ventral view, AMS, C.400134; C – Gabbia davisi, ventral view, AMS, C.417617; E – Gabbia beecheyi, ventral view, AMS, C.332843; F, G – Gabbia fontana, dorsal view, AMS, C.380863; H – Gabbia spiralis, dorsal view, AMS, C.331849; I, J – Gabbia vertiginosa, dorsal view, AMS, C.203392, I, enlargement of distal end of accessory lobe; K – Gabbia adusta, dorsal view, AMS, C.203394. Scales: 500 m.

FIGURE 8. Pallial oviducts, viewed from left side. A, Gabbia vertiginosa, AMS, C.332866; B, Gabbia smithii, AMS, C.322309; C, Gabbia kessneri, AMS, C.322308. Scales: 500 m.

FIGURE 9. Distribution of Gabbia vertiginosa (o), G. iredalei (), G. cf. iredalei (), G. campicola (), G. fontana (), G. pallidula (☆), G. davisi () and G. rotunda (

FIGURE 10. A ­ Plot of the shell width/shell length (SWSH) against length/number of teleoconch whorls (SHTW) for two geographic sets of samples of G. vertiginosa. x – Sydney area; O – New England area. B ­ D ­ Plots of the canonical scores obtained from a discriminant function analysis using all shell measurements and whorl counts. B, x – G. iredalei; O – G. campicola; + ­ G. vertiginosa. C, x – G. aff. vertiginosa; O – G. campicola; + ­ G. iredalei; ­ G. aff. iredalei; ­ G. vertiginosa. D, x – G. davisi; O – G. campicola; + ­ G. fontana; ­ G. pallidula; ­ G. rotunda;