taxonID	type	description	language	source
EF59879A40131C1710E2FE78FC3DFCC2.taxon	description	(Figs 2 A – C; 3; Table 1)	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40131C1710E2FE78FC3DFCC2.taxon	materials_examined	Type locality. Ofu Island, Samoan Islands. Type material. Holotype: TheNAT 23763, Paratype: BPBM 196191. Other material. South China Sea (East Sea), Spratly Islands (Truong Sa Islands), Khanh Hoa Province, Vietnam: Lansdowne Reef (Len Dao Island), on dead corals and un- der stones, 09 ° 46 ’ 37 ’’ N, 114 ° 22 ’ 34.8 ’’ E, depth 10 m, coll. Tai-Tu N., 19.5.2019, VRTCM. Ga 27051619.01 (3 shells); Pearson Reef (Phan Vinh Island), on dead corals and under stones, 08 ° 57 ’ 24.1 ’’ N, 113 ° 41 ’ 31.2 ’’ E, depth 18 – 21 m, coll. Tai-Tu N., 23.5.2019, VRTCM. Ga 27050619.01 (4 shells); Barque Canada Reef (Thuyen Chai Island), on dead corals and under stones, 08 ° 16 ’ 35.3 ’’ N, 113 ° 21 ’ 10.7 ’’ E, depth 12 m, coll. Tai-Tu N., 29.5.2019, VRTCM. Ga 27051019.01 (2 shells); on dead corals and under stones, 08 ° 16 ’ 54.4 ’’ N, 113 ° 21 ’ 51.8 ’’ E, depth 8 – 9 m, coll. Tai-Tu N., 30.10.2020, VRTCM. Ga 27051020.01 (5 shells); Alison Reef (Toc Tan Island), on dead corals and under stones, 08 ° 49 ’ 7.04 ’’ N, 113 ° 57 ’ 6.73 ’’ E, depth 2 m, coll. Tai-Tu N., 25.5.2019, VRTCM. Ga 27050719.01 (3 shells); Namyit Island (Nam Yet Island), on dead corals and under stones, 10 ° 11 ’ 03.8 ’’ N, 114 ° 22 ’ 05.2 ’’ E, depth 16 – 18 m, coll. Tai-Tu N., 11.10.2020, VRTCM. Ga 27051920.01 (4 shells).	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40131C1710E2FE78FC3DFCC2.taxon	diagnosis	Diagnosis. The shell is rather long, cyrtoconoid, with flat profile of upper whorls and convex of lower ones. First few teleoconch whorls white, subsequent whorls smoky gray to yellowish brown; protoconch yellowish brown. Protoconch of 6 whorls, first whorl has hemispherical granules, whorls 2 – 4 have 1 median spiral thread, whorls 5 – 6 have 2 median spiral threads, uninterrupted by axial riblets on protoconch whorls. Teleoconch of up to 13 whorls with three smooth spiral cords. The first and third spiral cords are granulated on the upper 4 teleoconch whorls. The second spiral cord is smooth and appears on the seventh teleoconch whorl. Spiral microsculpture of fine threads between the main spiral cords. Base with two additional weakly tuberculed spiral cords and one spiral cord with microsculpture of fine threads. Peristome with an additional rather smooth spiral cord (Fig. 3 D, Sp 1). Outer lip rather thick and flared. Anterior siphonal canal oblique, subtubular, rather long (Figs 2, 3).	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40131C1710E2FE78FC3DFCC2.taxon	description	Dimensions. SH: 4.3 – 6.9 mm; SW: 1.4 – 2.1 mm.	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40131C1710E2FE78FC3DFCC2.taxon	distribution	Distribution. In Vietnam, known from Lansdowne Reef, Pearson Reef, Barque Canada Reef, Alison Reef, Namyit Island of the Spratly Islands. Elsewhere: Samoan Islands, Philippines, Hawaii, Polynesia Islands, Kiribati, Gulf of Aqaba, Taiwan, Marshall Islands, Christmas Island [Baker, Spicer, 1935; Poppe, 2008; Dan, 2020; Bakker, Albano, 2022; Albano et al., 2023].	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40131C1710E2FE78FC3DFCC2.taxon	discussion	Remarks. Viriola abbotti differs from V. incisa in its smoky gray to yellowish brown shell (vs. purplish red shell); spiral microsculpture of fine threads between the main spiral cords (vs. smooth). V. abbotti differs from V. cancellata in having spiral microsculpture of fine threads between the main spiral cords (vs. spiral microsculpture of fine threads and weakly axial riblets); First few teleoconch whorls white, subsequent whorls smoky gray to yellowish brown (vs. The shell yellowish brown with white blotches on the first spiral cord, white granules on the second spiral cord, and reddish brown between spiral cords 1 – 3).	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40131C161375FCCCFB55F87F.taxon	description	(Figs 2 G – J; 4; Table 1)	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40131C161375FCCCFB55F87F.taxon	materials_examined	Type locality. New Caledonia Island, southwest Pacific Ocean. Type material. Syntype: MNHN-IM- 2000 - 1388. Other material. South China Sea, Spratly Islands, Khanh Hoa Province, Vietnam: Southwest Cay Island, on dead corals and under stones, 11 ° 26 ’ 11.8 ” N 114 ° 19 ’ 56.3 ” E, depth: 5 – 8 m, coll. Tai-Tu N., 6.10.2020, VRTCM. Ga 27051220.01 (1 shell).	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40131C161375FCCCFB55F87F.taxon	diagnosis	Diagnosis. The shell is narrowly conical, long with flat sides. Teleoconch brown to reddish brown with white blotches on the main spiral cords. Teleoconch whorls with three smooth spiral cords. The second spiral cord, developing later, presents as a string of granules in the early teleoconch. Prosocline axial ribs between the main spiral cords. The last whorl has 24 – 26 axial ribs. Base with three additional smooth spiral cords (Fig. 4 C, S 1 - S 3). Peristome with an additional tuberculed spiral cord (Fig. 4 D, Sp 1). Outer lip thick and flared. Parietal callus thick. Anterior siphonal canal oblique, subtubular, long. Protoconch missing.	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40131C161375FCCCFB55F87F.taxon	description	Dimensions. SH: 7.8 mm; SW: 2.0 mm (protoconch missing).	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40131C161375FCCCFB55F87F.taxon	distribution	Distribution. In Vietnam known from Southwest Cay Island of the Spratly Islands. Elsewhere: New Caledonia, Philippines, Israel, Crete Island, Astypalaia Island, Greece, Turkey, Cyprus, Hawaii, Marshall Islands [Jousseaume, 1884; Poppe, 2008; Steger et al., 2018; Angelidis, Polyzoulis, 2018; Albano et al., 2021; Bakker, Albano, 2022; Albano et al., 2023].	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40131C161375FCCCFB55F87F.taxon	discussion	Remarks. V. bayani differs from V. senafirensis (Sturani, 1903) in its long, narrowly conical shell, with flat sides (vs. shell short, cyrtoconoid, with convex sides). V. bayani differs from V. corrugata in having a brown shell with white streaks on the spiral cords (vs. yellowish brown); the last whorl has 24 – 26 axial ribs (vs. 34 – 36 axial ribs).	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40141C1D1120F905FAC7F87D.taxon	description	(Figs 2 D – F, 5; Table 1) Zoobank registration: urn: lsid: zoobank. org: act: 0971 EF 73 - B 78 E- 484 E- 9 A 37 - 2 FB 6710001 F 8	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40141C1D1120F905FAC7F87D.taxon	materials_examined	Type locality: Namyit Island, Spratly Islands, Khanh Hoa province, Vietnam, 10 ° 11 ’ 03.8 ’’ N, 114 ° 22 ’ 05.2 ’’ E, depth 16 – 18 m. Type material. Holotype VNMN M- 000.002.348 (shell height 7.4 mm, shell width 2.1 mm, Figs. 2 D – E). Paratype: VRTCM. Ga 27050719.03 (1 shells), Tai-Tu N. (14 shells), same data as holotype.	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40141C1D1120F905FAC7F87D.taxon	etymology	Etymology: This species is named after the type locality, Namyit Island, Spratly Islands, Khanh Hoa province, Vietnam.	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40141C1D1120F905FAC7F87D.taxon	materials_examined	Material examined. South China Sea, Spratly Islands, Vietnam: Lansdowne Reef, on dead corals and under stones, 09 ° 46 ’ 37 ’’ N, 114 ° 22 ’ 34.8 ’’ E, depth 10 m, coll. Tai-Tu N, 19.5.2019, VRTCM. Ga 27051619.02 (3 shells); Pearson Reef, on dead corals and under stones, 08 ° 57 ’ 24.1 ’’ N, 113 ° 41 ’ 31.2 ’’ E, depth 18 – 21 m, coll. Tai-Tu N, 23.5.2019, VRTCM. Ga 27050619.02 (1 shell); Barque Canada Reef, on dead corals and under stones, 08 ° 16 ’ 35.3 ’’ N, 113 ° 21 ’ 10.7 ’’ E, depth: 12 m, coll. Tai-Tu N., 29.5.2019, VRTCM. Ga 27051019.02 (2 shells); on dead corals and under stones, 08 ° 15 ’ 52.2 ’’ N, 113 ° 21 ’ 45.5 ’’ E, depth: 6 – 8 m, coll. Tai-Tu N, 29.10.2020, VRTCM. Ga 27051020.02 (2 shells); on dead corals and under stones, 08 ° 16 ’ 54.4 ’’ N, 113 ° 21 ’ 51.8 ’’ E, depth: 8 – 9 m, coll. Tai-Tu N., 30.10.2020, VRTCM. Ga 27051020.03 (3 shells); Alison Reef, on dead corals and under stones, 08 ° 49 ’ 7.04 ’’ N, 113 ° 57 ’ 6.73 ’’ E, depth: 2 m, coll. Tai-Tu N, 25.5.2019, VRTCM. Ga 27050719.02 (2 shells); on dead corals and under stones, 08 ° 49 ’ 47.8 ’’ N, 113 ° 56 ’ 3.2 ’’ E, depth: 3 m, coll. Tai-Tu N, 27.5.2019, VRTCM. Ga 27050719.03 (3 shells).	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40141C1D1120F905FAC7F87D.taxon	diagnosis	Diagnosis. The shell is rather long, cyrtoconoid, flat above and convex below. The teleoconch is yellowish brown with white blotches on the first spiral cord, white granules on the second spiral cord, and reddish brown between spiral cords 1 – 3. The first whorl of protoconch has numerous hemispherical granules. Teleoconch has 13 whorls, with three spiral cords. The second spiral cord is weakly granular, appearing on the first teleoconch whorl. Spiral microsculpture of fine threads and weakly axial riblets that are present between the main spiral cords. The last whorl has 34 – 36 axial ribs. Base with two additional weakly tuberculed spiral cords (Fig. 5 C, S 1 – S 2).	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40141C1D1120F905FAC7F87D.taxon	description	Description. The shell is rather long, cyrtoconoid, flat above and convex below. The teleoconch is yellowish brown with white blotches on the first spiral cord, white granules on the second spiral cord, and reddish brown between spiral cords 1 – 3; protoconch reddish brown. The protoconch has 6 whorls, the first whorl with hemispherical granules, whorls 2 – 4 with one median spiral thread, and whorls 5 – 6 with 2 median spiral threads, uninterrupted axial riblets on protoconch whorls. Teleoconch has 13 whorls, with three spiral cords. First and third spiral cords are smooth, granulated on the first teleoconch whorl. The second spiral cord is weakly granular, appearing on the first teleoconch whorl. Spiral microsculpture of fine threads and weakly axial riblets that are present between the main spiral cords. The last whorl has 34 – 36 axial ribs. Base with two additional weakly tuberculed spiral cords (Fig. 5 C, S 1 – S 2). Peristome with an additional tuberculed spiral cord (Fig. 5 D, Sp 1). Outer lip thick and flared. Anterior siphonal canal oblique, subtubular, long. Measurements. SH: 7.4 – 8.4 mm; SW: 2.1 – 2.5 mm (n = 2).	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40141C1D1120F905FAC7F87D.taxon	distribution	Distribution. This species is known from Spratly Islands, Khanh Hoa province, Vietnam.	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40141C1D1120F905FAC7F87D.taxon	biology_ecology	Ecology. This species collected under stones and on dead corals.	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40141C1D1120F905FAC7F87D.taxon	discussion	Remarks. Viriola namyitensis n. sp. is superficially similar to V. cancellata (Hinds, 1843). However, V. namyitensis n. sp. differs from V. cancellata in having the shell cyrtoconoid, flat above, convex below, base rather wide (vs. the shell cyrtoconoid with flat sides); the first whorl of protoconch has numerous hemispherical granules (vs. the first two whorls of protoconch have numerous hemispherical granules); the second spiral cord appears on the first teleoconch whorl (vs. the second spiral cord appears on the second teleoconch whorl); spiral microsculpture of fine threads and axial ribs (vs. axial ribs); the last whorl has 34 – 36 axial ribs (vs. 28 – 30 axial ribs); the base with two additional weakly tuberculed spiral cords (vs. the base with an additional granulated spiral cord and a small, smooth spiral cord).	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40181C1C10DDFF26FDEBF9F0.taxon	description	(Figs 2 K – N, 6; Table 1)	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40181C1C10DDFF26FDEBF9F0.taxon	description	Dumrongrojwattana et al., 2016: 286, fig. 3 V.	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40181C1C10DDFF26FDEBF9F0.taxon	materials_examined	Type locality. Lifou Island, New Caledonia. Type material. Syntype: MNHN-IM- 2000 - 1314. Other material. South China Sea, Spratly Islands, Vietnam: Barque Canada Reet, on dead corals and under stones, 08 ° 16 ’ 35.3 ’’ N, 113 ° 21 ’ 10.7 ’’ E, depth: 12 m, coll. Tai-Tu N., 29.5.2019, VRTCM. Ga 27051019.03 (2 shells); Namyit Island, on dead corals and under stones, 10 ° 11 ’ 03.8 ’’ N, 114 ° 22 ’ 05.2 ’’ E, depth: 16 – 18 m, coll. Tai-Tu N., 11.10.2020, VRTCM. Ga 27051920.03 (1 shell).	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40181C1C10DDFF26FDEBF9F0.taxon	diagnosis	Diagnosis. The shell is short, cyrtoconoid. First few teleoconch whorls are white, subsequent whorls white with brown streaks; protoconch reddish brown. Protoconch of 6 whorls, first whorl with hemispherical granules, whorls 2 – 4 have 1 median spiral thread, whorls 5 – 6 have 2 median spiral threads, uninterrupt- ed axial riblets on protoconch whorls. Teleoconch has 8 – 9 whorls, with three spiral cords. The first and third spiral cords are smooth, appearing as granulated spiral cords on the first 3 teleoconch whorls. The second spiral cord is granular, developing later on the fifth teleoconch whorl. Spiral microsculpture of strings of granules and axial ribs between the main spiral cords. The last whorl has 22 – 24 axial ribs. Base with an additional granulated spiral cord and a small, smooth spiral cord. Peristome with an additional tubercled spiral cord. Outer lip rather thin and flared. Anterior siphonal canal oblique, subtubular, rather short (Figs 2 K – N, 6).	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40181C1C10DDFF26FDEBF9F0.taxon	description	Dimensions. SH: 3.8 – 3.9 mm; SW: 1.2 – 1.3 mm.	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40181C1C10DDFF26FDEBF9F0.taxon	distribution	Distribution. In Vietnam, known from Barque Canada Reet, Namyit Island of the Spratly Islands. Elsewhere: Christmas Island, Cocos Islands, Polynesia, Japan, Marshall Islands, New Caledonia, Kermadec Islands, Philippines, Taiwan, Thailand [Bakker, Albano, 2022; Albano et al., 2023].	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40181C1C10DDFF26FDEBF9F0.taxon	discussion	Remarks. The specimens collected in this study are smaller in size than the syntype (MNHN- IM- 2000 - 1314). Viriola intergranosa is superficially similar to Viriola thochuensis n. sp.	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40181C1F1121F90DFB18F925.taxon	description	(Figs 2 O – U, 7; Table 1) Zoobank registration: urn: lsid: zoobank. org: act: 591 BB 4 BE- 3 E 3 A- 4 E 36 - 8 C 2 D-AF 6 B 93055085	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40181C1F1121F90DFB18F925.taxon	materials_examined	Type material. Holotype VNMN M- 000.002.349 (shell height 6.2 mm, shell width 2.2 mm, Figs. 2 S – T). Paratypes: VRTCM. Ga 27051019.04 (4 shells), Tai-Tu N. (10 shells), same data as holotype. Type locality: Hon Xanh Island, Tho Chu Islands, Kien Giang province, Vietnam, 09 ° 16 ’ 45.4 ’’ N, 103 ° 29 ’ 16.0 ’’ E, depth 12 m.	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40181C1F1121F90DFB18F925.taxon	etymology	Etymology: This species is named after the type locality, where the type species was found Tho Chu Islands, Kien Giang province, Vietnam.	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40181C1F1121F90DFB18F925.taxon	materials_examined	Material examined. South China Sea, Spratly Islands, Khanh Hoa Province, Vietnam: Barque Canada Reet, on dead corals and under stones, 08 ° 16 ’ 35.3 ’’ N, 113 ° 21 ’ 10.7 ’’ E, depth: 12 m, coll. Tai-Tu N., 29.5.2019, VRTCM. Ga 27051019.04 (2 shells); on dead corals and under stones, 08 ° 16 ’ 54.4 ’’ N, 113 ° 21 ’ 51.8 ’’ E, depth: 8 – 9 m, coll. Tai-Tu N., 30.10.2020, VRTCM. Ga 27051019.05 (3 shells); Namyit Island, on dead corals and under stones, 10 ° 11 ’ 03.8 ’’ N, 114 ° 22 ’ 05.2 ’’ E, depth: 16 – 18 m, coll. Tai-Tu N., 11.10.2020, VRTCM. Ga 27051920.04 (2 shells); Tho Chu Islands, Kien Giang Province, Vietnam: Hon Xanh Island, on dead corals and under stones, 09 ° 16 ’ 45.4 ’’ N, 103 ° 29 ’ 16.0 ’’ E, depth: 12 m, coll. Tai-Tu N., 13.6.2023, VRTCM. Ga 38080923.02 (7 shells).	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40181C1F1121F90DFB18F925.taxon	diagnosis	Diagnosis. The shell is short, conoid, rather flat sides, base wide. Protoconch has 5 – 5 ½ whorls. Teleoconch has 8 – 9 whorls, with three spiral cords. The first and third spiral cords are smooth, appearing as granulated spiral cords on the first 2 teleoconch whorls. The second spiral cord is granular, developing later on the second teleoconch whorl. Spiral microsculpture of fine threads and axial ribs between the main spiral cords. The last whorl has 26 – 28 axial ribs. The shell has a white background with patches of brown to dark brown. The third spiral cord on the teleconch whorls is more brightly colored than the first and second spiral cords.	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40181C1F1121F90DFB18F925.taxon	description	Description. The shell is short, conoid, rather flat sides, base wide. The shell has a white background with patches of brown to dark brown. The third spiral cord on the teleconch whorls is more brightly colored than the first and second spiral cords. Protoconch is reddish brown, with 5 – 5 ½ whorls. First protoconch whorl has hemispherical granules; protoconch whorls 2 – 3 have one median spiral thread, protoconch whorls 4 – 5 ½ have 2 median spiral threads; uninterrupted axial riblets on protoconch whorls. Teleoconch has 8 – 9 whorls, with three spiral cords. The first and third spiral cords are smooth, granulated on the first 2 teleoconch whorls. The second spiral cord is granular, developing later on the second teleoconch whorl. Spiral microsculpture of fine threads and axial ribs between the main spiral cords. The last whorl has 26 – 28 axial ribs. Base with an additional granulated spiral cord (Fig. 7 C, S 1) and a small, smooth spiral cord (Fig. 7 C, S 2). Peristome with an additional tuberculed spiral cord (Fig. 7 D, Sp 1). Aperture sub- quadrate. Outer lip rather thick and flared. Anterior siphonal canal oblique, subtubular, rather short. Measurements. Shell height 3.6 – 6.3, shell width 1.1 – 2.2 (n = 14).	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40181C1F1121F90DFB18F925.taxon	distribution	Distribution. This species is known from Tho Chu islands and Spratly Islands islands.	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40181C1F1121F90DFB18F925.taxon	biology_ecology	Ecology. This species collected under stones and on dead corals.	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
EF59879A40181C1F1121F90DFB18F925.taxon	discussion	Remarks. Viriola thochuensis n. sp. is superficially similar to V. intergranosa. However, V. thochuensis n. sp. differs from V. intergranosa in having the shell short, conoid, with rather flat sides, base rather wide (vs. the shell short, cyrtoconoid); protoconch with 5 – 5 ½ whorls (vs. 6 whorls); the first and third spiral cords appeared as granulated spiral cords on the first 2 teleoconch whorls (vs. appeared as granulated spiral cords on the first 3 teleoconch whorls); the second spiral cord appears on the second teleoconch whorl (vs. appears on the fifth teleoconch whorl); spiral microsculpture of fine threads and axial ribs (vs. strings of granules and axial ribs); the last whorl has 26 – 28 axial ribs (vs. 22 – 24 axial ribs); outer lip rather thick (vs. rather thin).	en	Nguyen, Tai-Tu, Hoang, Duong T. T. (2025): Description of new species of the genus Viriola Jousseaume, 1884 (Gastropoda: Triphoridae) from Vietnam. Ruthenica, Russian Malacological Journal 35 (2): 53-64, DOI: 10.35885/ruthenica.2025.35(2).1, URL: https://doi.org/10.35885/ruthenica.2025.35(2).1
