Siphonaria viridis Quoy & Gaimard, 1833

Siphonaria viridis Quoy & Gaimard, 1833 View in CoL

( Figs 22 View FIGURE 22 , 23 View FIGURE 23 , 24 View FIGURE 24 )

Siphonaria viridis Quoy & Gaimard 1833: 332 View in CoL , pl. 25, figs 30–31 (type locality: Amboine, aussi la Nouvelle-Guinée [ Ambon, Maluku Islands, Indonesia, and New Guinea]).— Lamarck 1836: 156; 1839: 206; Catlow & Reeve 1845: 100; H. Adams & A. Adams 1855 (in 1853–1858): 271; Hanley 1858b: 561; H. Adams & A. Adams 1863: 271; Paetel 1889: 430; White & Dayrat 2012: 69.

Siphonaria sipho View in CoL — Hedley 1909: 369 (not S. sipho Sowerby I, 1823 View in CoL ).

Siphonaria (Siphonaria) sipho View in CoL — Adam & Leloup 1939: 7, pl. 2, fig. 1a–d, text-fig. 1a–c (not S. sipho Sowerby I, 1823 View in CoL ).

Siphonaria punctata Quoy & Gaimard 1833: 342 View in CoL , pl. 25, fig. 13–14 (type locality: ‘On la trouve sur les rochers du port Louis de Île-de-France’ [on rocks, Port Louis, Mauritius]).— Lamarck 1836: 559; 1839: 205; Catlow & Reeve 1845: 100; H. Adams & A. Adams 1855 (in 1853–1858): 271; 1863: 271; Martens 1880: 310; Paetel 1889: 429; Hubendick 1943: 47; Michel 1974: 274; Galindo 1977: 416; White & Dayrat 2012: 67.

Parellsiphon zanda Iredale 1940 View in CoL ; 438, fig. 7–8 (type locality: Low Isles, North Queensland, [ Australia]).— Hubendick 1945: 29; Morrison 1972: 57; White & Dayrat 2012: 69.

Parellsiphon promptus Iredale 1940: 438 View in CoL , fig. 24, 25 (type locality: Northwest Is, Capricorn Group [Qld, Australia]).— Hubendick 1946: 30; Morrison 1972: 57; White & Dayrat 2012: 67.

Legosiphon optivus Iredale 1940: 440 View in CoL , fig. 26, 27 (type locality: Magnetic Island, Queensland [ Australia]).— Hubendick 1955: 7; Short & Potter 1987: 122; White & Dayrat 2012: 65.

Legosiphon mirificus Iredale 1940: 440 View in CoL , fig. 28, 29 (type locality: Magnetic Island, near Townsville, Queensland [ Australia]).— White & Dayrat 2012: 66.

Legosiphon densatus Iredale 1940: 441 View in CoL , fig. 18–19 (type locality: Port Douglas, North Queensland, [ Australia]).— Hubendick 1946: 47; White & Dayrat 2012: 62.

Siphonaria (Siphonaria) optivus View in CoL — Hubendick 1946: 47.

Siphonaria (Siphonaria) laciniosa View in CoL — Hubendick 1946: 47, pl. 3, fig. 18 (in part); 1955: 7 (not S. laciniosa ( Linnaeus, 1758)) View in CoL .

Siphonaria (Siphonaria) stellata View in CoL — Hubendick 1946: 48, pl. 3, fig. 22 (not S. stellata ( Helbling, 1779)) View in CoL .

Siphonaria (Siphonaria) laciniosa var. sipho View in CoL — Hubendick 1946: 52, pl. 4, fig. 8; 1955: 7 (not S. sipho Sowerby I, 1823 View in CoL ).

Siphonaria (Siphonaria) zanda View in CoL — Hubendick 1946: 52, pl. 4, fig. 8 – 11.

Siphonaria australis View in CoL — Hubendick 1955: 7 (not S. australis Quoy & Gaimard, 1833 View in CoL ).

Siphonaria laciniosa View in CoL — Drivas & Jay 1988: 132, pl. 51, fig. 18 (not S. laciniosa (Linneaus, 1758)) View in CoL .

Siphonaria (Mestosiphon) laciniosa View in CoL — Morrison 1972: 57 (not S. laciniosa ( Linnaeus, 1758)) View in CoL .

Siphonaria laciniosa View in CoL — Short & Potter 1987: 122, pl. 60, fig. 7; Wells & Bryce 1995: 113; 1996: 63; Bryce 1997: 55; Tan & Woo 2010: 61; Tan & Yeo 2010: 294; Willan et al. 2015: 330 (not S. laciniosa ( Linnaeus, 1758)) View in CoL .

Siphonaria javanica View in CoL — Tan & Chou 2000: 116, fig 116; 2010: 61 (not S. javanica ( Lamarck, 1819)) View in CoL .

Siphonaria ‘laciniosa View in CoL group, unit 25’— Dayrat et al. 2014: 261, fig 4K–R (in part).

Material examined. Type material. Lectotype of Siphonaria viridis Quoy & Gaimard, 1833 , present designation, from ‘rade d’Amboine , aussi la Nouvelle-Guinée’ [on rocks, Amboina] ( MNHN-IM-2000-35958 ; Fig. 22A View FIGURE 22 ). Three paralectotypes MNHN-IM-2000-5042 , same data as lectotype. Holotype of Parellsiphon zanda Iredale, 1940 AM C.l03706 (from GBR and Michaelmas Cay , N Qld, [ Australia]; coll. May 1926; Fig. 22B View FIGURE 22 ). Lectotype of Siphonaria punctata Quoy & Gaimard, 1833 , present designation, from Île-de-France [ Mauritius, Indian Ocean ] ( MNHN-IM-2000-35957 , Fig. 23A View FIGURE 23 ). Two paralectotypes, same data as lectotype ( MNHN-IM-2000-5053 ). Syntype of Parellisiphon promptus Iredale 1940 AM C.103707 (from North West Island [23°18’S 151°42’E], Capricorn Group, [Qld, Australia]; coll. May 1931; Fig. 22C View FIGURE 22 ). GoogleMaps Holotype of Legosiphon densatus Iredale, 1940 AM C.103716 (from Port Douglas , N Qld, [ Australia]. Holotype of Legosiphon optivus Iredale, 1940 AM C.103719 (from Magnetic Island , Qld, [ Australia]; coll. A.F. Basset Hull, May 1924; Fig. 22H View FIGURE 22 ). Seventeen probable paratypes of Legosiphon optivus Iredale, 1940 AM C. 153469 , same data.

Syntype of Legosiphon mirificus Iredale, 1940 AM C.103718 (from Magnetic Island , near Townsville, Qld, [ Australia]; coll. A.F. Basset Hull, May 1924; Fig. 22G View FIGURE 22 ). Five probable paratypes of Legosiphon mirificus Iredale, 1940 same data as probable holotype, AM C.153362 ).

Probable holotype of Legosiphon densatus Iredale, 1940 from Port Douglas , N Qld, [ Australia]; coll. Nov 1929, ( AM C.103717 , Fig. 22D View FIGURE 22 ). Two questionable paratypes, same locality data, Nov 1928 ( AM C.106998 ) .

Other, non-type material. Mauritius: Trou-auxBiches, 20°02.488’S, 57°32.353’E, MRU04-1 ( AM C.585972 20+p, C.585834 p [M246], C.585835 p [M247], C.585836 p [M248]) GoogleMaps . PNG: New Ireland, NW side of Big Nusa Island, 02°34.1’S, 150°46.7’E KM12 ( MNHN IM-2013-55336 p [M534]); GoogleMaps Lemus Island, 02°38’S, 150°37.5’E KM24 (IM-2013-53728 p [M533]; IM-2013- 53874 p [M530]); GoogleMaps Ta Island , 02°41.6’S, 150°44.3’E KM22 ( MNHN IM-2013-51004 p [M537]; IM-2013- 55767 p [M536]; IM-2013- 55768 p [M539]; IM-2013- 55765 p [M540]; IM-2013- 55766 p [M541]; IM-2013- 55770 p [M542]; IM-2013- 55769 p [M543]; IM-2013- 50993 p [M544]); GoogleMaps Rempi Area , S Dumduman Is., 05°00,2’S, 145°47,6’E PM12 ( MNHN IM-2013-11999 p [M561]); GoogleMaps Riwo waters, 05°08.9’S, 145°48.2’E PM40 ( MNHN IM-2013-15249 p [M553]); GoogleMaps Biliau Island , 05°11.8’S, 145°48.2’E, PM38 ( MNHN IM-2013-14828 p [M549], PM39 (IM-2013-15190 p [M556]) GoogleMaps . Australia, Qld: Cape York Peninsula, Bamaga , Umagico , 10°53.125’S, 142°20.799’E, Q50-1 ( AM C.585181 [M179], C.585599 4p, C.585180 p [M104], C.585182 p [M433, SK140 ( RS), C.595938 p [SK539], C.595939 p [SK540], C.585184 p [SK352], C.585185 p [SK353]) GoogleMaps . Bathurst Head, 14°15.912’S, 144°11.598’E, Q41-2 ( AM C.585973 10p); GoogleMaps S of Bathurst Head, 14°17.583’S, 144°11.845’E, Q41-1 ( AM C.585948 4p); GoogleMaps Lizard Island, 14°40.908’S, 145°27.007’E,Q40-1( AM C.585642 5p); GoogleMaps Cape Kimberley , 16°16.535’S, 145°28.737’E, Q35-1 ( AM C.585903 2p, C.585173 p [M084], C.585174 p [M085]); GoogleMaps Low Isles , 16°23.085’S, 145°33.596’E, Q34-1 ( AM C.585384 10p, C.585161 p [M137], C.585162 p [M138], C.585163 p [M139], C.585165 p [M432, SK137]); GoogleMaps Port Douglas , 16°28.697’S, 145°27.859’E, Q33-2 ( AM C.585962 6p, C.585963 5p, C.585157 p [SK217], C.585159 p [SK219], C.585871 p [M131, SK218], C.585872 p [M133]); GoogleMaps Bingil Bay , E of El Arish, 17°49.563’S 146°06.131’E ( AM C.420154 2d). GoogleMaps Magnetic Is., Balding Bay , 19°06.651’S, 146°52.260’E, Q27-1 ( AM C.585904 15p), GoogleMaps Horseshoe Bay , 19°06.755’S, 146°51.875’E, Q27-2 ( AM C.585900 6p), GoogleMaps Geoffrey Bay , 19°09.142’S, 146°52.125’E, Q27- 4 ( AM C.585902 7p C.585533 d [R4108], C.585869 p [M482], C.585870 p [M483]); GoogleMaps Rocky Bay , 19°10.43’S, 146°50.73’E ( AM C.459332 1d) GoogleMaps . Hamilton Is., Catseye Bay , 20°20.831’S, 148°58.002’E, Q18-1 ( AM C.585463 15p) GoogleMaps . NT: N Turtle Beach , 12°18.816’S, 136°55.930’E NT04-1 ( AM C.585069 p [M086], C.585070 p [M148], C.585071 p [M149], C.585072 p [SK079], C.585079 p [SK077]) GoogleMaps . Nhulunbuy, Cape Wirawawoi, 12°09.513’S, 136°46.904’E NT05-1A ( AM C.585594 4p), GoogleMaps East Woody Islet 12°09.695’S, 136°45.075’E NT05-2 ( AM C.585632 5p, C.585078 p [M462, SK196]) GoogleMaps . Cobourg Peninsula, Kuper Pt 3, 11°10.688’S, 132°13.711’E NT21- 7 ( AM C.585390 10+p, C.585086 p [M093], C.585087 p [M142]), GoogleMaps Kuper Pt 2, 11°10.877’S, 132°13.554’E NT21-6 ( AM C.585084 d [M035], C.585085 p [M150]), GoogleMaps Smith Pt , 11°07.360’S, 132°08.134’E NT21-2 ( AM C.585634 5p), GoogleMaps Smith Pt 2, 11°07.466’S, 132°08.538’E NT21-3 ( AM C.585081 p [M463, SK198], C.585317 p [M034]); GoogleMaps Sandy Is Pt , 11°07.862’S, 132°11.187’E NT21- 1 ( AM C.585468 15+p, C.585080 p [M023], C.585842 p [M095]) GoogleMaps . Cox Peninsula, 12°24.824’S, 130°40.921’E NT25-1 ( AM C.585407 10+p); GoogleMaps Luxmore Hd, Melville Is , 11°20.639’S, 130°23.149’E NT24-1 ( AM C.585595 4p) GoogleMaps . WA: Caffarelli Is, 16°01.991’S, 123°18.625’E, WA19-1 ( AM C.584739 10+p, C.584659 p [M465, SK200], C.584660 p [M466, SK201], C.584661 p [SK290], C.584662 p [SK291], C.584784 p [SK221], C.585297 p [SK220],C.585298 p [SK360]); GoogleMaps Conilurus Is, 16°08.875’S, 123°35.234’E, WA18-1 ( AM C.585654 5p); GoogleMaps Catamaran Bay , 16°27.622’S, 123°00.242’E, WA22-3 ( AM C.584663 p [M026]); GoogleMaps Emeriau Point Middle Lagoon , 16°46.351’S, 122°34.200’E, WA23-1 ( AM C.584674 d [M396]; C.585884 d [M393]); GoogleMaps Broome , between Crab Creek and Broome, 17°58’S, 122°14’E ( WAM S76939 11p, p [SK065]); GoogleMaps Cape Latouche Treville nr Gourdon Bay , 18°27.101’S, 121°48.911’E, WA27-2 ( AM C.585795 20p, C.584675 p [SK149], C.585306 p [M066], C.585307 p [M067]); GoogleMaps Hearson Cove, Dampier, 20°38.079’S, 116°48.031’E, WA33-2 ( AM C.585309 p [SK064]); GoogleMaps Gnoorea Point 2 20°50.333’S, 116°20.825’E, WA36- 2 ( AM C.585885 d (M105)); GoogleMaps Tantabiddi, 21°54.739’S, 113°58.706’E, WA42-1 ( AM C.584676 p [M205]; C.585886 p [M206]) GoogleMaps . Timor-Leste: Dolokoan Beach , N of Dili, 8°31.424’S, 125°37.091’E TL01-1 ( AM C.585745 10+p, C.584796 p [M478, SK285], C.584821 p [SK299], C.584822 p [SK300], C.585388 p [SK558], C.585880 p [M442], C.585881 p [M443], C.585882 p [M444], C.585883 p [M450], C.595948 p [SK563]) GoogleMaps . Indonesia, Bali: Tanah Lot IND03 8°37.25967′S, 115°5.22967’E ( ZRC.MOL.24913 p [M473]) GoogleMaps . Singapore: St Johns Island, Peninsula Lokos 01°12.824’N, 103°51.076’E SI04-1 ( AM C.585224 p [M324], C.585225 p [M325]); GoogleMaps Lazarus Island channel headland, 1°13.085’N, 103°51.429’E SI04-4 ( AM C.585604 10p, C.585164 p [SK166], C.585243 p [M330], C.585244 p [SK167],C.585245 p [M329], C.585246 p [M331], C.585486 p [M336]); GoogleMaps Lazarus Island causeway, 01°13.288, 103°51.195’E SI04-3 ( AM C.585982 4p, C.585240 p [M328], C.585241 p [M333], C.585242 p [SK143]); GoogleMaps Lazarus Island , 01°13.355’N, 103°51.148’E SI04-2 ( AM C.585228 p [SK184]. GoogleMaps Malaysia: Palau Tioman 2°49′N, 104°11′E ZRC 1999-1781 7p, ZRC. MOL.24897 p [SK374], ZRC.MOL.24898 p [SK373]) GoogleMaps .

Taxonomic remarks. The lectotype of S. viridis is designated herein for the stabilisation of the name and to ensure the unambiguous identity of this taxon (Art. 74.1 of the Code). In addition, we designate the syntype of S. punctata with the clearest external sculpture ( Fig. 23A View FIGURE 23 ) as the lectotype of S. punctata for the stabilisation of the name (Art. 74.1 of the Code). The labels associated with the type specimens give ‘Île-de-France’ [ Mauritius].

Paetel (1889: 429) listed S. punctata ‘Quoy. I. Maurit. ’ as an accepted species. However, Reeve (1856), Hanley (1858b: 152) and Hutton (1880: 36) treated S. punctata as a synonym of S. sipho . Finally, Hubendick (1946: 47) listed S. punctata as a synonym of S. laciniosa . We recognise S. punctata as a synonym of S. viridis mainly based on genetic evidence. We found that topotypic specimens that closely match the shell morphology of the types fall within unit 25 ( Fig. 3 View FIGURE 3 : genetic vouchers M246–M248 from Mauritius) and exhibit morphological and anatomical features that are consistent with that of S. viridis .

The type locality of P. zanda given on the specimen label of the types (‘GBR and Michaelmas Cay, N Qld’ [ Australia]) differs from that given in the original description (‘Low Isles, N Qld’). The original descriptions of P. zanda and P. promptus each appear to be based on a single specimen. Iredale (1940: 438) referred to ‘type’ in the original descriptions of P. zanda , L. densatus and L. optivus but not in that of L. mirificus nor P. promptus . Therefore, we consider the single type specimens of P. zanda , L. densatus , and L. optivus as holotypes, but the types of L. mirificus and P. promptus as syntypes. No additional types are known to exist.

Hubendick (1946: 47) incorrectly considered S. viridis , L. optivus and L. densatus as synonyms of S. laciniosa based on shell colouration and shape. The interpretation of S. zanda in Hubendick (1946: 52) is likely based on a misidentification. While reference to the original designation is correct, the specimens examined and figured are from the Java Sea and Madagascar ( Hubendick 1946: pl. 4, figs 8–11) and clearly differ from the type ( Fig. 22B View FIGURE 22 ) (refer to Comparative remarks). Hubendick (1946: 53) incorrectly considered L. mirificus as a possible synonym of ‘ S. ferruginea’ (= S. plana ). The specimens figured in Hubendick (1946: pl. 4, fig. 16–19) do not resemble the type of L. mirificus . Morrison (1972: 56–58) synonymized ‘ Parellsiphon zanda ’ and ‘ P. promptus ’, with S. laciniosa based on similarities in shell shape and ‘common reproductive development’. These synonymies are rejected herein based on examination of type specimens and comparative morpho-anatomy.

Our delineation of this species is based on comparative analyses of the morpho-anatomy and mitochondrial genetics of freshly collected topotypes of all synonymized taxa and geographic series of additional specimens (Tables S1–2).

External morphology ( Figs 22P View FIGURE 22 , 23D View FIGURE 23 ). Foot sole, foot wall, pneumostome lobe and cephalic folds evenly grey or cream in colour, darker to centre of foot sole, paler to foot edge, cephalic folds cream to mouth; irregular black blotches cover all but foot sole, concentrated to centre of cephalic folds; mantle narrow than foot wall, evenly grey, edge thickened, with white band, lobed; pneumostome lobe large, under mantle.

Shell ( Figs 22–23 View FIGURE 22 View FIGURE 23 ; Table S9). Small to medium sized (max sl mean = 13.8 mm, SD = 3.6 mm, n = 21), elongate ovate; height tall; medium thickness; apex offset weakly posterior and left (frequently eroded), apical sides weakly concave, protoconch direction homostrophic (n = 6; Fig. 22T, W View FIGURE 22 ), shell whorl dextral; growth striae prominent, irregular, uneven; rib count (mean = 37, SD = 7.6, n = 21), primary ribs prominent, white, protrude slightly beyond shell edge, often wider than rib interstices, ridge edge rounded,fused pair highlight siphonal ridge;few secondary ribs, 0–3 secondary ribs between anterior primary ribs, dark brown/black radial bands in rib interstices overlaying interstices and secondary ribs; shell edge fragile, weakly scalloped and corrugated at primary rib end. Interior shell lip to margin dark brown and white, white rays align on shell margin under furrowed primary/secondary ribs, dual brown rays aligning under interstices extend from lip over margin to merge into a single brown ray to evenly brown spatula; siphonal groove distinct furrow; ADM scar distinct, CMS straight. Growth thickening and whitening of the shell lip, with retention of axial brown markings, is common in larger specimens. The holotype specimen is an example of shell thickening.

Reproductive system ( Fig. 24 View FIGURE 24 ; n = 21). Positioned within right side of coelom, against foot wall on foot muscle, under the respiratory cavity; epiphallic parts positioned between BM and RAM. GA small, with singular GP through foot wall; AO very large, wide, bluntly pointed, joined to upper GA, muscle attachment at side; ED elongated, thickened, centrally bent, joins to lower side of GA; GA, AO, ED all white muscular fibrous tissue; EG large, soft whitish tissue, slightly folded, joins ED; single narrow flagellum (F1), similar length and width to ED, appears as an extension of ED. BD and CD connect in opposing directions into GA between ED join and GP, CD join is bulbous, both ducts long straight smooth whitish, pass together on outer side of RAM ( BD over thicker CD) into soft white folded tissues of MG; BD long narrow with prominent distal loop with MA to inner anterior foot wall, bent and twisted before BC; CD long, wider than BD; CD connecting to MG ducts, BC embedded in folds close to embedded blackish SV; BC relatively small bulbous, thin whitish translucent test, 2 SPM in BC of topotypic specimen ( AM C.585165 Q34- 1 [M432, SK137]); MG / AG complex relatively large; HD short narrow coiled, links ducts in soft white folded tissues of AG to yellowish granulated HG; AG / MG larger than HG, sides match curvature of inner foot wall.

Spermatophore ( Figs 24B, D, F, I View FIGURE 24 ). Thread-like; head section (head length = 9.74 mm, head width = 94.6 μm, n = 1, flagellum incomplete) cylindrical, bulbous, bent, rounded tip, tapers to flagellum; test thin, smooth, featureless, translucent encasing a white opaque central core; a short tapering section merges head to filamentous flagellum; head section wider than translucent flagellum (complete flagellum unavailable). We found two SPMs tightly coiled in brown gelatinous mass in bursa [M432, SK137], two SPM coiled, embedded in white gelatinous mass in each [SK079, SK077], a single SPM in white gelatinous mass in one bursa [SK149].

Radula. Dentition formula: 20-25:1:25-20 ( Adam & Leloup, 1939: 8, as ‘ S. sipho ’), 40:1:40 ( Hubendick 1946: 47).

Comparativeremarks. Inourmolecularphylogenetic tree ( Figs 1–4 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 ), Siphonaria viridis ( laciniosa group, unit 25) is closely related to S. umagicoensis sp. nov. and S. punctata . These species are separated from each other by average genetic p-distances in COI of 6.5% to 8.1%. All three species together form a well-differentiated clade. Sequences from Sulawesi and Bali clustering within this clade and attributed to “unit 25” by Dayrat et al. (2014) are of uncertain identity and require further scrutiny for lack of morpho-anatomical study. Siphonaria viridis has a variable shell ( Figs 22–23 View FIGURE 22 View FIGURE 23 ) across its wide distribution throughout tropical Australia, PNG and Singapore ( Fig. 25 View FIGURE 25 ). Within this range, we found twenty-three sympatric congeners. Three congeners are sympatric in NC: Siphonaria hienghenensis sp. nov. has a slightly larger, darker shell with a flared siphonal ridge, a smaller AO, and shorter SPM. Siphonaria poindimiensis sp. nov. has a taller, darker shell with fused siphonal ribs, stronger edge scalloping, and longer ED. Siphonaria bourailensis sp. nov. has a shell with a more posteriorly offset apex, uneven ribbing, stronger edge scalloping, a smaller AO, and shorter SPM. Nine congeners are sympatric with S. viridis in PNG and TL: Siphonaria atra has a larger, lower shell with stronger edge scalloping, flared siphonal ridge, and larger BC, and shorter SPM. Siphonaria opposita has a lower, pale to dark brown shell, a larger BC, pointed AO, and longer ED. Siphonaria madangensis sp. nov. has a slightly smaller and lower shell with greater raised ribbing and stronger edge scalloping, a smaller, less prominent AO, larger BC, and shorter, bulbous, threadlike SPM. Siphonaria nusalikensis sp. nov. differs by being much smaller shell, with a darker interior, and BD without distal loop. Siphonaria planucosta sp. nov. has smaller, lower, darker shell with unpatterned interstices, a smaller AO, larger BC, and shorter SPM. Siphonaria forticosta sp. nov. has a larger shell with darker spatula, and a smaller AO. Siphonaria alba has larger, lower shell with stronger edge scalloping, a flared siphonal ridge, and a longer SPM. Siphonaria campestra sp. nov. has smaller shell without exterior patterning, with darker interior, a smaller AO, shorter BD and SPM. For comparison with S. javanica refer to comparative remarks under that species.

Siphonaria maloensis sp. nov. (sympatric in Vanuatu) is of similar shell size but has a darker, grey-brown shell with slightly stronger edge scalloping, an apex offset to posterior and left, and a golden-brown interior. A further eight species are sympatric with S. viridis in tropical Australia (along with S. alba , S. atra , S. campestra sp. nov. and S. opposita ). Siphonaria costellata sp. nov. has a larger, darker shell with a darker interior, a smaller AO, shorter BD, and shorter, wider SPM. Siphonaria gemina sp. nov. has paler shell with stronger edge scalloping and flared siphonal ridge, a smaller AO, and shorter SPM. Siphonaria jiigurruensis sp. nov. has taller shell with more posteriorly offset apex, and paler whitish brown spatula, and a broader ED. Siphonaria oblia has a far smaller shell, weakly ribbed, with strongly posteriorly offset apex, and a smaller to indistinct AO ( Jenkins 2018: 278, figs 3C–D). Siphonaria restis sp. nov. has a shell with stronger edge scalloping, more strongly raised ribbing, a smaller AO, and larger BC. Siphonaria zelandica has lower, paler shell with finer ribbing and a less prominent siphonal ridge, smaller AO and BC, and a smaller, drop-like SPM. Two species are sympatric with S. viridis in Singapore (including S. alba and S. costellata sp. nov.). Siphonaria sirius has lower shell with single rib siphonal ridge, stronger edge scalloping and a paler spatula, a smaller AO, longer ED, shorter BD, larger BC, and a longer SPM. Siphonaria normalis has a smaller, lower shell with a more posteriorly offset apex and less raised ribbing, a smaller AO, larger BC and shorter F1.

Topotypic specimens of L. mirificus ( AM C.585869), L. optivus ( Fig. 22I View FIGURE 22 ) and P. densatus ( Fig. 22E View FIGURE 22 ) are conspecific based on mitochondrial phylogenetics and comparative morphology.

The record of ‘ S. sipho’ in Adam & Leloup (1939: 7, pl. 2, fig. 1a–d) from Java, Bali, Mansinan, PNG and of ‘ S. funiculata ’ (9, pl. 2, figs 2a, b) from Iles Psang, PNG are here attributed to S. viridis and are well within its distributional range ( Fig. 25 View FIGURE 25 ). Hubendick (1946: 30–32, 63) considered the validity of ‘ Parellsiphon promptus’ (= S. viridis ) doubtful, revealing considerable resemblance in shell characters and possible synonymy with S. acmaeoides . Hubendick (1946: 53) further indicated that the mollusc is ‘Entirely yellowish white’ (i.e., likely discolouration in preserved material; external foot dark grey in live S. viridis ). The specimen from Queensland figured in Hubendick (1946: 47, pl. 3, fig. 18) as ‘ S. laciniosa v. sipho’ is attributed here to S. viridis . References to ‘ S. laciniosa ’ (in part) in Hubendick (1946: 47, from New Guinea and Huon Is) and ‘ S. laciniosa ’ in Hubendick (1955: 7, from Cairns ( MV F15031 View Materials , MV F13925, MV F13923) are also most likely specimens of S. viridis . Hubendick’s (1946: pl. 3, fig. 22) specimen of ‘ S. stellata ’ from Broome and Thursday Island (pl. 3, fig. 20) are likely specimens of S. viridis , too. A specimen of ‘ S. zanda ’ from ‘Java Sea’ figured in Hubendick (1946: 91, pl. 4, fig. 8–11) is likely a specimen of S. alba and a specimen from Madagascar (figs 10–11) is likely S. madagascariensis . Specimens of ‘ S. australis ’ from Masthead and Heron Islands ( MV F.13924, 15032, 15034, 15038) mentioned by Hubendick (1955: 7) are likely S. viridis . Reference to ‘ S. laciniosa ’ from New Guinea in Hubendick (1947b: 3) is likely of S. viridis . The records of ‘ S. laciniosa ’ from East coast Malaysia in Way & Purchon (1981: 321) are most likely of S. viridis . Figured specimens of ‘ laciniosa group, unit 25’ in Dayrat et al. (2014) from Timor (fig. 4J), Singapore (fig. 4L), Magnetic Is (fig. 4P), Broome, WA (fig. 4N), PNG (fig. 4Q) and Vanuatu (fig. 4R) correspond well with typical features of S. viridis .

Distribution and habitat. Tropical IWP, including Palau, Singapore (St Johns Island), Vanuatu, and northern Australia (Qld through to Kimberley, WA) as well as Mauritius, Indian Ocean ( Fig. 25 View FIGURE 25 ). Records from Sulawesi, Bali, and PNG arebased on specimens sequenced by Dayrat et al. (2014) and found to be members of unit 25. In this study found in protected positions (e.g., hollows) on moderately exposed rocky boulder shores, mid littoral level (upper oyster zone).