Mimachlamys gloriosa (Reeve, 1853)

Dijkstra, Henk H. & Beu, Alan G., 2018, Living Scallops of Australia and Adjacent Waters (Mollusca: Bivalvia: Pectinoidea: Propeamussiidae, Cyclochlamydidae and Pectinidae), Records of the Australian Museum (Rec. Aust. Mus.) 70 (2), pp. 113-330 : 282-285

Mimachlamys gloriosa (Reeve, 1853)

Figs 88I–J, 90A,C–E, 91, 93A–C,E

Pecten ustulatus Reeve, 1853 : sp. 87, pl. 22, fig. 87.

Pecten gloriosus Reeve, 1853 : sp. 134, pl. 30, figs 134a–b (see Reeve, 1853, errata).

Pecten testudineus Reeve, 1853 : sp. 160, pl. 34, fig. 160.

Pecten similis Baird in Brenchley, 1874: 453, pl. 42, fig. 7.

Mimachlamys subgloriosa Iredale, 1939: 350 , pl. 5, figs 21–21a.

Mimachlamys gloriosa (Reeve) .–Allan, 1950: 280, fig. 7; Lamprell & Whitehead, 1992: [22], pl. 9, fig. 52; Slack- Smith & Bryce, 2004: 237; Raines & Poppe, 2006: 272–273, lower figs; pl. 218, figs 1–3; pl. 219, figs 1–6; Huber, 2010: 211; Dijkstra, 2013: 92, pl. 23, figs 3a–d, pl. 32, figs 1a–b.

Chlamys gloriosa (Reeve) .–Coleman, 1982: 280, fig. 771; Dijkstra, (1983–1994) 1983: 19, figs; Dharma, 1992: 84, pl. 20, figs 2–2d.

Chlamys (Mimachlamys) gloriosa (Reeve) .– Rombouts, 1991: 29, pl. 11, figs 4–4c; Dharma, 2005: 248, pl. 99, figs 1a–m.

Comments on synonymy. Although Reeve introduced Pecten ustulatus (May 1853) a few months earlier than Pecten gloriosus (Aug 1853) , we prefer to use the latter name because of its wide general acceptance. This is further complicated by Reeve (1853: caption to pl. 30, sp. 134, Jun 1853) initially applying the name Pecten nobilis to this species, but later (Reeve, 1853: errata; evidently issued after

Figure 90. A, C–E, Mimachlamys gloriosa (Reeve) , 2 pairs; (A, C) smooth form, specimen in Fig. 88I, J; lv exterior (A), rv interior (C); (D, E) scaly form, AM C.069989, Rodds Harbour, Port Curtis, QLD; rv interior (D), lv exterior (E). B, F, G, I, Mimachlamys punctata (Gmelin) , 2 pairs; (B, I) AM C.097537, Roebuck Bay, Broome, WA; rv interior (B), lv exterior (I); (F, G) AM C.303777, Langford Reef, Whitsunday Group, GBR, QLD; rv interior (F), lv exterior (G). H, J, Mimachlamys heterophyseta Beu & Darragh , lv only, AM C.079057, Great Australian Bight, WA, 33°12.00'S 128°43.00'E, 75–147 m; lv exterior (H), lv interior (J). Scale bars represent 30 mm (A, C–E, H, J), 20 mm (B, F, G, I).

the last plate, dated Aug 1853) apparently realising that he had previously (Reeve, Nov 1852) applied the same name to pl. 1, fig. 3, now universally known as Mimachlamys nobilis ( Reeve, 1852) , and providing the new name Pecten gloriosus for pl. 30, fig. 134a–b in the errata. As first revisers, we select the name Pecten gloriosus to be used as the valid name for the species named Pecten gloriosus , Pecten testudineus and Pecten ustulatus by Reeve (1853).

Type data. Pecten ustulatus Reeve : figured holotype (pr) (H 65.1 mm, L 61.0 mm, D 23.9 mm) (Reeve 1853: pl. 22, fig. 87) NHMUK [not registered]. Type locality: Australia. Herein restricted to Moreton Bay, QLD.

Pecten gloriosus Reeve : figured syntype (pr) (H 87 mm, L 84 mm) (Reeve 1853: pl. 30, fig. 134a) NHMUK 1950.11.14.35; 3 syntypes NHMUK 1950.11.14.36–38. Type locality: Australia, QLD, Moreton Bay .

Pecten testudineus Reeve : three syntypes (pr) NHMUK 20010210 . Type locality: “ Amboyna ” [ Indonesia, Maluku, Ambon].

Pecten similis Baird : possible holotype (pr) (H 42 mm, L 38 mm) NHMUK [not registered].Type locality: “Tongatabu, Friendly group” [Tongatapu, Tongatapu Group , Tonga].

Mimachlamys subgloriosa Iredale : holotype (pr) (H 43 mm, L 40 mm) AM C.089668 (Fig. 93B, E). Type locality: Australia, QLD, GBR, Low Isles , 9–12 fathoms [16–22 m].

Comments on type data. The auricles of the holotype of Pecten ustulatus are damaged, although the auricles have been “restored” on Reeve’s figure (1853: pl. 22, fig. 87).

Additional material examined. — AUSTRALIA: QUEENSLAND: Torres Strait, Murray Island, 9°56'S 144°04'E, dead, beach (1 v, C.357620); N Gulf of Carpentaria, 11°34'S 138°36'E,dead, 59 m (1 v,C.346931); Gulf of Carpentaria , Mapoon , 11°58'S 141°53'E, dead (1 pr, C.348434); Gulf of Carpentaria , 10 ml SW of Mapoon, 12°05'S 141°40'E, dead, 18 m (6 v, C.014079); Gulf of Carpentaria , Albatross Bay , Weipa , 12°38'S 141°43'E, alive, 7 m (1 pr, C.094501); NE Gulf of Carpentaria, W of Weipa, 12°42'S 141°31'E,dead, 18 m (1 v,C.346944); Mid Gulf of Carpentaria , 14°09' S 139°40'E,dead, 61 m (2 v,C.346925); Gulf of Carpentaria , W of Edward River, 14°44'S 141°18'E,dead, 22 m (1 pr,C.114866); Gulf of Carpentaria , W of Edward River, 14°46'S 141°20' E,dead, 18 m (2 v,C.346941); Gulf of Carpentaria , W of Mitchell River, 15°09'S 141°22'E, dead, 14.5 m (1 v, C.346933); E Gulf of Carpentaria, W of Nassau River, 15°51'S 140°54'E,alive, 22 m (4 pr + 7 v,C.111500); E Gulf of Carpentaria, W of Nassau River, 15°53'S 140°42' E, alive, 25.6 m (5 pr, C.114871); Gulf of Carpentaria , W of

Figure 91. Distribution of Mimachlamys gloriosa (Reeve) .

Nassau River , 15°53'S 141°02'E, dead, 20 m (1 pr, C.109332) ; E Gulf of Carpentaria , W of Nassau River, 15°53'S 141°13' E,dead, 11 m (1 v,C.346932) ; E Gulf of Carpentaria , SW of Nassau River, 16°06'S 140°44'E, alive, 22 m (4 pr, C.110630) ; SE Gulf of Carpentaria , W of Gilbert River, 16°41'S 140°09'E,dead, 18.3 m (1 v, C.110624) ; Gulf of Carpentaria, Forsyth Island, 16°50'S 139°06'E, dead,beach (2 v,C.014849);SE Gulf of Carpentaria , W of Point Burrowes, 16°57'S 140°16'E, alive, 18 m (2 v, C.346921; 1 pr, C.348457) ; SE Gulf of Carpentaria , W of Point Burrowes, 16°57'S 140°35'E, alive, 14.5 m (2 pr,C.346923) ; SE Gulf of Carpentaria , W of Point Burrowes, 16°58' S 140°0'E, dead, 18 m (1 v,C.111259) ; Gulf of Carpentaria , S of Sweers Island, 17°06'S 139°37'E, dead, 9–22 m (1 v, C.346939) ; Gulf of Carpentaria, 28 ml S of Sweers Island, 17°06' S 139°37'E,dead (9 v,C.346943); Torres Strait, Murray Island , 9°56'S 144°04'E, dead (1 pr, C.348278); Torres Strait, 10°11'S 141°48'E, dead, 13 m (2 pr, C.164906) ; Torres Strait , 10°22' S 141°42' E, alive, 16 m (2 pr, C.164911) ; Torres Strait, Thursday Island, 10°35'S 142°13'E, alive (12 v, C.097439; 3 pr, C.346960); Torres Strait , Friday Island , 10°36'S 142°10'E, dead (9 v,C.094502); Cape York Peninsula , 10°41'S 142°31'E,alive (2 pr, C.097435); Cape York , Telegraph Station , 10°42' S 142°28'E, dead, beach (3 v, C.036313); Cape York ,near Telegraph Station , 10°42'S 142°28' E,dead (1 pr,C.103811); Cape York Peninsula , Somerset Bay , 10°44'S 142°35'E, alive (1 pr, C.348484); Cape York Peninsula , Albany Passage , 10°45'S 142°37'E, dead, 7–26 m (many v,C.036128) ; Cape York Peninsula, Albany Passage, 10°45'S 142°37'E, alive (3 pr,C.131991); Cape York Peninsula, Albany Passage , 10°45' S 142°37' E, alive, 16–22 m (17 v, C.055697) ; Cape York, Red Island Point, near Bamaga , 10°51' S 142°21'E, alive (1 pr, C.131997); Cairncross Island , 11°14' S 142°55'E,alive (6 pr,C.097441);2 ml NE of Hannibal Island, 11°33'S 142°57'E, dead, 22–23 m (1 pr, C.347792) ; GBR, Lizard Island, 14°40'S 145°28'E,dead (1 v,C.347793);off Bow Reef, near Cape Sidmouth , 13°20'S 143°40'E, dead, 19 m (1 v, C.002576) ; 5 ml WNW of Lizard Island , 14°30'S 145°22'E, dead, 20 m (1 pr, C.130385) ; 0.5 ml SE of Lizard Island , 14°41'S 145°29'E, dead, 35 m (1 v, C.153561) ; Turtle Island , 14°44'S 145°12'E, dead, 14.5 m (1 v, C.347795) ; 0.25 ml N of North Direction Isle , 14°44'S 145°31' E, dead, 34.5 m (1 v, C.089667;1 v, C.094500) ; off Cape Flattery, Decapolis Reef , 14°50'S 145°17'E, dead, 12–14 m (1 v, C.347796) ; off Two Isles , 15°01'S 145°26'E, dead (2 v, C.161021); 0.5 ml W of Two Isles, 15°01'S 145°26'E, dead, 30 m (5 v, C.347794) ; Cooktown, 15°28'S 145°15'E, dead (1 v, C.106987);off Cooktown, 15°28' S 145°23' E,alive (8 pr,C.097440); Cairns Reef lagoon & between Cairns Reef & Hope Island , 15°42'S 145°30'E,dead, 9–18 m (12 v,C.027531) ; Penguin Channel , 16°15'S 145°31'E,alive, 18–28.5 m (1 pr,C.093400) ; Penguin Channel , 16°15'S 145°31'E, dead, 22–25 m (8 v, C.094499) ; Low Isles , 16°23' S 145°34'E, dead, 16–22 m (1 pr, C.075258; 6 v, C.093403) ; Low Isles, 16°23'S 145°34'E, alive (1 pr, C.089668;24 v,C.119460);off Cairns , 16°51'S 146°01'– 146°04'E,dead, 33–35 m (many v, C.347804; 12 v, C.348267) ; off Cairns ,GBR, 16°52'– 16°53'S 146°06' E,dead, 37–38 m (5 v,C.348263) ; Cairns Harbour, 16°53'S 145°48'E, dead (1 v,C.094498);off Cairns , GBR, 16°55'S 146°07'E, dead, 37–40 m (5 v, C.348265) ; Magnetic Island, Horseshoe Bay , 17°07'S 146°51'E, dead, 6–9 m (1 v, C.348261) ; Family Islands, Dunk Island, 17°57'S 146°10'E, dead (1 v, C.009983; 1 pr, C.047367); off Townsville , 18°40'S 146°55'E, dead, 40–41 m (2 v, C.348266) ; off Townsville , 6–7 ml E of Keeper Reef, 18°45'S 147°23'E,dead, 43 m (6 v, C.347812) ; off Ingham , 18°53'S 147°35'E, alive, 58 m (1 pr, C.337113) ; off Townsville , 19°0' S 147°0'E, alive, 45 m (1 pr, C.348268) ; Magnetic Island, 19°08'S 146°50' E, dead (6 v, C.094496); Bohle River mouth, N of Townsville, 19°11'S 146°45'E, dead (1 v, C.068508); Townsville , Rowes Bay , 19°14'S 146°48'E, dead (1 v, C.107188); Townsville , Rowes Bay , 19°14'S 146°48'E, dead, intertidal (1 pr, C.131996); Townsville , 19°16'S 146°49'E, dead (3 v, C.094497; 2 pr, C.347809; 17 v, C.348428); S of Townsville , 19°17'S 147°32'E, dead, 24 m (7 v, C.348264) ; off Cape Upstart , 19°42' S 147°45'E,alive, 36 m (4 pr,C.097517) ; off Bowen , 19°44'S 148°14'E, dead, 40 m (1 v, C.119545) ; E of Bowen , 19°45'S 148°19'E, dead, 46 m (3 v, C.348269) ; W of Hayman Island , 20°03'S 148°50'E, dead, 33 m (22 v, C.348274) ; Bowen, 20°04'S 148°22' E, dead (1 pr, C.348432); Sinclair Bay, Cape Gloucester , 20°07'S 148°27'E, alive (2 pr, C.097438); Edgecumbe Bay , Sinclair Bay , 20°07'S 148°27' E, dead (3 pr,C.348426); Edgecumbe Bay , Bowen , 20°08'S 148°23' E, dead (1 v, C.131993); Whitsunday Islands , Lindeman Island , 20°27' S 149°02'E, dead (many v, C.348270); off Shaw Island , N of Mackay, 20°29'S 149°05'E, dead, 37 m (1 v, C.348273) ; E of Mackay , 20°52'S 149°29'E, dead, 35 m (8 v, C.116558) ; Seaforth, N of Mackay, 20°54'S 148°58'E, dead (1 v, C.059194); E of Sarina , 21°27' S 150°08'E, dead, 42 m (many v, C.119596) ; E of Sarina , 21°28'S 150°08'E, dead, 40 m (26 v, C.348275) ; GBR, Swain Reefs, 3 km NE of W side of Bylund ( Gillett ) Cay , 21°42'S 152°26'E, dead, 64–73 m (many v, C.153560) ; SE of Sarina , 21°47'S 150°34' E, dead, 59 m (many v, C.116486) ; E of Broad Sound , 21°58'S 150°45' E, dead, 57 m (many v, C.347637) ; off Broad Sound , 22°06'S 150°49'E, dead, 53 m (many v, C.116496) ; SE of Swain Reefs , 22°31'S 152°32'E,dead, 100 m (many v,C.151489) ; off Yeppoon , 22°40'S 151°16' E, dead, 58 m (6 v, C.348280) ; off Yeppoon , 22°42' S 151°37'E, dead, 68 m (3 v,C.348281) ; 30 ml NE of Yeppoon , 22°50'S 151°11'E,alive, 46–55 m (12 pr,C.073249) ; NE of Rockhampton , 22°50'S 151°39'E, dead, 64 m (2 v, C.348279) ; off Yeppoon, off North Keppel Island , 23°02'S 151°10'E,alive, 51 m (5 pr,C.348491) ; Keppel Bay, North Keppel Island, 23°04' S 150°54'E, dead (4 v, C.348430); North Keppel Island , close inshore to NW end,alive, 7 m (1 pr,C.348488) ; Keppel Bay, Yeppoon , 23°08'S 150°45'E, alive (3 pr, C.131995; 1 pr, C.348282); 1.5 ml NW of South Keppel Island, 23°08'S 150°56'E, alive, 13–20 m (7 pr + 1 v, C.077056) ; Keppel Bay , NE of South Keppel Island, between Outer Rock & Man & Wife, 23°08'S 150°56'E, dead, 24–26 m (2 v, C.348271) ; Capricorn Channel , 23°08'S 152°16' E,dead, 155 m (2 v,C.348272) ; Keppel Bay , 1.5 ml NW of South Keppel Island, 23°09'S 150°57'E, dead, 13–20 m (2 v, C.070801) ; Capricorn Channel , 4 ml E of North Reef, 23°09'S 151°58'E, alive, 64 m (2 pr + 3 v, C.348277) ; Capricorn Channel, off North Reef , 23°09' S 151°59'E, dead, 54 m (1 pr, C.348284) ; Keppel Bay, off Humpy Island , 23°13' S 150°58'E, dead, 4 m (1 v, C.124011) ; Capricorn Group, North West Island, 23°18'S 151°42' E,alive (7 v, C.057647; many v, C.131992; 2 v, C.161006); Capricorn Group, off North West Island , 23°18'S 151°42'E, alive, 36 m (4 v, C.348283) ; Keppel Bay, 23°25' S 150°55'E, dead (1 v, C.131994); Capricorn Group, One Tree Island , 23°30'S 152°05' E, dead, 55 m (23 v, C.348276) ; Gladstone Harbour, 23°51'S 151°16'E,dead (9 v,C.089474);S of Gladstone, Tannum Sands, 23°57' S 151°22'E, dead, beach (1 v, C.347625); Port Curtis, Rodds Harbour , 24°0'S 151°34'E,alive (1 pr, C.069989;1 pr,C.080062); Port Curtis , Hummock Hill Island , 24°01'S 151°28'E,alive (2 pr,C.062604);off Burnett Heads, 24°46'S 152°24'E, alive, 27 m (12 pr, C.097437) ; Bargara, 24°49'S 152°28'E, dead (2 v, C.348429); S of Fraser Island, 25°28'S 153°0'E, alive (1 pr,C.070291); off S end Frazer Island , 25°48'S 153°46'E, dead, 73 m (1 v, C.347624) ; off Tin Can Bay , 25°50' S 153°27'E, alive (1 pr, C.062503); E of Caloundra, 26°48'S 153°35'E, dead, 91–119 m (4 pr, C.097445) ; near Moreton Bay, 27°13'S 153°20'E, alive (1 pr,C.081213); Moreton Bay, Redcliffe Beach , 27°14'S 153°07'E, alive (1 v, C.089483; 3 pr, C.147401); Moreton Bay , off Redcliffe Beach , 27°14'S 153°07'E, alive (1 pr,C.094494); Moreton Bay , 27°15'S 153°15'E,alive (3 pr, C.047362;2 pr, C.064544;1 pr + 1 v, C.077041); Moreton Bay , 27°15'S 153°15'E, alive, 3.5–11 m (7 v, C.094493) ; Moreton Bay, Bramble Bay, Humpybong , 27°17'S 153°04' E,alive (1 pr,C.019174); Moreton Bay , Sandgate , Cabbage Tree Creek , 27°20' S 153°06'E, alive (2 pr, C.102906); Moreton Bay , Green Island , 27°26'S 153°14'E, dead (1 v, C.347635); Moreton Bay , off Peel Island , 27°30'S 153°21' E, alive, 9 m (many, C.097443; 5 pr, C.097444) ; Moreton Bay, off Dunwich, Stradbroke Island , 27°30'S 153°24'E,alive, 5–7 m (7 v,C.075250;3 v,C.347633) ; Moreton Bay, Dunwich, Stradbroke Island , 27°30'S 153°24' E, alive (1 pr, C.348478); Moreton Bay , Peel Island , 27°30'S 153°21'E, alive (3 pr, C.094495). NEW SOUTH WALES: Brunwsick Heads , 28°32'S 153°33'E, dead, beach (1 v, C.098628); off Coffs Harbour, 30°36'– 30°39'S 153°19'– 153°18'E, dead, 165 m (1 v, C.123478) ; Port Stephens, 32°42'S 152°05'E, alive (2 pr, C.012155). WESTERN AUSTRALIA: Shark Bay, South Passage , 26°10'S 113°13'E, dead (1 v, C.069374); Exmouth Gulf, SE of Exmouth Homestead, 22°24'S 114°08'E, alive (1 pr, C.348477); North West Shelf , 26 n. ml NNE of Dampier , 20°14'S 116°50'– 116°50.6'E, alive, 40–41 m (2 pr + 4 v, C.346912) ; North West Shelf , 50 n. ml NNE of Port Hedland, 19°30' 19°31'S 118°52' – 118°49'E, dead, 38–40 m (4 v, C.149900) ; North West Shelf , 52 n. ml NNE of Port Hedland,19°30' – 19°28.2'S 118°49'– 118°55.4' E, dead, 36–37 m (5 pr + 5 v, C.149172;14 v,C.149202) ; North West Shelf , 74 n. ml NNE of Port Hedland,19°05' – 19°05.3'S 118°53'– 118°54'E, dead, 80 m (1 v, C.149987) ; North West Shelf , 77 n. ml NNE of Port Hedland,19°05' – 19°04.9'S 118°58'– 118°58.2' E, dead, 82 m (3 v, C.149916) ; North West Shelf , 76 n. ml NNE of Port Hedland, 19°04'– 19°04.7' S 118°50'– 118°50.8'E, dead, 81 m (4 v, C.148635; 2 v, C.148636) ; North West Shelf , 78 n. ml NNE of Port Hedland, 19°04'– 19°04.3'S 118°47'– 118°47.6'E, dead, 82 m (11 v, C.149222) ; North West Shelf , 78 n. ml NNE of Port Hedland,19°04'– 19°04.2' S 119°04'– 119°0.7'E,dead, 82 m (34 v,C.149316) ; North West Shelf , 80 n. ml NNE of Port Hedland, 19°03'– 19°03.4' S 119°03'– 119°03.5' E, dead, 82 m (4 v, C.346913) ; North West Shelf , 94 n. ml NNE of Port Hedland, 18°48'S 119°0'E, dead, 92–94 m (2 v, C.346911) ; c. 80 ml NW of Broome , 17°20'S 121°11'E, dead, 95 m (1 v, C.160981) . NORTHERN TERRITORY: Arafura Sea , c. 110 ml N of Melville Island, 9°34'S 131°22'E,dead, 135 m (1 v,C.123870) ; Arafura Sea , 10°13' S 133°58'E,alive, 72 m (3 pr,C.348486) ; Arafura Sea , c. 45 ml N of Croker Island, 10°17'S 132°38'E, dead, 65 m (3 v,C.346918) ; Arafura Sea , 91 km N of Goulburn Island, 10°42' S 133°36' E,dead, 58 m (4 v,C.346937) ; Darwin, Waigait, 11°28'S 130°50' E, alive (7 pr, C.348472); Darwin, Stokes Hill Powerhouse , 11°28'S 130°50' E, alive (15 pr, C.348475); off Darwin, 12°04'S 123°50' E, dead, 132 m (3 v, C.070519) ; Arnhem Land, Gove Peninsula, Yirrkala , 12°15'S 136°53'E, dead (1 v, C.346919); Port Darwin , 12°28'S 130°50'E, dead (2 v, C.013918); Daly River mouth, 13°19'S 130°15'E, dead (1 pr, C.019478); Anson Bay , 13°20'S 130°10'E, dead (4 v, C.040801); Gulf of Carpentaria , Groote Eylandt , 14°0'S 136°25' E,dead (1 v,C.346920). — PAPUA NEW GUINEA: New Britain, Rabaul , 4°12'S 152°11'E,dead (1 v,C.348447); Gulf of Papua , off Cape Possession , 8°37'S 146°20'E, dead, 27 m (2 v, C.088004) ; SW Port Moresby, Lolorua Island , 9°30'S 147°06' E, dead, 13–18 m (5 v, C.348443) ; Port Moresby, Manubada Island , 9°31'S 147°10'E, off W end,just inside of outer reef, alive, 18–22 m (many, C.348442) ; Louisiade Archipelago, Nimoa Island, Calvados Chain & Rossel Island , 11°18'S 153°15'– 154°0'E, dead (1 v, C.348444; 3 v, C.348446).— NEW CALEDONIA: Baaba Island , 20°03'S 163°58'E,W coast,alive, 0–0.5 m (1 pr,C.348466) ; Poum Bay, Daomboui Island , 20°09'S 163°59'E, alive, 0–3 m (1 pr, C.348468) ; Poum, 20°13'S 164°03'E, dead (1 pr, C.348438); Poum, Recif Bay , 20°13'S 164°03'E, alive, 1–4 m (1 pr,C.348469) ; Nouméa, North Dumbea, Baie Papaya , 22°11'S 166°19'E,alive, 0–3 m (1 pr, C.348465) ; Nouméa, Baie des Isoles, Magenta , Ouemo , 22°16'S 166°29' E, alive (2 pr,C.348691); Nouméa, Baie des Citrons , 22°18'S 166°26'E,dead (1 v,C.106418); Nouméa, Ile Ste. Marie , 22°18' S 166°29'E, alive, 0–2 m (3 v, C.348439; 10 pr + 3 v, C.348440; 1 pr, C.348461) ; Anse Vata, Aquarium de Nouméa , 22°19'S 166°27'E, alive (many,C.348435;many,C.348436); Nouméa, Anse Vata , 22°31.7' S 166°45' E,alive, 1–3 m (1 pr, C.348458) . TASMAN SEA: off Newcastle, Taupo Guyot , 33°06'S 156°09'E, dead, 154–164 m (5 v, C.139602).

Description. Shell rather compressed, up to c. 120 mm high, juvenile elongate, adult subcircular, equivalve, equilateral, left valve slightly more convex than right, auricles highly unequal, umbonal angle c. 80–85°; most specimens dark brick red with paler maculations.

Both valves sculptured with 22–23 evenly spaced primary radial plicae bearing variably prominent, widely set scales, with secondary squamose interstitial riblets near ventral margin (absent in juveniles). Interstitial microsculpture of irregular antimarginal scratches, weakly developed on central part of disc, more prominent near posterior margin.Anterior auricle of left valve with c. 8 scaly radial riblets; of right valve with 5–6 more prominent riblets. Posterior auricle of left valve with similar sculpture to anterior, although weaker and with fewer riblets. Dorsal margin straight. Resilifer narrowly triangular. Byssal notch deep, byssal fasciole rather broad. Functional ctenolium well-developed, with c. 5 teeth. Interior furrowed; internal rib carinae short, prominent around ventral margin. Resilial and dorsal teeth prominent.

Dimensions. Illustrated specimens: N QLD, Port Curtis, Rodds Harbour (AM C.069989; scaly, coarsely sculptured specimen): rv: H 77.4, L 74.4 mm; lv: H 76.3, L 73.4 mm; D 26.0 mm; S QLD, trawled off Moreton Island (AM C.081213; weakly sculptured specimen): rv: H 86.6, L 79.3 mm; lv: H 85.7, L 78.7 mm; D 27.9 mm; holotype of Mimachlamys subgloriosa Iredale, AM C. 089668 (Fig. 93B, E), QLD, GBR, Low Isles, 16–22 m: H 43 mm, L 40 mm.

Habitat. Living in the littoral zone, byssally attached to rocks or coral, or amongst coral rubble on soft sediment (sand and/or mud). In Western Australia often attached to pipes or ropes in deeper water, occasionally found attached to ropes hanging under floats washed as far south as Perth (H. Morrison, pers. comm.).

Distribution. Tropical western Pacific, from the Philippines southwards to Indonesia and northwestern, northern and northeastern Australia, eastwards to Tonga (Raines & Poppe, 2006: 272); Philippines toAustralia, 17–110 m (Huber, 2010: 211); Philippines, 10–30 m ( Raines, 2010: 640; Dijkstra, 2013: 92); Vanuatu, 91–110 m (Dijkstra & Maestrati, 2012: 401). Maximum depth range of live-taken specimens is in the intertidal zone to 110 m. Present specimens from Australia alive at 3.5– 72 m.

Remarks. Mimachlamys gloriosa closely resembles Mimachlamys crassicostata (G. B. Sowerby II, 1842) from northern Chinese and Japanese waters. Mimachlamys gloriosa can be distinguished from M. crassicostata by its smaller size ( M. gloriosa up to c. 120 mm in height, M. crassicostata up to c. 140 mm), its different sculpture ( M. gloriosa c. 22 plicae with secondary riblets in late growth stage; M. crassicostata c. 24 plicae lacking interplical secondary sculpture), and its colour ( M. crassicostata is more brightly coloured, resembling the colour of M. spinicostata ). The eggs and larval development of New Caledonian specimens of M. gloriosa were described by Lefort (1992).