Talopena maestratii, Herbert, 2024

Herbert, David G., 2024, The Umboniinae (Mollusca: Gastropoda: Trochidae) of New Caledonia, with descriptions of two new genera and eight new species, plus an additional new species from the Bismarck Sea, European Journal of Taxonomy 973, pp. 1-143 : 80-92

Talopena maestratii sp. nov.

urn:lsid:zoobank.org:act:B3E16EEF-DA5E-415A-8C12-F51FBF6B38E9

Figs 39–43

Monilea cf. menkei – Héros et al. 2007: 209.

Diagnosis

Talopena maestratii sp. nov. is characterised by its relatively large and robust shell bearing crisp, evenly sized spiral cords with fine, close-set spiral microlirae in their intervals; cords undulant rather than beaded; parietal region with callus lobe at insertion of columella; thickened peri-umbilical band bears coarse pliculae and termination of umbilical funicle frequently yellow.

Etymology

Named for Philippe Maestrati (MNHN), in recognition of his enormous contribution to our knowledge of marine molluscan diversity, particularly in New Caledonia, through his many years of field work in the region, from Expédition Montrouzier (1993) to KOUMAC 2.3 (2019).

Material examined

Holotype ( Fig. 39A–D )

NEW CALEDONIA • empty shell; Koumac , Stn 942; 20°37′ S, 164°13′ E; depth 15 m; 28 Apr. 1988; B. Richer-ORSTOM leg.; MNHN-IM-2000-38858 .

Paratypes

NEW CALEDONIA – Grande Terre, Poum • 1 specimen, living; Stn 1004; 20°10′ S, 163°58′ E; depth 15 m; 2 May 1988; B. Richer-ORSTOM leg.; MNHN-IM-2000-38859. – Grande Terre, Koumac • 1 specimen, living; Stn KD518; 20°34.7′ S, 164°12.5′ E; depth 5–6 m; 1 Nov. 2019; KOUMAC 2.3 leg.: sable gris à Halophila ; MNHN-IM-2000-38860 • 1 specimen, living; Chenal de l’Infernet , Stn 1304; 20°38.6′ S, 164°13.2′ E; depth 12–15 m; Oct. 1993; Expédition Montrouzier leg.; sable gris, dalle; MNHN-IM-2000-38861 • 2 specimens, living; Stn KD 578; 20°43.8′ S, 164°16.4′ E; depth 11–12 m; 19 Nov. 2019; KOUMAC 2.3 leg.; sable fin gris à Halophila ; DNA vouchers; MNHN-IM-2019-9731 and -9732 (image PM751 ). – Grande Terre, Nouméa • 2 specimens, living; Grand Récif Sud , Stn 546; 22°53′ S, 166°52′ E; depth 33 m; 15 Jul. 1985; B. Richer-ORSTOM leg.; MNHN-IM-2000-38862 .

Other material

NEW CALEDONIA – Lagon Nord – Belep • 4 specimens, living; Lagon Nord, Stn 542; 19°06′ S, 163°10′ E; depth 50 m; 6 Mar. 1985; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Lagon Nord, Stn 1157; 19°10′ S, 163°10′ E; depth 48 m; 30 Oct. 1989; B. Richer-ORSTOM leg.; MNHN • 1 specimen, living; Lagon Nord, Stn 1197; 19°36′ S, 163°22′ E; depth 41 m; 1 Nov. 1989; B. Richer-ORSTOM leg.; MNHN • 3 specimens, living; Stn 1094; 19°54′ S, 163°41′ E; depth 26 m; 24 Oct. 1989; B. RicherORSTOM leg.; MNHN • 3 specimens, dead; Stn 1063; 20°03′ S, 163°47′ E; depth 31 m; 23 Oct. 1989; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Stn 1128; 19°31′ S, 163°52′ E; depth 26 m; 26 Oct. 1989; B. Richer-ORSTOM leg.; MNHN • 1 specimen, living; Stn 1072; 19°56′ S, 164°02′ E; depth 20 m; 23 Oct. 1989; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Stn 1073; 20°00′ S, 164°03′ E; depth 28 m; 23 Oct. 1989; B. Richer-ORSTOM leg.; MNHN. – Grande Terre, Poum • 2 specimens, dead; Stn 1024; 20°06′ S, 163°50′ E; depth 26 m; 3 May 1988; B. Richer-ORSTOM leg.; MNHN • 3 specimens, living; Stn 1027; 20°03′ S, 163°51′ E; depth 29 m; 3 May 1988; B. Richer-ORSTOM leg.; MNHN • 2 specimens, living; Stn 1015; 20°10′ S, 163°52′ E; depth 25 m; 3 May 1988; B. RicherORSTOM leg.; MNHN • 2 specimens, living; Stn 1008; 20°11′ S, 163°53′ E; depth 27 m; 2 May 1988; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Stn 1010; 20°09′ S, 163°57′ E; depth 16 m; 3 May 1988; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Stn 989; 20°18′ S, 163°57′ E; depth 21 m; 30 Apr. 1988; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Stn 1019; 20°06′ S, 163°58′ E; depth 23–24 m; 3 May 1988; B. Richer-ORSTOM leg.; MNHN • 2 specimens, living; Stn 985; 20°20′ S, 163°58′ E; depth 15–17 m; 30 Apr. 1988; B. Richer-ORSTOM leg.; MNHN. – Grande Terre, Koumac • 2 specimens, living; Passe du Baron, Stn 1307; 20°33.7′ S, 164°10.3′ E; depth 12 m; Oct. 1993; Expédition Montrouzier leg.; sable à Heteropsammia ; MNHN • 2 specimens, dead; Chenal de l’Infernet, Stn 1305; 20°36.2′ S, 164°11.0′ E; depth 12–15 m; Oct. 1993; Expédition Montrouzier leg.; sable gris; MNHN • 18 specimens, living; Chenal de l’Infernet, Stn 1304; 20°38.6′ S, 164°13.2′ E; depth 12–15 m; Oct. 1993; Expédition Montrouzier leg.; sable gris, dalle; MNHN • 3 specimens, living; around l’Îlot Kendec, Stn 1309; 20°40.5′ S, 164°13.4′ E; depth 18 m; Oct. 1993; Expédition Montrouzier leg.; sable gris; MNHN • 1 specimen, dead; near Passe de Koumac, Stn KR627; 20°38.6′ S, 164°13.5′ E; depth 12 m; 24 Sep. 2018; KOUMAC 2.1 leg.; MNHN • 1 specimen, dead; drop-off of l’Îlot Kendec, Stn 1308; 20°40′ S, 164°15.2′ E; depth 15–20 m; Oct. 1993; Expédition Montrouzier leg.; dalle; MNHN • 1 specimen, dead; Passe Deverd, Stn 1322; 20°45.2′ S, 164°15.2′ E; depth 53–71 m; Oct. 1993; Expédition Montrouzier leg.; sable vaseux; MNHN • 2 specimens, dead; Stn KD578; 20°43.8′ S, 164°16.4′ E; depth 11–12 m; 19 Nov. 2019; KOUMAC 2.3 leg.; sable fin gris à Halophila ; MNHN. – Grande Terre, Touho • 1 specimen, living; Grand Récif Mengalia, Stn 871; 20°36′ S, 165°00′ E; depth 27 m; 13 Jan. 1987; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Grand Récif Mengalia, Stn 866; 20°38′ S, 165°03′ E; depth 26 m; 13 Jan. 1987; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; parages de la Thiem, Stn 1268; 20°45.2′ S, 165°08.0′ E; depth 9–11 m; Sep. 1993; Expédition Montrouzier leg.; sable fin; MNHN • 1 specimen, dead; Grand Récif Mengalia, Stn 857; 20°36′ S, 165°09′ E; depth 31 m; 12 Jan. 1987; B. Richer-ORSTOM leg.; MNHN • 1 specimen, living; around Baie de Touho, Stn 1251; 20°46.0′ S, 165°13.0′ E; depth 6–15 m; Sep. 1993; Expédition Montrouzier leg.; vase, sable, herbiers; SEM; MNHN • 1 specimen, dead; Chenal de Touho, Stn 1261; 20°46.5′ S, 165°15.75′ E; depth 45–56 m; Sep.1993; Expédition Montrouzier; sable détritique; MNHN. – Grande Terre, Poindimié • 1 specimen, dead; Stn 765; 21°14′ S, 165°42′ E; depth 35 m; 8 Jan. 1987; B. RicherORSTOM leg.; MNHN. – Grande Terre, Canala • 1 specimen, dead; Stn 755; 21°12′ S, 165°48′ E; depth 43 m; 7 Jan. 1987; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Stn 708; 21°24′ S, 166°05′ E; depth 34–35 m; 10 Aug. 1986; B. Richer-ORSTOM leg.; MNHN. – Grande Terre, Baie de St Vincent • 1 specimen, dead; Stn 218; 21°52′ S, 165°46′ E; depth 15 m; 21 Sep. 1984; B. RicherORSTOM leg.; MNHN • 1 specimen, dead; Stn 217; 21°53′ S, 165°47′ E; depth 16 m; 21 Sep. 1984; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Stn 199; 22°02′ S, 166°00′ E; depth 50 m; 19 Sep. 1984; B. Richer-ORSTOM leg.; MNHN • 2 specimens, living; Stn 185; 22°05′ S, 166°02′ E; depth 15 m; 19 Sep. 1984; B. Richer-ORSTOM leg.; MNHN. – Grande Terre, Nouméa • 1 specimen, living; Stn DE57; 22°10.6′ S, 166°07.1′ E; depth 18–19 m; 30 Apr. 1987; B. Richer de Forges-IRD leg.; MNHN • 1 specimen, dead; Stn s/n; 22°17′ S, 166°08′ E; depth 10–30 m; Apr. 1987; B. Richer de Forges-IRD leg.; MNHN • 1 specimen, living; Stn 4; 22°23′ S, 166°21′ E; depth 9 m; 21 May 1984; B. Richer-ORSTOM leg.; MNHN • 14 specimens, living; Crouy ; 22°21.5′ S, 166°21.7′ E; depth 1–6 m; 1990–2003; Claude Berthault leg.; MNHN • 1 specimen, dead; Stn 259; 22°20′ S, 166°22′ E; depth 18 m; 7 Nov. 1984; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Stn 3; 22°21′ S, 166°22′ E; depth 15 m; 21 May 1984; B. Richer-ORSTOM leg.; MNHN • 1 specimen, living; Stn 253; 22°22′ S, 166°23′ E; depth 16 m; 7 Nov. 1984; B. Richer-ORSTOM leg.; MNHN • 2 specimens, living; Stn DE66; 22°21.5′ S, 166°23.4′ E; depth 23 m; 30 Apr. 1987; B. Richer de Forges-IRD leg.; MNHN • 1 specimen, living; Stn 2; 22°19′ S, 166°24′ E; depth 14 m; 21 May 1984; B. Richer-ORSTOM leg.; MNHN • 1 specimen, living; Stn 281; 22°24′ S, 166°24′ E; depth 10 m; 9 Nov. 1984; B. Richer-ORSTOM leg.; MNHN • 2 specimens, living; Stn DE42; 22°27.5′ S, 166°25.3′ E; depth 15 m; 29 Apr. 1987; B. Richer de Forges-IRD leg.; MNHN • 1 specimen, dead; channel Îlot Maître, Stn 1335; 22°19.7′ S, 166°26.6′ E; depth 20–24 m; 2 Dec. 1992; P. Bouchet, Campagne LAGON leg.; tubes d’Eunicidae avec épibiontes; MNHN • 1 specimen, dead; Ile Ouen-Baie du Prony, Stn 63; 22°26′ S, 166°26′ E; depth 20 m; 20 Aug. 1984; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Anse Vata ; 22°18.1′ S, 166°26.4′ E; depth 1–5 m; 1987–2007; Claude Berthault leg.; MNHN • 3 specimens, living; Île Ouen-Baie du Prony, Stn 66; 22°28′ S, 166°27′ E; depth 15 m; 20 Aug. 1984; B. Richer-ORSTOM leg.; MNHN • 5 specimens, living; Stn DE70; 22°25.6′ S, 166°31.0′ E; depth 20–21 m; 30 Apr. 1987; B. Richer de Forges-IRD leg.; MNHN • 5 specimens, living; Ile Ouen–Baie du Prony, Stn 84; 22°30′ S, 166°31′ E; depth 17 m; 21 Aug. 1984; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Stn DE36; 22°35.5′ S, 166°32.0′ E; depth 17–19 m; 29 Apr. 1987; B. Richer de Forges-IRD leg.; MNHN • 1 specimen, living; Ile Ouen-Baie du Prony, Stn 95; 22°31′ S, 166°33′ E; depth 14 m; 21 Aug. 1984; B. Richer-ORSTOM leg.; MNHN • 2 specimens, dead; Ile Ouen-Baie du Prony, Stn 99; 22°33′ S, 166°35′ E; depth 14 m; 21 Aug. 1984; B. Richer-ORSTOM leg.; MNHN • 1 specimen, living; Ile Ouen-Baie du Prony, Stn 100; 22°33′ S, 166°35′ E; depth 15 m; 21 Aug. 1984; B. Richer-ORSTOM leg.; MNHN • 1 specimen, living; Ile Ouen-Baie du Prony, Stn 101; 22°31′ S, 166°36′ E; depth 18 m; 21 Aug. 1984; B. Richer-ORSTOM leg.; MNHN • 8 specimens, living; Île Ouen–Baie du Prony, Stn 161; 22°34′ S, 166°38′ E; depth 20 m; 24 Aug. 1984; B. Richer-ORSTOM leg.; MNHN • 2 specimens, dead; Ile Ouen-Baie du Prony, Stn 226; 22°38′ S, 166°39′ E; depth 28 m; 22 Oct. 1984; B. Richer-ORSTOM leg.; MNHN • 1 specimen, living; Stn DE30; 22°35.8′ S, 166°39.6′ E; depth 12–13 m; 28 Apr. 1987; B. Richer de Forges-IRD leg.; MNHN • 1 specimen, living; Grand Récif Sud, Stn 293; 22°42′ S, 166°41′ E; depth 20 m; 26 Nov. 1984; B. Richer-ORSTOM leg.; MNHN • 1 specimen, living; Grand Récif Sud, Stn 291; 22°38′ S, 166°44′ E; depth 31 m; 26 Nov. 1984; B. Richer-ORSTOM leg.; MNHN • 1 specimen, living; Stn DE26; 22°32.3′ S, 166°46.5′ E; depth 20–22 m; 28 Apr. 1987; B. Richer de Forges-IRD leg.; MNHN • 3 specimens, living; Grand Récif Sud, Stn 304; 22°40′ S, 166°48′ E; depth 27 m; 27 Nov. 1984; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Grand Récif Sud, Stn 544; 22°51′ S, 166°49′ E; depth 25 m; 15 Jul. 1985; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Ile Ouen-Baie du Prony, Stn 150; 22°30′ S, 166°50′ E; depth 62–68 m; 24 Aug. 1984; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Grand Récif Sud, Stn 548; 22°56′ S, 166°55′ E; depth 32 m; 15 Jul. 1985; B. Richer-ORSTOM leg.; MNHN • 1 specimen, living; Grand Récif Sud, Stn 324; 22°24′ S, 167°03′ E; depth 39 m; 28 Nov. 1984; B. RicherORSTOM leg.; MNHN • 2 specimens, dead; Grand Récif Sud, Stn 405; 22°38′ S, 167°20′ E; depth 27 m; 23 Jan. 1985; B. Richer-ORSTOM leg.; MNHN. – Loyalty Islands • 1 specimen, dead; Lifou, Baie du Santal, ridge SE of Pointe Aimé Martin [= Acadro], Stn 1462; 20°47.1′ S, 167°03.2′ E; depth 70–120 m; 9 Nov. 2000; Atelier LIFOU 2000 leg.; dredged; MNHN .

Description ( Figs 39–40 )

SHELL. Robust, moderate to large for the genus (diameter up to 17.0 mm), globose-lenticular to trochoid-turbiniform (H/D 0.75–0.89); teleoconch of up to 7.0 whorls; periphery rounded, situated slightly below mid-whorl; suture level with or slightly above periphery, somewhat channelled on later spire whorls and slightly descendant immediately prior to insertion of outer lip; base umbilicate. Early teleoconch whorls with three primary spiral cords; uppermost cord beginning to define a shoulder during third whorl; secondary cords developing on shoulder and between primary cords during fourth whorl; cords subequal in strength at end of fifth whorl, crisply defined with triangular profile, 6–7 in number; limited subsequent intercalation of further cords, penultimate whorl with 8–9 cords; intervals between cords with fine, close-set spiral microlirae ( Fig. 40A ); axial sculpture of fine, close-set pliculae throughout, most obvious on mid-spire whorls ( Fig. 40B ), becoming coarser on last adult whorl; cord crests irregularly undulant rather than beaded; cord intervals with an additional intermediary on last adult whorl in some specimens; base with ±12 lower, more rounded spiral cords, progressively more distinctly beaded by axial pliculae toward umbilicus. Umbilicus of variable width, usually moderate to narrow, its margin defined by a broad thickened band with relatively coarse, curved, axial folds and faint, spiral threads; interior of umbilicus with broad funicle above which is a deep channel. Aperture roundly quadrate, peristome interrupted in parietal region; columella lip thick, with reflected lobe at end of umbilical funicle and thickened, somewhat granular pad at end of peri-umbilical band; a weak tooth often present at columella base; parietal region with thick, rounded lobe of callus adjacent to insertion of columella; outer lip simple, its edge scalloped by spiral cords, strongly prosocline above periphery, orthocline below; interior nacreous in live-collected specimens, lacking in-running spiral ridges, but with external sculpture evident through nacre.

COLOUR. Shell somewhat lustreless; colour pattern very variable; commonly mottled in shades of charcoal-grey, cream and white, often with subsutural and peripheral blotches and irregular axial bands; base usually less heavily pigmented; peri-umbilical band white to cream, sometimes with sparse reddish marks; lobe at end of umbilical funicle bright yellow in adults. Specimens from the Nouméa area often with more brownish and red/pink mottling. Occasional specimens with apical surface almost uniformly white save for a pink tip to spire.

DIMENSIONS. Holotype, height 12.7 mm, diameter 15.0 mm; largest specimen, diameter 17.0 mm.

PROTOCONCH ( Fig. 40C ). Typically umboniine, diameter ±195 µm; white; apical beak present and confluent with terminal lip; apical bulb sculptured with subradial threads, further subspiral threads evident towards suture, the two interacting to form a rectangular network; terminal lip weakly convex.

OPERCULUM ( Fig. 41A–B ) AND RADULA ( Fig. 41C–E ). As in T. apicina .

EXTERNAL ANATOMY (mostly from rehydrated specimens) ( Fig. 42 ). Head with distinct forehead between cephalic tentacles; snout moderately long, distal half with numerous slender papillae; cephalic lappets not evident; cephalic tentacles slender, micropapillate, left and right of more or less similar size; eyestalks thick, the tip of each conspicuously expanded and containing a large black eye; left neck-lobe with ± 12 digits, well developed anteriorly, progressively smaller posteriorly; right neck-lobe well developed, rolled to form a long exhalant siphon; four micropapillate epipodial tentacles on each side, with a stalked epipodial sense organ near base of each; a stalked epipodial sense organ also present beneath each neck-lobe; propodium indented in mid-line with a lateral propodial lobe on each side; foot flattened with broad sole, tapering posteriorly. Head-foot mostly whitish; forehead, snout and sides of foot with some darker pigmentation. Ctenidium bipectinate, its tip unattached.

Habitat

Most samples were obtained on the inner edge of the barrier reef, largely associated with sandy substrata; also in channels within the lagoonal system; living specimens at depths of 6–50 m, empty shells to 70 m.

Distribution ( Fig. 43 )

Known only from New Caledonia (Belep, Grande Terre and Lifou). Only one specimen has been found on Lifou, perhaps due to the absence of a lagoon around the island.

Remarks

Characters separating Talopena maestratii sp. nov. from the co-occurring T. apicina are given in the Remarks for the latter species. Although the distributions of the two species overlap extensively on Grande Terre and there are many samples available for both species, they have only been collected alive at the same station on five occasions. That T. maestratii has not been found on the Chesterfield-Bellona Plateau or the Lansdowne-Fairway Banks, and has been collected only once in the Loyalty Islands suggests that it favours sediments with a significant terrigenous component.

Talopena incerta (Iredale, 1912) , type species of the genus and evidently endemic to Raul Island in the Kermadec group, does not attain such a large size as T. maestratii sp. nov. (maximum diameter 14 mm fide Marshall 1979), and has fewer, more rounded primary spiral cords (only five above and including the periphery on the last adult whorl, Fig. 34D–G ).

Talopena calyculus ( Fig. 77A–C ) of unknown provenance is of similar size to T. maestratii sp. nov., but is more depressed, has weaker, less angular spiral cords, stronger axial sculpture between the cords, and a less prominent umbilical funicle with almost no reflection at the columella lip. Talopena belcheri ( Philippi, 1850) has been reported widely in the literature under the name Monilea belcheri (cf. Watson 1886: 71; Ladd 1966: 41; Cernohorsky 1972: 41, pl. 8 fig. 11; Tantanasiriwong 1978: 5, fig. 24; Fukuda 1993: 25, pl. 7 fig. 73, 1995: 35; Wilson 1993: 94, pl. 11 figs 20a–b; Higo et al. 1999: 67; Sasaki 2000: 83. fig. 135; Poppe et al. 2006: 108, pl. 57 figs 1–2; Poppe & Tagaro 2008: 198, pl. 44 figs 5, 8–9); however, the original description and figure of this species ( Philippi 1850: 148 and 1850 in 1846–1855: pl. 44 fig. 3) strongly suggest that it is referable to Talopena rather than Monilea . The original material was of unknown provenance, but was said to have come from the collection of Sylvanus Hanley. Attempts to trace this material in the NHMUK and the museums in Cambridge and Leeds have proved unsuccessful. In the absence of type material for comparison, T. belcheri is difficult to evaluate, but the figure shows a shell with a more depressed profile than T. maestratii , sparsely spotted with pink and with a reddish-brown peri-umbilical band.

The shell of T. masoni from the Andaman Islands is less elevated (H/D <0.70) than T. maestratii sp. nov., has very unequal spiral cords (of two or three orders) on the spire whorls and has a distinct narrow groove at the outer edge of the peri-umbilical band. T. menkei from the Philippines ( Fig. 77D–F ) has a more obviously beaded sculpture with less angular primary spiral cords and more distinct secondary cords in their intervals, and finer more numerous cords on the base. In T. philippii from ‘ China Seas’ the spiral sculpture is much less well developed and the umbilicus is more occluded by the reflected columella callus ( Fig. 77G–I ).

‘ Talopena ’ tramieri ( Poppe, Tagaro & Dekker, 2006) comb. nov.

Figs 44–46

Pseudominolia tramieri Poppe, Tagaro & Dekker, 2006: 109 , pl. 74 figs 1–4. Type locality: Caubian Island, Philippines.

Pseudominolia tramieri – Hasegawa 2018: 122, fig. 5m –n.

Material examined

NEW CALEDONIA – Plateau Chesterfield-Bellona • 1 specimen, dead; Plateau Chesterfield-Bellona, Stn D 50; 21°04.4′ S, 158°40.7′ E; depth 70 m; Jul. 1984; CHALCAL 1 leg.; MNHN . – Lansdowne-Fairway Banks • 1 specimen, dead; Bancs Lansdowne – Fairway, Stn D 9; 20°44.5′ S, 161°02′ E; depth

75 m; Jul. 1984; CHALCAL 1 leg.; MNHN • 1 specimen, dead; Bancs Lansdowne – Fairway, Stn D 10; 20°36.09′ S, 161°05.82′ E; depth 87 m; Jul. 1984; CHALCAL 1 leg.; MNHN. – Lagon Nord • 2 specimens, living; Stn 1174; 19°21′ S, 163°14′ E; depth 53 m; 31 Oct. 1989; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Stn 1168; 19°16′ S, 163°09′ E; depth 50 m; 30 Oct. 1989; B. RicherORSTOM leg.; MNHN • 4 specimens, living; Stn 1156; 19°10′ S, 163°13′ E; depth 55 m; 30 Oct. 1989; B. Richer-ORSTOM leg.; MNHN. – Grande Terre, Koumac • 1 specimen, dead; Chenal de la Passe de Koumac , Stn 1315; 20°40.7′ S, 164°14.7′ E; depth 66–87 m; Oct. 1993; Expédition Montrouzier leg.; sable coquillier vaseux; MNHN • 2 specimens, dead; Chenal de la Passe de Koumac , Stn 1323; 20°40.9′ S, 164°14.8′ E; depth 82–120 m; Oct. 1993; Expédition Montrouzier leg.; sable coquillier vaseux; MNHN • 1 specimen, dead; Passe de Koumac , east drop-off, Stn 1311; 20°40.4′ S, 164°14.9′ E; depth 10–60 m; Oct. 1993; Expédition Montrouzier leg.; fonds durs; MNHN • 1 specimen, dead; Passe Deverd, Stn 1322; 20°45.2′ S, 164°15.2′ E; depth 53–71 m; Oct. 1993; Expédition Montrouzier leg.; sable vaseux; MNHN. – Grande Terre, Touho • 3 specimens, living; Chenal au NE du Banc de Touho, Stn 1260; 20°44′ S, 165°14′ E; depth 49–59 m; Sep.1993; Expédition Montrouzier leg.; sable coquillier; MNHN • 2 specimens, dead; Chenal de Touho, Stn 1261; 20°46.5′ S, 165°15.75′ E; depth 45–56 m; Sep.1993; Expédition Montrouzier ; sable détritique; MNHN. – Grande Terre , Poindimié • 1 specimen, dead; Stn 788; 21°02′ S, 165°35′ E; depth 33 m; 9 Jan. 1987; B. Richer-ORSTOM leg.; MNHN • 2 specimens, dead; Stn 765; 21°14′ S, 165°42′ E; depth 35 m; 8 Jan. 1987; B. Richer-ORSTOM leg.; MNHN. – Grande Terre, Canala • 1 specimen, dead; Stn 730; 21°17′ S, 165°55′ E; depth 40–43 m; 12 Aug. 1986; B. Richer-ORSTOM leg.; MNHN • 1 specimen, living; Stn 713; 21°23′ S, 166°01′ E; depth 34–35 m; 11 Aug. 1986; B. Richer-ORSTOM leg.; MNHN • 1 specimen, living; Stn 714; 21°21′ S, 166°02′ E; depth 37–38 m; 11 Aug. 1986; B. Richer-ORSTOM leg.; MNHN. – Grande Terre, Thio • 1 specimen, dead; Stn 682; 21°34′ S, 166°19′ E; depth 36–37 m; 9 Aug. 1986; B. Richer-ORSTOM leg.; MNHN. – Grande Terre, Yaté • 1 specimen, dead; Stn 621; 22°01′ S, 166°53′ E; depth 55–56 m; 6 Aug. 1986; B. Richer-ORSTOM leg.; MNHN • 1 specimen, dead; Stn 620; 22°02′ S, 166°56′ E; depth 50–52 m; 6 Aug. 1986; B. Richer-ORSTOM leg.; MNHN. – Loyalty Islands • 2 specimens, dead; Lifou, Baie du Santal, ridge SE of Pointe Aimé Martin [= Acadro], Stn 1462; 20°47.1′ S, 167°03.2′ E; depth 70–120 m; 9 Nov. 2000; Atelier LIFOU 2000 leg.; dredged; MNHN .

Description ( Fig. 44 )

SHELL. Of moderate size (largest specimens 8–10 mm in diameter); spire whorls with 4–5 primary spiral cords (some intervals with a weaker intermediary cord) crossed by numerous fine, close-set, strongly prosocline axial threads. In addition, there are microscopic spiral lirae between the spiral cords; these interact with the axial threads to produce a fine, micro-granular sculpture – more obvious in some specimens than others. Base with finer, more close-set spiral sculpture. Umbilicus of moderate width and distinctive in having a strong, deep-set and relatively narrow spiral funicle that ends as a strong, tongue-shaped projection one quarter to one third of the way down columella. A deep, narrow channel separates this funicle from base of preceding whorl. A second, weaker, funicle lies just within rim of umbilicus, terminating as a more rounded projection near base of columella.

COLOUR. Pattern variable; usually pale, variously mottled with shades of yellow-ochre, with darker orange-yellow to brown blotches, particularly below suture; occasionally with a pinkish-orange wash in parts; spiral cords commonly flecked with white. Base paler and less boldly patterned; umbilicus whitish, upper funicle evidently never pigmented.

PROTOCONCH ( Fig. 45B ). Typically umboniine, diameter ±190 µm; apical beak present and confluent with terminal lip; apical bulb sculptured with an irregular, open network of threads, remainder with traces of subspiral threads; terminal lip weakly convex.

OPERCULUM ( Fig. 45C–D ). Corneous, multispiral; whorls relatively narrow, separated by a well-defined groove; peripheral fringe with faint radial striation; spiral microsculpture lacking.

RADULA ( Fig. 45E–F ). Formula ∞+ (1)+ 5+1+ 5+(1) +∞, with ± 45 transverse rows of teeth; teeth of central field reduced; rachidian base-plate broad, roundly quadrate its anterior edge recurved with vestige of shaft in centre; base-plates of inner lateral teeth expanded and bluntly rounded basally, outer anterior edge somewhat raised; outer laterals more quadrate. Innermost marginal transitional, with reduced shaft and cusp, and shouldered medial face; other marginal teeth well developed with narrow shaft and strongly recurved cusp; cusps of inner marginal teeth with large bluntly lanceolate central denticle bearing a small pointed denticle at its outer base and an even smaller, more slender one at inner base (usually not visible due to tooth overlap); marginals 3–10 with largest cusps; cusps progressively smaller thereafter, outermost ones with finely pectinate margins.

EXTERNAL ANATOMY (from rehydrated specimens). Limited detail evident; eyestalks well developed, their tips expanded and containing large black eyes; left neck-lobe digitate, digits perhaps branched; right neck-lobe well developed, margin entire, rolled to form an exhalant siphon; four micropapillate epipodial tentacles on left side, a similar number presumed on right. Epipodium and sides of foot densely speckled with pale pigmentation. Ctendium appearing bipectinate, its tip free.

Habitat

New Caledonian material mostly associated with the deeper regions of the lagoon and passes exiting the lagoon; at depths of 33–82 m (living 35–55 m).

Distribution ( Fig. 46 )

Previously known from the Philippines ( Poppe et al. 2006) and Ogasawara Islands ( Hasegawa 2018), here recorded also from the Chesterfield-Bellona Plateau, Lansdowne-Fairway Banks, Lagon Nord, Grande Terre and Loyalty Islands.

Remarks

Poppe et al. (2006) referred this species to Pseudominolia Herbert, 1992 , but did so only provisionally, pending further study. The presence of a distinct funicle in the umbilicus, and features of the radula (marginal teeth with spathulate cusps) and external anatomy (bipectinate ctenidium with unattached tip) are not consistent with referral to Pseudominolia . However, to which genus the species would be more appropriately referred is far from clear. The shell sculpture is not dissimilar to that of Kanakina glaphyrella gen. et comb. nov., but the eyestalks are long and the eyes large. The overall facies of the shell seem to be intermediate between Parminolia and Talopena . As an interim measure, pending the acquisition of molecular data, I have chosen to refer the species to Talopena , with which the radula morphology and external anatomy are largely consistent, on account of there being a strong funicle within the umbilicus and a thickened peri-umbilical band, albeit not as pronounced as in other Talopena species.

Differs from Talopena maestratii sp. nov. and T. apicina in having fewer, weaker and more widely-spaced spiral cords. In addition, the spire whorls are not so strongly shouldered and the suture is never sunken. Furthermore, in ‘ T ’. tramieri the umbilical funicle is stronger and more sharply defined, and the peri-umbilical band is less well developed. ‘ Ethalia ’ electra Herbert, 1992 from north-eastern South Africa is somewhat similar, but in that species the spiral cords are finer and more numerous, and the umbilical funicle is not as strongly developed.

Umboniinae — Group 2

Radula typically umboniine (formula ∞ +(1) +5+ 1+5 +(1) +∞), with reduced teeth in the central field, but in this group the cusps of the marginal radular teeth are not spathulate or lanceolate with a single elongate primary denticle, but rather more palmate or trigonal and the central denticle is not massively larger than the lateral denticles ( Figs 49D , 52D , 54F , 64F , 69E ). The genera Inkaba Herbert, 1992 and Pseudominolia Herbert, 1992 from the western Indian Ocean are also referable to this group.

Figures

Fig. 39. Talopena maestratii sp. nov. A–D. Holotype, Koumac, Stn 942, height 12.7 mm, diameter 15.0 mm (MNHN-IM-2000-38858). E–H. Large subadult specimen with slightly immature callus, Koumac, Stn 1304, diameter 16.9 mm (paratype, MNHN-IM-2000-38861).I–J. Subadult specimen with dense basal pigmentation, Koumac Stn KD518, diameter 13.6 mm (paratype, MNHN-IM-2000-38860). K–L. Specimen with reddish-brown pigmentation, Nouméa, Stn 546, diameter 12.7 mm (paratype, MNHN-IM-2000-38862).

Fig. 40. Talopena maestratii sp. nov. A. Detail of sculpture near start of last adult whorl showing microscopic spiral lirae between spiral cords, Koumac, Stn 1304 (paratype, MNHN-IM-2000-38861). B. Axial sculpture on spire, Touho, Stn 1251 (MNHN). C. Protoconch, Touho, Stn 1251 (MNHN). Scale bars: A–B =0.5 mm; C =100 µm.

Fig. 41. Talopena maestratii sp. nov. A. Operculum.B. Detail of operculum sculpture. C. Radula, central field and inner marginal teeth. D. Latero-marginal transition showing reduced cusp of innermost marginal tooth. E. Spathulate inner marginal teeth. A–B. Koumac, KD518 (paratype, MNHN-IM-2000-38860). C–E. Nouméa, Stn 161 (MNHN). Scale bars: A=1.0 mm; B=0.5 mm; C= 100 µm; D–E =50 µm.

Fig. 42. Talopena maestratii sp. nov., living animal (subadult), Koumac, Stn KD578, shell diameter approx. 12 mm, image Philippe Maestrati (PM751) (paratype, MNHN- IM-2019-9732).

Fig. 43. Map of New Caledonia showing the distribution of Talopena maestratii sp. nov. Type locality indicated in pink.

Fig. 34. Comparison of Monilea Swainson, 1840 and Talopena Iredale, 1918. A–C. Monilea callifera (Lamarck, 1822), holotype ofTrochus calliferus Lamarck, 1822 (MHNG-MOLL-51504), height 10 mm, diameter 19 mm (images courtesy of Emmanuel Tardy). D–G. Talopena incerta (Iredale, 1912), holotype of Monilea incerta Iredale, 1912 (CMNZ M2755), height 7.8 mm, diameter 9.5 mm (not 10 ×9 mm as given by Iredale) (images courtesy of Paul Scofield and Mark Fraser).

Fig. 77. Specimens examined and illustrated for comparison.A–C. Figured syntype of Trochus calyculus W. Wood, 1828, diameter 17.1 mm (NHMUK 1878.6.3.1).D–F. Holotype of Monilea menkei A. Adams, 1855, diameter 15.5 mm (NHMUK 1968180). G–I. Lectotype of Monilea philippii A. Adams 1855, diameter 15.0 mm, designated by Herbert (1992: 449) (NHMUK 1968181). Images courtesy of Kevin Webb, NHM Photo Unit. © The Trustees of the Natural History Museum, London.

Fig. 44. ‘Talopena’tramieri (Poppe, Tagaro & Dekker, 2006) (all MNHN). A–D. Lagon Nord, Stn 1156, height 6.0 mm, diameter 8.5 mm. E. Canala, Stn 713, height 7.3 mm, diameter 9.0 mm. F. Thio, Stn 682, diameter 7.2 mm.

Fig. 45. ‘Talopena’ tramieri (Poppe, Tagaro & Dekker, 2006) (all MNHN). A. Sculpture of apical whorls. B. Protoconch. C. Operculum. D. Detail of operculum lacking spiral microsculpture. E. Radula, entire width. F. Radula, latero-marginal transition. A–B. Canala, Stn 730. C–F. Belep, Stn 1156. Scale bars: A=0.5 mm; B, F =50 µm; C=1.0 mm; D–E =100 µm.

Fig. 46. Map of the Coral Sea showing the distribution of ‘Talopena’ tramieri (Poppe, Tagaro & Dekker, 2006) in the New Caledonian marine ecoregion.

Fig. 49. Ethaliella rhodomphala (Souverbie, 1875), radula (all MNHN). A. Entire width of radula, Koumac, Stn 1306.B. Oblique view of latero-marginal transition, Koumac, Stn 1306. C. Marginal series, Koumac, Stn KD574. D. Inner marginal teeth, Koumac, Stn 1306. Scale bars: A=50 µm; B=25 µm; C–D =20 µm.

Fig. 52. Ethminolia probabilis Iredale, 1924, operculum and radula, Twofold Bay, New South Wales (NMW 1955.158). A. Entire operculum. B. Microsculpture of operculum. C–G. Radula. Scale bars: A=0.5 mm; B=100 µm; C, E= 25 µm; D, F–G=20 µm.

Fig. 54. Ethminolia hickmanae sp. nov. A. Oblique view of apex. B. Protoconch. C–D. Operculum. E–F. Radula. A–B. Koumac, Stn KD545. C–F. Nouméa, Stn 1345 (paratype, MNHN-IM-2000-38866). Scale bars: A, C =200 µm; B =50 µm; D–E=50 µm; F =10 µm.

Fig. 64. Tylorhaphe luteopicta gen. et sp. nov. A. Oblique view of apical whorls. B. Protoconch. C. Operculum. D. Detail of operculum showing microscopic spiral sculpture. E. Radula, half row. F. Radula, latero-marginal transition. A–B. Solomon Islands, north of Malaita, Stn DW1768 (paratype, MNHN-IM-2000-38877). C–F. New Caledonia, south of Île des Pins, Stn CP4674 (paratype, MNHN- IM-2000-38876). Scale bars: A=1.0 mm; B, E =50 µm; C=0.5 mm; D= 100 µm; F =20 µm.

Fig. 69. Vanitrochus semiustus (Fischer, 1879) (all MNHN). A. Oblique view of apical whorls. B. Protoconch. C. Operculum. D. Detail of operculum to show microscopic spiral threads. E. Radula half row. F. Radula, oblique view of later-marginal transition. A–B. Koumac, Stn KD557. C–F. Ouégoa, Stn KD590. Scale bars: A= 250 µm; B, D =100 µm; C=200 µm; E= 10 µm; F =20 µm.