taxonID	type	description	language	source
038A8132EE66ED4BFEEACBF6FF11F91F.taxon	materials_examined	Type genus: Eopilidion gen. nov. Diagnosis: Pilidiophorans with extremely reduced precerebral region; proboscis pore opening just in front of brain.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE66ED4BFC55CEB9FC37FDE5.taxon	materials_examined	Type species: Eopilidion misakiense sp. nov., fixed by original designation. Diagnosis: At the moment, the same as for the family. Etymology: The new genus name is neuter in gender, from the Greek ἠώς (eos, ‘ dawn’) and πιλίδιον (pilidion, ‘ small hat’).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE66ED48FC4ECCF3FB5FF8E5.taxon	description	(FIGS 2 A, 4 A – C) Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org: act: DBA 0 D 4 FA-ACAC- 4440 - 9 EA 3 - 894 F 582 D 62 F 0. Material examined: Holotype, ICHUM 6303, extracted total DNA (no morphological voucher remains); 12 February 2015, dredged at station 2 of the 5 th JAMBIO Coastal Organism Joint Survey (Nakano et al., 2015), off Misaki (between 35 ° 08 ′ 29 ′ N, 139 ° 32 ′ 34 ″ E, 198 m depth, and 35 ° 08 ′ 27 ″ N, 139 ° 32 ′ 12 ″ E, 274 m depth), Sagami Bay, Kanagawa, Japan, collected by H. Kajihara. Sequences: From the holotype: LC 178608, 18 S (1768 bp); LC 178641, 28 S (2144 bp); LC 178690, 16 S (506 bp); LC 190962, COI (658 bp). Etymology: The new specific name is an adjective, derived from the type locality. Description: Known from anterior fragment, 4 mm long, 1 mm wide, uniformly pale red in colour. Head anteriorly pointed (Fig. 2 A), similar to that of capitellid polychaetes. Pre-cerebral region remarkably reduced, about 200 µm long, 320 µm in diameter at base; brain region 500 µm long, 700 µm wide. Transverse cephalic furrow present just behind brain (Fig. 4 A, C), encircling head, without secondary furrows. Cerebral organ just behind cephalic furrow, elongated pit, 380 µm long along anterior – posterior axis, 130 µm wide along dorsoventral axis (Fig. 4 C). Mouth ventral, small, opening 1.6 mm behind tip of head. Proboscis pore opening subterminal (Fig. 4 A – C), immediately anterior to brain. enlargement of the head (K); L, M, Baseodiscus aff. princeps (Coe, 1901 a), ICHUM 6335, entire body (L) and enlargement of the head (M); N, Baseodiscus nipponensis (Hubrecht, 1887), ICHUM 6338; O – Q, Baseodiscus cf. princeps (Coe, 1901 a), ICHUM 6339, entire body (O), ventral view of anterior end (P), and lateral view of head (Q). Photos by A. V. Chernyshev (A, B), H. Kajihara (C – F, N – Q), G. Giribet (G, H), T. C. Hiebert (I), and K. Kakui (J, K, L, M). Distribution: Known only from the type locality, Sagami Bay, Japan. Remarks: The unusually reduced precerebral region and the wide subventral proboscis pore opening just in front of the brain, as well as phylogenetic position as sister-taxon to all other molecularly known heteronemerteans, justify a new family for E. misakiense. However, information on the body-wall structure is lacking, and it remains to be determined whether Eopilidion misakiense belongs to the Heteronemertea (with cutis layer) or not (without cutis layer) (see Discussion below).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE64ED49FED3CF6CFDEFFBA9.taxon	description	Heteronemertea sp. 2 DS: Chernyshev & Polyakova, 2018, fig. 1 E. Sequences: MF 512067, 18 S (1766 bp); MF 512093, 28 S (505 bp); MF 512135, H 3 (331 bp); MF 512042, 16 S (512 bp). Determined by Chernyshev & Polyakova (2018). Remarks: The material was collected at station 1 - 9 of the 2015 SokhoBio expedition, 3307 m depth, Sea of Okhotsk (46 ° 08.8 ′ N, 146 ° 00.0 ′ E). HETERONEMERTEA SP. 5 DS Heteronemertea sp. 5 DS: Chernyshev & Polyakova, 2018, figs 1 D, 4 A. Sequences: MF 512069, 18 S (1779 bp); MF 512095, 28 S (862 bp); MF 512137, H 3 (180 bp); MF 512044, 16 S (390 bp). Determined by Chernyshev & Polyakova (2018). Remarks: The material was collected at station 5 - 9 of the 2015 SokhoBio expedition, 1699 m depth, Sea of Okhotsk (48 ° 37.2 ′ N, 150 ° 00.3 ′ E).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE64ED49FCD2CB71FAFDFA6F.taxon	materials_examined	Type species: Oxypolella punnetti Bergendal, 1902, fixed by monotypy. Diagnosis: Given by Cantell (2005: 124).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE64ED49FF4AC8DEFC2EFB1C.taxon	materials_examined	Type species: Sonnenemertes cantelli Chernyshev et al., 2015, fixed by original designation. Diagnosis: Given by Chernyshev et al. (2015: 121). SONNENEMERTES CANTELLI CHERNYSHEV ET AL., 2015	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE64ED49FF4AC8DEFC2EFB1C.taxon	materials_examined	Material sequenced: A tissue subsample from the holotype, MIMB 28684, 3 August 2012, about 400 km south of the Kamchatka Peninsula (46 ° 13.69 ′ – 46 ° 14.87 ′ N, 155 ° 33.29 ′ – 155 ° 32.49 ′ E), north-west Pacific, Agassiz trawl, 4869 – 4861 m depth, station 2 - 11 of the KuramBio expedition with the S / V Sonne, collected by A. V. Chernyshev. Sequences: From the holotype: LC 178609, 18 S (1795 bp); LC 178642, 28 S (2094 bp); LC 190963, COI (658 bp) (determined in this study). AB 921565, 16 S (505 bp), determined by Chernyshev et al. (2015), also from the holotype. Distribution: Known from depths of 3306 – 4861 m around the Kuril Islands in the Sea of Okhotsk and the north-west Pacific (Chernyshev et al., 2015; Chernyshev & Polyakova, 2018). Remarks: Sonnenemertes cantelli is ‘ 12 – 14 mm long, cylindrical and stout, with rounded anterior and posterior ends, without caudal cirrus; body yellowish in anterior part and pinkish in gut region’ (Chernyshev & Polyakova, 2018: 124). The species seems to feed on sipunculans (see Potential food items below).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE64ED49FF3ECA20FD6AF990.taxon	description	Eupoliaidae [sic] Hubrecht, 1887: 10.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE64ED49FF3ECA20FD6AF990.taxon	description	Oxypolellinae Chernyshev, 1995: 14 (synonymous when placed at the rank of family). Diagnosis: Pilidiophorans without horizontal lateral cephalic slits; transverse cephalic furrows present or absent; proboscis without pseudocnidae, mostly lacking muscle crosses; one or no frontal organ (as opposed to three frontal organs in Lineidae).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE64ED56FC73C866FDF5FE53.taxon	distribution	Distribution: Sweden (Bergendal, 1903; Sundberg & Saur, 1998). Remarks: Strand et al. (2010: 115) summarized the species with, ‘ Length up to 5 cm. Body white and glossy, circular in cross section, not tapering posteriorly (apex rounded), typically contracted and held in an arched posture. Skin thick, wax-like and slightly wrinkled. Head eye-less and pointed, without horizontal lateral cephalic slits, but demarcated by a transverse furrow encircling the body. So far only recorded from one mud bottom site off the Swedish west coast. Biology and distribution otherwise unknown. ’	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE7BED56FCC0CFC7FB3DFDD0.taxon	materials_examined	Type species: Cephalomastax brevis Iwata, 1957, fixed by original designation. Diagnosis: Given by Iwata (1957: 5).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE7BED56FF14CC4EFBA8FEEA.taxon	description	(FIG. 2 B) Oxypolellinae gen. sp.: Hiebert, 2016: 318. Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org: act: 1 F 5 D 91 AE- 5 C 57 - 4 E 9 A-BE 20 - C 05 D 2 DA 554 B 4. Material examined: Four specimens, all collected by A. V. Chernyshev. Holotype, MIMB 42256, 23 May 2007, among dead corals, 2 – 4 m depth, Cù-Lao Ré Island (15 ° 23 ′ N, 109 ° 05 ′ E), Vietnam. Other material: two specimens, 19 May 2007, among dead corals, 5 – 7 m depth, Bach Long Vi Island (20 ° 09 ′ N, 107 ° 44 ′ E), Vietnam; one specimen, 22 May 2010, intertidal, among calcareous red algae, Van Phong Bay (12 ° 40 ′ N, 109 ° 20 ′ E), Vietnam. Sequence: From the holotype; KU 748595, 16 S (524 bp), determined by Hiebert (2016) as Oxypolellinae sp. TCH- 2017 isolate E 4 H 7. Etymology: The new specific name, a noun in the genitive case, honours Dr Terra C. Hiebert for her outstanding contribution to nemertean systematics. Description: Body soft, 2 – 4 cm long, 1 mm wide, dorsally yellow or lemon yellow, ventrally pale yellowish; head long, narrow, with two thin transverse furrows in front of mouth; eyes and caudal cirrus absent (Fig. 2 B). Rhynchopore ventral. Mouth small, pit-like. Rhynchocoel extending length of body. Two regions detected in proboscis of live specimens. Frontal organ present (from CSLSM observation; data not shown). Body wall with two dorsal nerves (from CSLSM observation; data not shown). Living worms with distinctive, permanent mucous tube. Distribution: Known only from Vietnam (present study). Remarks: Oxypolella hiebertae is the sixth member described in the genus (cf. Cantell, 2005). It resembles the most recently described species, Oxypolella banyulensis Cantell, 2005 from the Mediterranean, in having yellowish body colour. Oxypolella hiebertae differs from O. banyulensis in having cephalic furrows as well as in the body coloration; in O. hiebertae, the body is uniformly yellow, whereas in O. banyulensis, the anterior third of the body is white and the posterior two-thirds yellowish white.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE7BED54FC6CCCD4FD8FFEA4.taxon	description	(FIGS 2 C, 5 A – E)	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE7BED54FC6CCCD4FD8FFEA4.taxon	materials_examined	Material examined: Two non-type specimens. ICHUM 6267, serial transverse sections, 8 µm thick, Mallory, 13 slides, along with extracted total DNA; 19 February 2014, dredged between 35 ° 5 ′ 56 ″ N, 139 ° 34 ′ 10 ″ E, 249 m depth, and 35 ° 5 ′ 46 ″ N, 139 ° 34 ′ 04 ″ E, 309 m depth, at station 2 of the 2 nd JAMBIO Coastal Organism Joint Survey (Nakano et al., 2015), collected by H. Kajihara. ICHUM 6304, extracted total DNA and body fragment preserved in 99 % EtOH, collection data as for ICHUM 6267. Sequences: From ICHUM 6267: LC 178640, 28 S (2096 bp). From ICHUM 6304: LC 178651, H 3 (331 bp); LC 178689, 16 S (510 bp); LC 190961, COI (658 bp). Description: Two fragments of anterior body, each about 2.5 cm long and 2 mm wide. Background body colour pale peach, dorsally maroon; dorsal pigmentation not covering head (Figs 2 C, 5 A, B). Head not demarcated from body in normal state, but clear demarcation obvious when animal contracted (Fig. 5 A, B). Transverse cephalic furrow encircling head; secondary furrows present. Proboscis pore slightly behind tip of head (Fig. 5 B). Mouth behind cephalic furrow (Fig. 5 B). Anterior proboscis wall composed of glandular epithelium, outer longitudinal muscle layer, neural plexus, inner longitudinal muscle layer, and circular muscle endothelium (Fig. 5 C, D); longitudinal muscle fibres abutting neural plexus running diagonally, often penetrating nervous tissue (Fig. 5 D). Posterior proboscis wall composed of glandular epithelium, longitudinal muscle layer and endothelium (Fig. 5 C). Rhynchocoel wall composed of meshwork of interwoven longitudinal and circular (and maybe also diagonal) muscle fibres; circular component denser in inner portion (Fig. 5 E). Distribution: Known only from the type locality, Sagami Bay, Japan (Iwata, 1957; present study). Remarks: Because Cephalomastax brevis was originally described from a preserved specimen, the external features in the living state were unknown. However, Iwata’s (1 9 5 7: 6) description of the appearance of the preserved type specimen (before sectioning) matches perfectly our observations in that the ‘ body is pale chestnut in colour on the dorsal side except only the portion of the neck which is whitish; the ventral surface is white’. Other features such as the absence of eyes and the unique arrangement of the proboscis muscle layers in relation to the nerve plexus (outer longitudinal, nerve plexus, inner longitudinal, and inner circular muscle layers) add more credence to the species identification of our specimens.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE79ED54FF78CF00FDD3FBA6.taxon	materials_examined	Type species: Valencinura bahusiensis Bergendal, 1902, fixed by monotypy. Diagnosis: Senz (1996: 48) altered Bergendal’s (1902) original concept of the genus and gave the following modified diagnosis (our translation): Heteronemertea with unbranched proboscis; proboscis with inner longitudinal, middle circular and outer longitudinal muscle layers, with none or two muscle crosses; head without horizontal lateral cephalic slits; cerebral organs not penetrating into blood vessels; cutis without connective tissue layer; caudal cirrus present or absent; preseptal circular muscles with central muscle cone (= bundle of radiating muscle fibres); foregut vascular network present; foregut with no or few subepithelial glands; brain without outer neurilemma; no neurochord cells; body-wall inner circular muscle layer in foregut region present as muscle cylinder; rhynchocoel extending nearly length of body; rhynchocoel wall not interwoven with body-wall muscles.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE79ED55FEE2CA2BFB35FB0C.taxon	description	(FIGS 2 D, E, 4 D) Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org: act: E 998 BBEE-F 62 E- 4 D 2 A- 9 C 27 - DE 7 A 889056 B 4. Material examined: Holotype, ICHUM 6305, extracted total DNA (no morphological voucher remains); 19 February 2014, dredged at station 3 of the 2 nd JAMBIO Coastal Organism Joint Survey (Nakano etal., 2015), off Misaki, Sagami Bay, Kanagawa (between 35 ° 08 ′ 48 ″ N, 139 ° 34 ′ 41 ″ E, 87 m depth and 35 ° 08 ′ 38 ″ N, 139 ° 34 ′ 35 ″ E, 89 m depth), Japan, collected by H. Kajihara. Sequences: From the holotype: LC 178643, 28 S (2104 bp); LC 178692, 16 S (507 bp); LC 190964, COI (476 bp). Etymology: The new specific name is a noun in apposition, from the acronym for the Japanese Association for Marine Biology. Description: Anterior fragment, 2 cm long, 1 mm wide; anteriorly circular in cross-section, anterior 9 mm pure white; posteriorly flattened dorsoventrally, pinkish in colour (Fig. 2 D); rhynchocoel (or proboscis) yellowish (Fig. 2 E). Head pointed, not demarcated from body, but pair of transverse cephalic furrows present just anterior to mouth; no secondary furrows. Proboscis pore mid-ventral, opening between cephalic tip and mouth (Fig. 4 D). Distribution: Known only from the type locality, Sagami Bay, Japan (present study). Remarks: Our generic assignment of Valencinura jambio depends almost entirely on the phylogenetic closeness of this taxon to Vu. bahusiensis in our analyses (Fig. 1) and should be regarded as tentative and provisional, because the species could equally likely belong to Valencinia or Valencinina based on internal morphology, data that are lacking for this species. In Valencinia, Valencinina and Valencinura, the proboscis pore is located far posterior to the cephalic tip. At least some species in Valencinia and Valencinura are similar to one another in external appearance. They supposedly differ in the presence (in Valencinura) or absence (in Valencinia) of (1) the proboscis inner longitudinal muscles and (2) the body-wall inner circular muscle layer in the foregut region (e. g. Bürger, 1895 a; Bergendal, 1902; Senz, 1996). Valencinina and Valencinura are similar in having the proboscis anteroposteriorly differentiated into several regions. These two genera supposedly differ in the frontal organ, which is present in Valencinina but absent in Valencinura, and also in the outer longitudinal muscles in the posterior part of the proboscis, which are present in Valencinura but absent in Valencinina (Bergendal, 1902; Gibson, 1981 b). Additional morphological data will be necessary to ascertain the generic affiliation of Vu. jambio.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE79ED55FEE2CA2BFB35FB0C.taxon	description	Hereweelevate Valencinialongirostris var. rava Bürger, 1895 a to species rank as Valencinia rava; rava is an available species-group name in accordance with Article 45.6 of the Code (ICZN, 1999). Originally established as Valencinia longirostris var. rava from Naples (along with a redescription of Vi. longirostris, also from Naples), this species was later regarded as subspecies Joubinia longirostris rava (Bürger, 1904: 86). Recognizing two subspecies in the same locality, however, is not in accord with the modern concept of subspecies (Mayr, 1982; Monroe, 1982). As opposed to Vi. longirostris (posteriorly pink as in Vu. jambio), Vi. rava is posteriorly yellowish grey (and is thus different from Vu. jambio). The species Valencinia blanca Bürger, 1895 a has a uniformly white body and, thus, also differs from Vu. jambio. For the three potentially valid species Vi. blanca, Vi. longirostris, and Vi. rava, no earlier researchers (e. g. Quatrefages, 1846; Hubrecht, 1879; Bürger, 1895 a; Corrêa, 1956) described cephalic furrows, which are present in Vu. jambio. Indeed, Hubrecht (1879: 208) mentioned, as part of the generic diagnosis, that no cephalic furrows or fissures are present in Valencinia. Morphologically, Valencinia shares with Cephalomastax an unusual proboscis musculature in which the proboscis nerve lies between the two (inner and outer) longitudinal muscle layers, an arrangement unique in the phylum (Norenburg, 1993; Chernyshev, 2011 a). To the extent that this morphological similarity indicates a close phylogenetic relationship, Valencinia is presumably more closely related to Cephalomastax than to Valencinura, which supports our placement of Vu. jambio in Valencinura rather than in Valencinia, despite their close relationship in our phylogenetic tree (Fig. 1). Valencinura jambio differs from the two species in Valencinina in body colour: Valencinina albula Gibson, 1981 b is cream white overall, whereas Valencinina hubrechti Senz, 2001 is uniformly light brown. Aside from species in Valencinia, Valencinina and Valencinura, Vu. jambio differs in the following features from all other known heteronemerteans lacking horizontal lateral cephalic slits: in habitat (marine) from Apatronemertes, Planolineus and Siolineus (freshwater); in phylogenetic position (Fig. 1) from Baseodiscus, Cephalomastax, Oxypolella, Riserius, Sonnenemertes and Zygeupolia; in the nature of the cephalic furrows (paired and disjunct) from Oxypolia beaumontiana (continuous, encircling the head; Punnett, 1901); in body colour (anteriorly white; pink in the intestinal region) from Paralineopsis taki (blueish white anteriorly; foregut region pale yellow; intestinal region milky white; Iwata, 1993), Paramicrura borborophila (light beige-brown to pink-brown; Gibson & Sundberg, 1992), Parapolia aurantiaca (bright orange; Coe, 1895), Parapolia grytvikensis (pinkish brown; Wheeler, 1934), Poliopsis lacazei (dark pink; Joubin, 1890) and Pseudobaseodiscus nonsulcatus (light pink; Senz, 1993). Valencinura jambio further differs from Poliopsis in lacking the peculiar dorsal and ventral medial furrows on the head that are present in the latter (Joubin, 1890).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE78ED52FC8ACA85FD88FE8B.taxon	description	External features: Strand et al. (2010: 122) gave the following summary for the species: ‘ Length up to 6 cm, width up to 2 mm. An inconspicuous heteronemertean lacking eyes, furrows and slits. Body stout, circular in cross section, whitish with greyish tinge posteriorly. Anterior end tapering to a pointed nose, posterior end broad and blunt with a caudal cirrus. Mouth visible as an orange dot ventrally. ’ Distribution: Swedish west coast, outside Lysekil and in the Kosterfjord (Bergendal, 1902; Strand et al., 2010; Strand & Sundberg, 2011). Remarks: According to Strand et al. (2010), the specimen sequenced was collected in 2007 from a depth of 30 m on a rough-sandy seabed with a mixture of algal residue and other organic material.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE7FED52FF1DCF0EFB19FEE9.taxon	diagnosis	Diagnosis: Given by Gibson (1994: 114). An additional feature is the proboscis musculature consisting of inner circular, middle diagonal, and outer longitudinal layers (Magarlamov & Chernyshev, 2011). Remarks: The publication year of the generic name Polia Delle Chiaje is 1822 rather than 1825 (e. g. Gibson, 1995: 475) or 1827 (e. g. Neave, 1940: 844) as previously regarded, in accordance with Article 12.2.7 of the Code (ICZN, 1999); the type species has not been fixed. The name Polia Delle Chiaje was first used for the following six nominal species, originally appearing as captions for plates supposedly published in 1822, while the written descriptions for these species were supplied in Volume 2 (issued in 1825 or 1827) (see Remarks for Baseodiscus delineatus below) or Volume 3 (issued in 1828): Polia caerulescens Delle Chiaje, 1822 (pl. XLIII, fig. 9) (description in Volume 3 as ‘ P. cilestra ’: 172 – 173); Polia delineata Delle Chiaje, 1822 (pl. XXVIII, fig. 4) (description in Volume 2 as ‘ P. lineata ’ on p. 409 and as ‘ P. delineata ’ on pp. 427 – 428; the specific name also appears on p. 444 in the explanations for plates); Polia geniculata Delle Chiaje, 1822 (pl. XLIII, fig. 10; LXXVIII, figs 5, 6) (description in Volume 3: 177); Polia oculata Delle Chiaje, 1822 (LXXVIII, fig. 8) (description in Volume 3: 172, 177; the name also occurs on p. 181 in the explanations for plates); Polia punctata Delle Chiaje, 1822 (pl. LXVIII, figs 7, 11) (description in Volume 3, as ‘ P. punteggiata ’ on p. 172 and ‘ P. punctata ’ on p. 177; the name also occurs on p. 181 in the explanations for plates); and Polia siphunculus Delle Chiaje, 1822 (pl. XXVIII, figs 1 – 3) (description in Volume 2, as ‘ P. sipuncolo ’ on pp. 406 – 408 and ‘ P. sipunculus ’ on p. 427). However, these complications do not overturn precedence of the senior homonym Polia Ochsenheimer, 1816 (Lepidoptera: Noctulidae) over Polia Delle Chiaje, 1822.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE7FED50FC90CFE6FE11FD91.taxon	description	(FIGS 2 F, 6 A – E)	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE7FED50FC90CFE6FE11FD91.taxon	materials_examined	Material examined: ICHUM 6266, transverse sections, 5 µm thick, Mallory, 43 slides, along with unsectioned body fragment in 99 % EtOH; March 2012, under stone, subtidal, 10 m depth, SCUBA diving, mouth of Koajiro Bay (35 ° 09 ′ 51 ″ N, 139 ° 36 ′ 53 ″ E), K a n a g awa, Ja p a n, c o l l e c t e d b y H. K o h t s u k a. ICHUM 6306, body fragment in 99 % EtOH, 4 June 2012, among laminarian holdfasts, rocky intertidal, Oshoro Bay (43 ° 12 ′ 43 ″ N, 140 ° 51 ′ 13 ″ E), Hokkaido, Japan, collected by H. Kajihara. ICHUM 6307, body fragment in 99 % EtOH, collection data same as for ICHUM 6266. ICHUM 6309, body fragment in 99 % EtOH, juvenile, 18 April 2014, among roots of the seagrass Phyllospadix iwatensis Makino, Oshoro Bay, Hokkaido, Japan, collected by H. Kajihara. ICHUM 6308, anterior body fragment (~ 70 cm long) in 99 % EtOH, 24 August 2016, among sunken scallop shells used for sea cucumber mariculture, 5 m depth, 300 m offshore, Date (42 ° 27 ′ 30 ″ N, 140 ° 52 ′ 03 ″ E), Hokkaido, Japan, collected by H. Kajihara. Sequences: From ICHUM 6266: LC 178612, 28 S (2120 bp); LC 178645, H 3 (331 bp); LC 178654, 16 S (507 bp). From ICHUM 6306: LC 178583, 18 S (1795 bp); LC 178610, 28 S (2094 bp); LC 178652, 16 S (506 bp). From ICHUM 6307: LC 178611, 28 S (2121 bp); LC 178644, H 3 (331 bp); LC 178653, 16 S (507 bp); LC 190937, COI (658 bp). From ICHUM 6309: LC 178584, 18 S (1793 bp); LC 178613, 28 S (2120 bp); LC 178646, H 3 (331 bp); LC 178655 16 S (507 bp); LC 190938, COI (658 bp). Description: Background body colour wheat to light orange, mottled with black to dark brown patches of varying size and shape (Figs 2 F, 6 A, B); body markings uniformly distributed both dorsally and ventrally in large specimens, but only dorsally in juveniles (Fig. 6 C, D). Head demarcated from body with transverse cephalic furrow; secondary furrows present. Mouth mid-ventral, behind cephalic furrow (Fig. 6 A). Eyes numerous, arranged along cephalic margin on each side, also on dorsal surface of head just anterior to cephalic furrow (sparse near midline). No caudal cirrus. Proboscis pore terminal. Rhynchocoel wall consisting of inner longitudinal and outer circular muscle layers. Proboscis wall composed of glandular epithelium, neural plexus, outer longitudinal muscle layer, and inner circular muscle layer (Fig. 6 E). Distribution: So far confirmed only from eastern Japan: Misaki, Honshu (type locality; Takakura, 1898; present study); Date, Hokkaido (present study); and Oshoro, Hokkaido (present study). Remarks: Takakura (1898) recorded an unidentified form as Eupolia sp., stating that it resembled Eupolia antillensis Bürger, 1895 a. Gibson (1995) mistakenly thought that Takakura (1898) had established a new taxon with the specific name antillensis, and introduced the new name Baseodiscus takakurai for Takakura’s (1898) Eupolia sp.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE7DED50FF18CC17FA73FE2E.taxon	description	(FIG. 2 G) Baseodiscinae sp. 21 DS: Chernyhsev & Polyakova, 2018: 125, 128, 130, table 1, fig. 1 F, fig. 4 B. Baseodiscinae sp. 7 DS: Cheryshev & Polyakova, 2018: 125, table 1. Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. o r g: a c t: C 8 9 2 A 8 8 C - D E B F - 4 4 A 5 - A D 1 C - 0 DE 7 D 9823 B 69. Material examined: Two specimens, collected by A. V. Chernyshev. Holotype, MIMB 42257, 22 July 2015, S / V Akademik M. A. Lavrentyev, station 7 - 1, Sea of Okhotsk (46 ° 57.0 ′ N, 151 ° 05.0 ′ E), 3300 m depth, mud. Paratype, MIMB 42258, 23 July 2015, S / V Akademik M. A. Lavrentyev, station 7 - 11, Sea of Okhotsk (46 ° 57.0 ′ N, 151 ° 00.4 ′ E), 3306 m depth, mud. Sequences: Determined by Chernyshev & Polyakova (2018). From the holotype (as Baseodiscinae sp. 21 DS): MF 512047, 16 S (499 bp); MF 512072, 18 S (1760 bp); MF 512098, 28 S (359 bp); MF 512140, H 3 (331 bp). From the paratype (as Baseodiscinae sp. 7 DS): MF 512045, 16 S (499 bp); MF 512070, 18 S (1770 bp); MF 512096, 28 S (1050 bp); MF 512138, H 3 (331 bp). Etymology: The new specific name is the Latin adjective profundus meaning ‘ deep’. Description: Body 25 – 27 mm long, 1.0 – 1.2 mm wide, cylindrical in foregut region and slightly flattened in region of intestine; head dark rose, body pale rose, yellowish gonads visible through integument (Fig. 2 G); thin transverse furrows present; secondary furrows not confirmed; eyes absent; mouth small, pit-like. Diagonal muscle layer absent in proboscis (Chernyshev & Polyakova, 2018). Distribution: Known only from the Sea of Okhotsk (Chernyshev & Polyakova, 2018). Remarks: This new species differs from other species in the genus in having a relatively small, narrow body lacking any specific colour patterning. Baseodiscus profundus may be unique within the genus in lacking the proboscis inner diagonal musculature, which has been confirmed in all the other congeners studied so far (Magarlamov & Chernyshev, 2011; Chernyshev, 2015).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE7DED51FC74CFADFACCFB85.taxon	description	(FIGS 2 H, I, 7 A) Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. o r g: a c t: 7 5 D 6 F E 5 2 - E A 1 1 - 4 5 5 1 - 8 E 6 F - FDAB 23 BDFD 06. Material examined: Holotype, ICHUM 6310, entire body and extracted total DNA preserved in 99 % EtOH; 26 September 2011, among dead coral, ~ 10 m depth, SCUBA, Amitori Bay (35 ° 09 ′ 51 ″ N, 139 ° 36 ′ 53 ″ E), Iriomote Island, Japan, collected by T. Naruse. Sequences: From the holotype: LC 178598, 18 S (1801 bp); LC 178628, 28 S (2110 bp); LC 178675, 16 S (504 bp); LC 190951, COI (658 bp). Etymology: The new specific name is a noun in the genitive case, after Dr Tohru Naruse (University of the Ryukyus), a Japanese decapod crustacean researcher, who found the type material. Description: Background body colour pale greyish, densely mottled with chocolate brown pigment except laterally (Figs 2 H, I, 7 A). Mouth large (Fig. 2 I), opening twice as long as head (i. e. from tip of head to cephalic furrow). Distribution: So far known only from the type locality, Iriomote Island, at the southern margin of the East China Sea (present study). Remarks: Baseodiscus narusei is most closely related to B. paracelensis; both species have a pale beige background with dark-brown mottling, but B. narusei differs from the latter in having the lateral margins of the body white. In addition, the mottling is fainter in B. narusei than in B. paracelensis, where the contrast between the mottling and the background colour is sharper. The two species differ at two of the 220 amino-acid positions translated from the 658 - bp COI sequences: position 121, valine in B. narusei, isoleucine in B. paracelensis; position 140, valine in B. narusei, alanine in B. paracelensis. At least one of the food items of Baseodiscus narusei seems to be the big blue octopus Octopus cyanea Gray, 1849 (see Potential food items below). Sequences: From the holotype: LC 178600, 18 S (1773 bp); LC 178649, H 3 (331 bp); LC 178678, 16 S (504 bp); LC 190952, COI (658 bp). Etymology: The new specific name is an adjective, referring to the type locality. Description: Body about 1 m long; background body colour pale peach yellow, mottled with amorphous, reddish brown markings, mostly dots and longitudinal lines that often merge with one another (Figs 2 J, 7 B). Eyes numerous. Mouth long, slit-like. Cephalic furrows well developed. Distribution: So far known only from the type locality, the South China Sea (present study). Remarks: With the entire body having a pale beige background mottled with brownish, B. paracelensis might previously have been confused with B. delineatus (e. g. Bürger, 1904; Gibson, 1979); however, they can easily be distinguished in that the mottles are anteroposteriorly fused to form continuous stripes, especially in the posterior part of the body, and evenly separated in B. delineatus, whereas the stripes are more often broken and irregularly separated in B. paracelensis. Baseodiscus paracelensis looks similar to B. takakurai, but differs from the latter in the colour of the mottles, which are more paler than those in B. takakurai. In Figure 1, it is the sister-species to B. narusei.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE7CED51FF1DC871FDA9F8DB.taxon	description	(FIGS 2 J, 7 B) Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org: act: 33 BCC 3 BA- 792 C- 443 E-A 579 - 27 E 06 A 9 E 8 A 5 B. Material examined: Holotype, MIMB 33132 (morphological voucher), ICHUM 6311 (DNA voucher), 26 January 2005, subtidal, among dead coral, 69 m depth, off the Paracel Islands (16 ° 07 ′ 36 ″ N, 114 ° 47 ′ 36 ″ E), South China Sea, collected by A. V. Chernyshev during an expedition on S / V Academic Oparin.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE7CED5EFC4FCA14FD60FC67.taxon	description	(FIGS 2 K, 6 F) Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org: act: 28 FE 54 EB-D 2 A 3 - 4 D 1 F- 9 A 60 - 302696 A 12338. Material examined: Two specimens; detailed depth information lacking for both, but probably <20 m depth. Holotype, NMNS-Ne 1 (DNA voucher ICHUM 6342), 27 June 2014, subtidal, SCUBA diving, Nishijima-Oiwa (27 ° 07 ′ 06 ″ N, 142 ° 10 ′ 19 ″ E), Ogasawara Islands, Japan, collected by H. Komatsu. Paratype, ICHUM 6312, 27 May 2001, subtidal, SCUBA diving, among coral rubble, Kakeroma-jima (c. 28 ° 7 ′ 29 ″ N, 129 ° 14 ′ 41 ″ E), Kagoshima, Japan, collected by H. Kajihara. Sequences: From the holotype: LC 178597, 18 S (1775 bp); LC 178627, 28 S (2107 bp); LC 178648, H 3 (331 bp); LC 178673, 16 S (504 bp). From the paratype: LC 178596, 18 S (1798 bp); LC 178626, 28 S (2123 bp); LC 178672, 16 S (479 bp). Etymology: The new specific name is a noun in the genitive case, after Dr Hironori Komatsu (National Museum of Nature and Science, Japan), a Japanese carcinologist, who collected the holotype specimen. Description: Background body colour beige, uniformly mottled with brown to dark-olive dots and lines on dorsal, ventral and lateral surfaces of body (Figs 2 K, 6 F). Eyes and cephalic furrows (with secondary furrows) present, as in congeners. In life, holotype 120 cm long, 8 mm wide; paratype, 16 cm long, 2.5 mm wide. Distribution: So far known from the Ogasawara Islands (type locality) and the island of Kakeromajima in Japanese waters, but probably more widely distributed in warm waters in the western Pacific. Remarks: The mottling pattern in Baseodiscus komatsui resembles that in B. takakurai, but the two species differ in body colour: the mottling is much paler in the former than in the latter, where it is dark brown or black; the background colour is light beige in B. komatsui, yellowish in B. takakurai. The mottling tends to be blurred in the posterior part of the body in B. komatsui. These two species differ at six of the 220 amino-acid positions translated from the 658 - bp COI sequences: positions 118 and 122, alanine in B. komatsui, serine in B. takakurai; 126, glycine in B. komatsui, alanine in B. takakurai; 154, isoleucine in B. komatsui, valine in B. takakurai; 159, arginine in B. komatsui, leucine in B. takakurai; 190, glycine in B. komatsui, alanine in B. takakurai.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE73ED5FFC74CC9FFE7AFEEA.taxon	description	(FIG. 2 M)	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE73ED5FFC74CC9FFE7AFEEA.taxon	materials_examined	Material examined: Photographs of type material, taken by G. Giribet. Holotype, MCZ IZ- 135324 (MCZ DNA 105588), 30 March 2006, Isla Solarte (09 ° 18 ′ 36.6 ″ N, 82 ° 13 ′ 01 ″ W), Bocas del Toro Archipelago, Panama, collected by G. Giribet. Sequences: From the holotype: JF 293046, 18 S (1772 bp); HQ 856866, 28 S (1863 bp); JF 277749, H 3 (326 bp); JF 277569, 16 S (449 bp); HQ 848589, COI (657 bp). Determined by Andrade et al. (2012) and deposited in GenBank as Baseodiscus sp. 2 SA- 2011. Etymology: The specific name is dedicated to the collector of the type material, Prof. Gonzalo Giribet (Harvard University), for his remarkable contribution to the systematics of not only nemerteans but also Metazoa in general. Description: Body uniformly pale brown in colour, without any distinctive colour pattern (Fig. 2 M). Distribution: So far detected only on the Caribbean coast of Panama (present study). Remarks: In our ML tree (Fig. 1), Baseodiscus giribeti was most closely related to B. unicolor. They differed by 5.6 % in uncorrected P - distance for 16 S (KF 935452, KF 935459, JF 277569 vs. KF 935451, EF 124865) and 9.0 % for COI (HQ 848589 vs. KF 935505) [KF 935452 and JF 277569 are from the same specimen, IZ- 135324 (MCZ DNA 105588)].	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE73ED5EFF48CA64FA84FD14.taxon	description	(FIG. 2 L)	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE73ED5EFF48CA64FA84FD14.taxon	description	External features: Body brown to reddish brown in colour, without any distinctive pattern (Fig. 2 L) (cf. Schwartz, 2009: 69). Distribution: Spanish Water, Curaçao (type locality; S t i a s n y - W i j n h o f f, 1 9 2 5); C a t C a y, B e l i z e (Schwartz, 2009); Manawar Cay, Bocas del Toro Archipelago, Panama (Kvist et al., 2014). Remarks: We regard the two specimens analysed to represent B. unicolor. Stiasny-Wijnhoff (1925: 103) described the body colour as ‘ a dark reddish brown without any markings’ after ‘ preservation with sublimate and alcool [sic] ’. There appear to be two distinct species along the Caribbean coasts of Central and South America, both having brownish body colour without any distinctive patterning. They seem to differ in the shade / depth of the brown colour; the dark-brown form should be referred to by the name B. unicolor in reference to Stiasny-Wijnhoff ’ s (1925) original description. For the pale-coloured form, we establish B. giribeti; see Remarks for that species (following).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE72ED5FFF27CFD8FB61FAF5.taxon	description	(FIG. 2 N)	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE72ED5FFF27CFD8FB61FAF5.taxon	materials_examined	Material examined: One specimen (DNA voucher ICHUM 6313), 18 May 2010, among dead corals, 6 – 9 m depth, Cù Lao Thu Island (10 ° 32 ′ N, 108 ° 55 ′ E), Vietnam, collected by A. V. Chernyshev. Sequences: From ICHUM 6313: LC 178599, 18 S (1804 bp); LC 178629, 28 S (2086 bp); LC 178676, 16 S (508 bp). Description: In life, the specimen examined (Fig. 2 N) was ‘ about 1 m long, ground colour pale yellowish with numerous reddish brown longitudinal stripes situated irregularly on both dorsal and ventral surfaces; about 80 – 90 eyes on each side of head; transverse cephalic furrows present, each with 50 – 60 secondary grooves’ (Chernyshev, 2016: 289). The mouth is small and rounded, not slit-like (Chernyshev, 2016, fig. 4 A). Remarks: In the preserved state, Staub’s (1900) material of Eupolia amboinensis from Ambon, Indonesia, reached 30 cm in body length and 5 mm in width, with a dark background body colour having light-brown longitudinal stripes, which are interrupted, branched and reticulate. Eupolia reticulata, also from Ambon, reached up to 27 cm long and 6 mm wide (Staub, 1900), and had nearly the same external appearance as Eupolia amboinensis, and thus can be regarded as conspecific; indeed, Gibson (1979) synonymized these two nominal species under Baseodiscus delineatus, although with some reservation. Our specimen from the South China Sea has a bright yellowish background colour, entirely overlain with longitudinal, intermittent, reddish brown stripes, which are more closely set relative to one another than in Baseodiscus delineatus (Fig. 3 C), making it difficult to tell which (bright yellow or reddish brown) is the background colour, especially in the posterior part of the body. The brown stripes appear to be narrower than those in Baseodiscus cf. curtus (Fig. 3 F). Our specimen is thus compatible with Staub’s (1900) descriptions and illustrations of Eupolia amboinensis and E. reticulata. The geographical distance of ~ 2600 km between the South China Sea and Banda Sea localities leaves room for doubt as to the identification of our material as Baseodiscus amboinensis. Barcode sequences from topotypes will be necessary to resolve this uncertainty. Due to insufficient knowledge of the genetic diversity among species of Baseodiscus in the tropical Indo-West Pacific, our material was tentatively identified first as Baseodiscus delineatus (Chernyshev, 2011 b) and then as Baseodiscus jonasii (Chernyshev, 2015, 2016). The uncorrected p - distance for 16 S sequences between our material (LC 178676) and Baseodiscus jonasii (AY 955231) was 4.3 %, which is greater than some values known between congeneric lineid heteronemertean species that were confirmed to be biologically different by cross-fertilization experiments, e. g. 4.0 % (Hiebert & Maslakova, 2015) between Maculaura alaskensis (Coe, 1901 a) and Maculaura oregonensis Hiebert & Maslakova, 2015, and 2.8 % (Ikenaga et al., 2021) between Kulikovia alborostrata (Takakura, 1898) and Kulikovia fulva (Iwata, 1954). Our specimen differs from B. jonasii in that the background and stripe colours are reversed between the two species: in B. jonasii, the background colour is reddish brown and the stripes are yellowish beige (Strand et al., 2005), as in Borlasia striata Quoy & Gaimard, 1833 from Guam. The latter has a red background colour with pale reddish stripes (Quoy & Gaimard, 1833: 286, pl. 24, figs 3, 4), and thus may be a senior synonym of B. jonasii.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE72ED5CFC9CCBFAFD9CFEAA.taxon	distribution	Distribution: So far known only from the Solomon Islands (Strand et al., 2005). Remarks: According to Strand et al. (2005), sequence AY 955230 (16 S, 471 bp) came from the holotype. Although we did not include this sequence in our analysis, it is identical with AY 955231 except for one nucleotide insertion. Borlasia striata Quoy & Gaimard, 1833 from Guam may be a senior synonym of Baseodiscus jonasii (see Remarks for B. cf. amboinensis above).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE71ED5CFF50CF36FAD4FCBC.taxon	description	(FIG. 2 O)	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE71ED5CFF50CF36FAD4FCBC.taxon	materials_examined	Material examined: Four specimens; extracted total DNA and remaining body preserved in 99 % EtOH. ICHUM 6314, 6315, 22 May 2008, rocky intertidal, Iheyajima (27 ° 02 ′ 09 ″ N, 127 ° 58 ′ 02 ″ E), Okinawa, Japan, collected by K. Kakui; ICHUM 6316, 6317, 25 May 2001, Tanegashima, Kagoshima (30 ° 49 ′ 28 ″ N, 131 ° 02 ′ 18 ″ E), Japan, SCUBA, ~ 5 m depth, collected by H. Kajihara. Sequences: From ICHUM 6314: LC 178593, 18 S (1793 bp); LC 178623, 28 S (2107 bp); LC 178668, 16 S (510 bp); LC 190946, COI (658 bp). From ICHUM 6315: LC 178594, 18 S (1794 bp); LC 178624, 28 S (1095 bp); LC 178669, 16 S (512 bp); LC 190947, COI (658 bp). From ICHUM 6316: LC 178595, 18 S (1794 bp); LC 178625, 28 S (2007 bp); LC 178670, 16 S (510 bp); LC 190948, COI (658 bp). From ICHUM 6317: LC 178671, 16 S (510 bp). Description: Body white, with cephalic patch and middorsal stripe (Fig. 2 O), anterior end of latter widening laterally and reaching ventral side. Distribution: Widely distributed in the Indo-Pacific from the Red Sea to Easter Island (summarized in Kajihara & Hookabe, 2019, fig. 1). Remarks: Baseodiscus hemprichii is one of the few nemertean species that can be reliably identified by only the external appearance, even after preservation. It can reproduce asexually by fragmentation followed by anterior regeneration (Kajihara & Hookabe, 2019). Kajihara & Kato (2008) listed the diagnostic external features in this species, which include ‘ whitish body, with head demarcated from the body by a transverse furrow encircling the neck; minute secondary furrows may be present in life, running anteriorly from the main transverse furrow, difficult to confirm in preserved state; numerous ocelli arranged along the margin of the head; a single dark-coloured (purplish, dark brown or black) cephalic patch situated at the posterior portion of the dorsal surface of the head; and a dorsal and ventral stripe of the same coloration as the cephalic patch; the anterior end of the dorsal stripe laterally widened to form a T-shaped collar’. Kazmi & Gibson (1994) reported an individual from Karachi, Pakistan, in which the mid-dorsal stripe was discontinuous and regularly interrupted, as in B. edmondsoni Coe, 1934 from Hawaii (Coe, 1934, 1947). Given the sister-taxon relationship (Fig. 1) between B. hemprichii and a clade containing two ‘ banded’ species (B. mexicanus and B. zebra), B. hemprichii sensu Kazmi & Gibson (1994) may possibly represent a hybrid between B. hemprichii s. s. and one of these banded forms, or yet one more new species.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE71ED5DFC42CD45FD5DFCBF.taxon	description	(FIG. 2 P)	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE71ED5DFC42CD45FD5DFCBF.taxon	materials_examined	Material examined: Holotype, RUMF-ZN- 00001 (DNA voucher ICHUM 6317), 31 March 2012, 3 – 4 m depth, Cape Manza (26 ° 30 ′ 16 ″ N, 127 ° 50 ′ 39 ″ E), On’na-son, west coast of Okinawa-jima, Japan, SCUBA, collected by D. Uyeno. Sequences: From ICHUM 6317: LC 178607, 18 S (1795 bp); LC 178639, 28 S (2086 bp); LC 178688, 16 S (505 bp); LC 190960, COI (658 bp). Etymology: The new specific name is a noun in the nominative case, referring to the colour pattern of the species. Description: Head white, with indigo dorsal and ventral cephalic patches; with transverse cephalic furrow encircling neck; numerous secondary furrows present; numerous, small, black eyes distributed laterally along sides of head. Body white, with numerous bands of same colour as cephalic patches (Fig. 2 P). Distribution: Although molecularly confirmed only from the type locality, Okinawa (Japan), B. zebra is probably distributed widely in the western Pacific. Remarks: Sequences LC 190960 (COI) and LC 178688 (16 S) from the holotype differ by 12.6 % and 6.8 % in uncorrected p - distance from KF 935503 (COI) and KF 935449 (16 S), respectively, both from MCZ IZ- 135321 collected in Baja California, Mexico and identified as B. mexicanus by G. Giribet (Kvist et al., 2014; MCZbase, www. mcz. harvard. edu). Kajihara et al. (2012) argued a possible amphi-Pacific distribution for B. mexicanus, but the western-Pacific population (possibly extending from Japan via Palau to Australia; Colin & Arneson, 1995; Chernyshev & Volvenko, 2008) is here regarded as a distinct species. Because the type locality of B. mexicanus is Mazatlán, Mexico (Bürger, 1893), the name mexicanus should be applied to the eastern-Pacific population, in which Coe (1940: 261) noted the colour to be variably brownish green, maroon, deep red, mahogany or brownish violet. The body colour appears to be generally reddish in B. mexicanus, whereas in B. zebra it is bluish.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE70ED5AFF0DCD3DFD0DF99F.taxon	materials_examined	Material examined: None. Sequences: KF 935281, 18 S (1768 bp); KF 935337, 28 S (2088 bp); KF 935393, H 3 (227 bp); KF 935449, 16 S (503 bp); KF 935503, COI (658 bp). Determined by Kvist et al. (2014) and deposited in GenBank as derived from isolate SK 66; the voucher specimen has been deposited at the MCZ under catalogue number IZ- 135321, preserved in 95 % ethanol, collected on 30 December 2001, La Paz, Faro de Puerto Balandra, Baja California Sur, Mexico, identified by G. Giribet. External features: Body usually 20 – 80 cm long, but occasionally up to 2 – 4 m; with distinctive coloration pattern consisting of brownish green, maroon, deep red, mahogany or brownish violet background with numerous white rings encircling body at irregular intervals (Coe, 1940). Distribution: West coast of Mexico (Bürger, 1893; Joubin, 1905; Coe, 1940; Hochberg & Lunianski 1998), Panama (Coe, 1905, 1940, 1944), Colombia (Hochberg & Lunianski, 1998), Galapagos Islands (Coe, 1944; Hochberg & Lunianski, 1998) and Chile (Friedrich, 1970). Remarks: Two partial 16 S sequences deposited in GenBank, EF 124863 (483 bp; La Paz, Mexico) and EF 124918 (529 bp), both collected and identified by M. L. Schwartz as B. mexicanus, are identical with our sequence (KF 935449).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE70ED5AFF0DCD3DFD0DF99F.taxon	materials_examined	Material examined: Three specimens; extracted total DNA and remaining body preserved in 99 % EtOH. ICHUM 6319, 4.5 m long, 1.2 cm wide, 24 November 2014, Irabu-jima (24 ° 48 ′ 40 ″ N, 125 ° 10 ′ 54 ″ E), collected by R. Yoshida. ICHUM 6320, 1.2 m long, 1 cm wide, 21 May 2005, Bisezaki (26 ° 42 ′ 35 ″ N, 127 ° 52 ′ 47 ″ E), Okinawa-jima, coral reef, ~ 1 m depth, collected by H. Kajihara. ICHUM 6321, 20 July 2013, Okinawa, collected by H. Yamasaki. Sequences: From ICHUM 6319: LC 178602, 18 S (1789 bp); LC 178650, H 3 (331 bp); LC 178683, 16 S (518 bp); LC 190955, COI (658 bp). From ICHUM 6320: LC 178633, 28 S (1111 bp); LC 178681, 16 S (517 bp). From ICHUM 6321: LC 178634, 28 S (1410 bp); LC 178682, 16 S (517 bp). Description: Body greyish white, with five (three dorsally, two ventrally) dark-brown longitudinal stripes (Fig. 2 Q). Distribution: Indo-West Pacific. India (Venkataraman et al., 2012), Torres Straits (Punnett, 1900 c), Gulf of Thailand (Putchakarn, 2009), Singapore (Bürger, 1895 b; Punnett, 1900 b), Indonesia (Bürger, 1893; Staub, 1900), Philippines (Stimpson, 1857), Japan (Stimpson, 1857; Kajihara, 2017; present study), New Guinea (Quoy & Gaimard, 1833), Australia (Bürger, 1895 b; Gibson, 1979), Solomon Islands (Gibson & Sundberg, 2002), New Caledonia (Punnett, 1900 a). Remarks: The most common type has three stripes dorsally and two ventrally, a feature shared by the nominal taxa Borlasia quinquelineata, Eupolia trilineata and Taeniosoma aequale. However, there is almost continuous variation between the condition in the common type and that seen in other nominal taxa; for example, the dorsal stripes on both sides can be doubled (as in Taeinosoma aequale) or tripled (as in Eupolia novemlineata), or anteriorly tripled and posteriorly doubled (as in Taeniosoma septemlineatum). Gibson (1979) tentatively listed these nominal taxa as potentially conspecific with Baseodiscus quinquelineatus and they are indeed likely to be so. Gibson (1979: 154; 1995: 368) listed Eupolia lineolata (Bürger, 1895 a: 604; Bürger, 1895 b: 28 – 29, pl. 2, figs 4, 8) from Tuamotus (originally given as ‘ Paumatu-Ins. ’ in Bürger, 1895 a, b) and Upolu (Samoa) as possibly synonymous with Baseodiscus quinquelineatus. However, Baseodiscus lineolatus is probably a different species, because its stripes are discontinuous and more numerous than in B. quinquelineatus. The individual shown in an in situ, underwater photo in Colin & Arneson (1995: 150, fig. 684) from Mactan Island (Cebu, Philippines) and identified as ‘ Baseodiscus delineatus ’, and another individual in Johnson & Johnson (2019 a) from the Marshall Islands identified as ‘ Baseodiscus cf. delineatus ’, show stripes like those illustrated by Bürger (1895 b) for B. lineolatus. Baseodiscus quinquelineatus seems to feed on terebellid polychaetes (see Potential food items below).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE77ED5BFF42C818FDE6FE8B.taxon	description	(FIGS 3 A, 7 C)	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE77ED5BFF42C818FDE6FE8B.taxon	materials_examined	Material examined: Two specimens, both collected by A. V. Chernyshev; one specimen (DNA voucher ICHUM 6322) collected 19 May 2010, among dead corals, 6 – 8 m depth, Cù Lao Thu Island (10 ° 31 ′ N, 108 ° 55 ′ E), Vietnam; the other (DNA voucher ICHUM 6323) collected 26 May 2010, among dead corals, 5 – 10 m depth, Cù Lao Chàm Island (15 ° 53 ′ N, 108 ° 31 ′ E), Vietnam. Sequences: From ICHUM 6322: LC 178585, 18 S (1812 bp); LC 178614, 28 S (1114 bp); LC 178656, 16 S (516 bp). From ICHUM 6323: LC 178586, 18 S (1808 bp); LC 178657, 16 S (516 bp). Description: Body about 20 cm long, pale yellowish, with numerous, brown, short, broken longitudinal stripes covering entire dorsal side (Fig. 3 A); ventral surface of head without brown pigmentation; sparse brown patches present ventrally behind mouth (Fig. 7 C). Head with approximately 60 eyes in each half. Distribution: Baseodiscus marmoratus s. s. (see below) is known only from Ambon, Indonesia (Bürger, 1890). Our material from Vietnam is of uncertain affinity to that species. Remarks: We identified our specimens from Vietnam with uncertainty as Baseodiscus aff. marmoratus. Bürger (1890) noted that his material for Eupolia marmorata from Ambon ranged from 3 – 4 mm wide × 6 – 8 cm long to 8 mm wide × 20 cm long; the mouth is small and pore-like; the background body colour is whitish; dorsally there are fine, anastomosing, dark-brown longitudinal lines of longitudinal striation, forming a dense network; ventrally, the edges of the striae are farther apart, leaving the background body colour more visible. Our specimens from Vietnam have the stripes more discontinuous and sparser than those in E. marmorata and thus may represent a different species. Reliable identification will require barcode sequences from topotypes. Bürger (1904: 82) synonymized Eupolia marmorata with B. curtus, and Gibson (1995: 368) later synonymized it with Baseodiscus delineatus. Here we combine the specific name marmorata with Baseodiscus, as B. marmoratus. Our material agrees with Bürger’s (1890) description and illustration for E. marmorata in that the background body colour is pale yellowish, covered with brownish, broken stripes. This colour pattern itself is similar to that of B. delineatus, but B. marmoratus differs from B. delineatus in having the stripes darker and more closely set to one another, especially in the posterior part of the body. Baseodiscus marmoratus cannot be confused with B. curtus because the ventral surface of the body in the latter is devoid of stripes or markings. In terms of uncorrected p - distance for 524 - bp 16 S sequences in our dataset, B. aff. marmoratus differed by 14.9 – 15.2 % from B. cf. curtus and by 11.9 % from B. delineatus. Baseodiscus aff. marmoratus seems to feed on terebellid polychaetes (see Potential food items below).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE76ED5BFF56CF09FB4EFEC8.taxon	description	(FIG. 3 B)	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE76ED5BFF56CF09FB4EFEC8.taxon	description	Micronesia).? Baseodiscus maculosus: Bürger, 1904: 84; Gibson, 1995: 304, 368.? Baseodiscus delineatus var. curtus: Coe, 1940: 261 (in part).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE76ED5BFF56CF09FB4EFEC8.taxon	materials_examined	Material examined: One specimen (DNA voucher ICHUM 6324), 23 May 2007, among dead corals, 2 – 4 m depth, Cù Lao Re Island (15 ° 23 ′ N, 109 ° 05 ′ E), Vietnam, collected by A. V. Chernyshev. Sequences: From ICHUM 6324: LC 178674, 16 S (482 bp); LC 190950, COI (658 bp). Description: Body 3 – 4 cm long. Background body colour pale yellow, mottled over entirety with numerous minute brown dots (Fig. 3 B); dots sparser ventrally. Head with numerous eyes and two transverse cephalic furrows, each with secondary grooves. Distribution: Baseodiscus maculosus s. s. is known only from the original description from Pohnpei (formerly, Ponape), Caroline Islands, Micronesia (Bürger, 1895 b); our specimen identified as Baseodiscus aff. maculosus was from Vietnam. Remarks: Our specimen was collected from Cù Lao Re Island, Vietnam, 5400 km distant from the type locality. We tentatively identify it as B. aff. maculosus on the basis of the similarity in body markings, consisting of minute, dark-coloured dots spread all over the pale-coloured body. However, the dots in the Vietnam specimen are denser than indicated in the original illustration (Bürger, 1895 b, pl. 2, fig. 2) and its body (3 – 4 cm) was much shorter than Bürger (1895 a, b) indicated for the type specimen (c. 50 cm long, 6 mm wide). The specimen from Vietnam may thus represent a different species. Johnson & Johnson (2019 b) photographed an individual from the Marshal Islands (labelled ‘ Emplectonema? sp. 1 ’) that was more than 1 m long, with sparser spots and appears much more similar to B. maculosus. Coe (1940) wrote that part of the material he identified as B. delineatus var. curtus differed from B. delineatus in having ‘ markings composed of small red or brown dots’, suggesting that the former taxon might include B. maculosus. Baseodiscus aff. maculosus seems to feed on terebellid polychaetes (see Potential food items below).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE76ED58FCBACFC9FB9EFB72.taxon	description	(FIG. 3 C – E)	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE76ED58FCBACFC9FB9EFB72.taxon	materials_examined	Material examined: Five specimens (extracted total DNA and remaining body preserved in 99 % EtOH): four specimens (including ICHUM 6325), 22 February 2014, rocky intertidal, under stone, near Misaki Marine Biological Station (35 ° 09 ′ 30 ″ N, 139 ° 36 ′ 45 ″ E), collected by H. Kajihara; one specimen (ICHUM 6326), 26 March 2014, rocky intertidal, under stone, Araihama (35 ° 09 ′ 33 ″ N, 139 ° 36 ′ 40 ″ E), Misaki, Kanagawa, Japan, collected by H. Kohtsuka. Sequences: From ICHUM 6325: LC 178621, 28 S (1136 bp); LC 178665, 16 S (521 bp). From ICHUM 6326: LC 178647, H 3 (331 bp); LC 178666, 16 S (521 bp). Description: Body up to 56 cm long, 3 mm wide (ICHUM 6325); background body colour pale beige, with pale-brown longitudinal stripes covering entire body (Fig. 3 C, D) except near mouth (Fig. 3 E). Distribution: Warm waters worldwide: France (Joubin, 1890, 1894), Italy (Delle Chiaje, 1822 – 29; Grube, 1840; Hubrecht, 1879; Bürger, 1895 a; Strand et al., 2005), Australia (Strand et al., 2005; Kvist et al., 2014), Japan (Kajihara, 2017; Ikenaga et al., 2019), Florida, USA (Schwartz, 2009), Belize (Schwartz, 2009), Panama (Schwartz, 2009), Colombia (Gonzalez-Cueto et al., 2014), Brazil (Mendes et al., 2016). Remarks: In accordance with Article 12.2.7 of the Code (ICZN, 1999), the year of publication for B. delineatus should be 1822, rather than 1825 as previously regarded (e. g. Magarlamov & Chernyshev, 2011; Ikenaga et al., 2019). The species was originally established as Polia delineata in Delle Chiaje (1822 – 29), a work comprised of plates published in 1822 and four text volumes, with Volumes 1 and 2 issued in 1825 [or, Volume 2 may have been published in 1827 (Neave, 1940: 344)], Volume 3 in 1828 and Volume 4 in 1829. The description in words appeared in Volume 2 on p. 409 (as ‘ P. lineata ’) and pp. 427 – 428 (Delle Chiaje, 1825 in 1822 – 29), although the species name Polia delineata had already appeared as the caption for an plate illustration published in 1822. Delle Chiaje’s 1822 plate numbers are discontinuous in several places: plate numbers XXX (30), LXIII (63) and CII (102) are missing; in addition, for each of the four numbers I (1), II (2), XXVIII (28) and XXXIV (34), two different plates exist. Polia delineata is depicted on the second of the two plates labelled XXVIII.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE76ED58FCBACFC9FB9EFB72.taxon	description	Bürger (1895 a: 600) synonymized Borlasia carmellina Quatrefages, 1846 (type locality, Favignana Island, Italy) with Eupolia delineata, but there are some differences between the descriptions of the two: in Borlasia carmellina, the body is reddish posteriorly and covered with small, elongate patches (‘ petites taches allongée’) rather than stripes, and eyes are lacking (Quatrefages, 1846).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE75ED59FC7CCB71FDB8FC93.taxon	description	(FIG. 7 D, E) Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org: act: 5 DBE 9 E 10 - 9 A 24 - 447 B- 9 A 7 F-EE 5 DD 10891 E 0. Material examined: Holotype, ICHUM 6327, 29 May 2001 off Toi Cape (31 ° 19 ′ 12 ″ N, 131 ° 21 ′ 00 ″ E), Kagoshima, Japan, 118 m depth, station 12 of the R / V Toyoshio-maru Cruise 01 - 06, collected by H. Kajihara. Sequences: From the holotype: LC 178592, 18 S (1799 bp); LC 178622, 28 S (2117 bp); LC 178667, 16 S (456 bp); LC 190945, COI (629 bp). Etymology: The new specific name is a noun in the genitive case, from Prof. Susumu Ohtsuka, a Japanese crustacean biologist, leader of marine biodiversity studies with the R / V Toyoshio-maru of Hiroshima University. Description: Body broad, dorsoventrally flattened, 15 cm long, 4 mm wide; ground colour white, dorsally with wide purplish brown stripe, ventrally with minute flecks of same colour (lacking in front of cephalic furrow); transverse cephalic furrow present, encircling neck; secondary furrows present; small, black ocelli distributed along dorso-lateral surfaces of head; proboscis pore sub-terminal; mouth small (Fig. 7 D, E). Found in mucus tube formed with mud and sand particles. Distribution: So far known only from the type locality, sublittoral, off southern Kyushu in the Pacific (present study). Remarks: Baseodiscus ohtsukai looks similar to B. urgorrii in that it has a whitish background colour and a broad, mid-dorsal longitudinal stripe, but differs from the latter in the colour of the stripe, which is more reddish than that in B. urgorrii.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE74ED66FF3DCDFAFE6DF983.taxon	description	(FIG. 3 F)	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE74ED66FF3DCDFAFE6DF983.taxon	materials_examined	Material examined: Two specimens, ICHUM 6328, 6329, 12 November 2003, subtidal, ~ 2 m depth, among shells of the cultured oyster Magallana gigas (Thunberg, 1793), Hiroshima Bay (c. 34 ° 23 ′ N, 132 ° 10 ′ E), Japan, collected by H. Kajihara. Sequences: From ICHUM 6328: LC 178663, 16 S (507 bp); LC 190943, COI (615 bp). From ICHUM 6329: LC 178591, 18 S (1798 bp); LC 178620, 28 S (2097 bp); LC 178664, 16 S (507 bp); LC 190944, COI (658 bp). Description: Body up to 17 cm long, 4 mm wide; background body colour cream white; dorsally mottled with narrow, longitudinal, broken, reddish brown stripes; ventrally without markings (Fig. 3 F). Distribution: Baseodiscus cf. curtus in the sense of this study has been reported from Japan (Takakura, 1898; Iwata, 1952; Kajihara, 2017; present study). Baseodiscus curtus s. s. has been reported from Italy (Hubrecht, 1879; Bürger, 1892, 1895 a; Corrêa, 1956) and the Mediterranean coast of France (Timofeev, 1911). Remarks: Considering the geographic distance between Italy and Japan, application of the name curtus to our material from Japan needs confirmation with barcode sequences from topotypes from Naples. If our specimens are actually B. curtus, then the species is different from B. delineatus, as Crandall et al. (2002: 3) noted, although Gibson (1995: 479) synonymized these two species. Hubrecht (1879: 209) established Polia curta, which was supposedly ‘ Distinguished from the foregoing (= Polia delineata = Baseodiscus delineatus) by its greater width in comparison to its length. The brown stripes are much more closely set on the back, 12 – 15 being counted in a transverse line on the back. The belly remains white; only in the largest examples it becomes striped too, the region of the mouth and undersurface of the head always excepted. In young examples the stripes are yet stellate pigment specks, whereas at the same age they are stripes already in Polia delineata. ’ Under the name Eupolia curta, Bürger (1892, 1895 a) referred to four different forms from Naples, as follows: (1) small, 0.5 – 2.0 cm long, light yellow ground colour, speckled with dark brown dots in anterior part of body, probably only dorsally (Bürger, 1895 a, pl. 4, fig. 3); (2) the most common type, co-occurring with B. delineatus, 5 – 6 cm long, 2.5 mm wide, yellow grey in ground colour, dorsally marked with brown, reticular longitudinal stripes; a larger specimen was 10 cm long, 4 mm wide, with longitudinal stripes also present on ventral surface of body (Bürger, 1895 a, pl. 4, fig. 7); (3) bulky, broad form, 15 cm long, 8 – 9 mm wide, vermilion red in background body colour, with fine, yellow reticular pattern both dorsally and ventrally [not obvious in Bürger’s (1895 a, pl. 4, figs 5, 5 a) illustration], head light yellow on dorsal margins, deep yellow ventrally, with short yellow line extending for 1 cm mid-ventrally at anterior end of body; same as Joubin’s (1890) form reported from Banyulssur-Mer, France; and (4) ventrally snow white in colour, 6 – 7 cm long, 3 mm wide (Bürger, 1895 a, pl. 4, fig. 17). Our specimens from Japan agree with Hubrecht’s (1879) original description, as well as with Bürger’s (1895 a) form iv (with snow-white underside) in that the brown longitudinal stripes are lacking on the ventral surface of the body. The taxonomic identity of Bürger’s (1895 a) forms i, ii, and iii need to be investigated with molecular data. There are various records of valenciniid heteronemerteans under the name curtus, curta or curtum from different parts of the world, with a varying degree of reliability in terms of taxonomic identity. Verrill (1900) reported a form as Taeniosoma curtum from Bermuda; slenderer than B. curtus and lacking dorsal stripes on the head in front of the cephalic furrows, it thus appears to be a different species. Joubin (1904) did not mention whether stripes were also present on the ventral surface of the body in material from Djibouti that he identified as Eupolia curta; it could have been either B. curtus or another species such as B. delineatus. Timofeev (1911: 39) provided no information on the body colour of his ‘ Baseodiscus curtus ’ from Villefranche-sur-Mer, the identity of which cannot be confirmed. StiasnyWijnhoff (1925) admitted that her specimens from Curaçao, which she identified as B. curtus, were also consistent with B. delineatus in having stripes also on the ventral surface of the body. Coe (1940) regarded curtus as a variety of B. delineatus, listing (Coe, 1940: 261) the distribution as ‘ Mediterranean, East Indies, Polynesia, Mauritius, Bermuda, West Indies, on the Pacific coast in the Gulf of California, and on the coast of Chile’. Coe (1940) mentioned that the body markings in B. delineatus var. curtus comprise small, red or brown dots or larger spots without definite pattern, instead of interlacing longitudinal lines. These markings are also seen in B. maculatus, B. maculosus and B. amboinensis, suggesting that Coe’s (1940) B. delineatus var. curtus probably included several species. Corrêa (1956) reported three specimens from Naples that she identified as B. curtus [Bürger’s (1895 a) form ii], although they also had stripes also on the ventral body surface. Gibson’s (1974) material from Jidda, reported as B. curtus, is more similar to B. insignis Punnett & Cooper, 1909 from Zanzibar in that the stripes, also present ventrally, are discontinuous beyond and behind the cephalic furrow; this also applies to what Gibson (1979) identified as B. delineatus from the Great Barrier Reef.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE4BED66FF0EC801FBC3FC7C.taxon	materials_examined	Material sequenced: Two specimens (DNA vouchers ICHUM 6330, 6331); 16 February 2009, Tumbes (36 ° 37 ′ 50 ″ S, 73 ° 05 ′ 26 ″ W), Chile, collected by P. Sundberg; one of the two is equivalent to ‘ NemBar 0920 ’ in Sundberg et al. (2016 b). Sequences: From ICHUM 6330: LC 178587, 18 S (1796 bp); LC 178615, 28 S (2040 bp); LC 178658, 16 S (505 bp); LC 190939, COI (598 bp). From ICHUM 6331: LC 178588, 18 S (1797 bp); LC 178616, 28 S (2042 bp); LC 178659, 16 S (505 bp). Distribution: South-western Pacific. Peru (Bürger, 1896) and Chile (Bürger, 1896; Isler, 1900; Friedrich, 1970; Thiel & Norenburg, 2009; present study). Remarks: Thiel & Norenburg (2009: 377) placed Baseodiscus platei (Bürger, 1896) in the synonym list of Baseodiscus aureus (Bürger, 1896) with uncertainty. It remains to be determined whether B. platei is distinct from B. aureus.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE4BED66FC7ECD80FB3DFB80.taxon	description	(FIGS 3 G, H, 7 F, G)	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE4AED64FC75CD0CFEECFD36.taxon	description	(FIG. 3 I)	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE4AED64FC75CD0CFEECFD36.taxon	materials_examined	Material sequenced: Two specimens (DNA vouchers ICHUM 6332, 6333); Santa Barbara, California, USA, collected by S. A. Maslakova and T. C. Hiebert in 2013. Sequences: From ICHUM 6332: LC 178601, 18 S (1797 bp); LC 178631, 28 S (2120 bp); LC 178679, 16 S (505 bp); LC 190953, COI (658 bp). From ICHUM 6333: LC 178632, 28 S (2057 bp); LC 178680, 16 S (504 bp); LC 190954, COI (658 bp). Description: From a photograph of a specimen that is different from those sequenced but certainly represents the same species, the body is dorsoventrally dark red, posteriorly becoming pale brown (Fig. 3 I). Hiebert (2016: 43 – 44) described, ‘ Pale pink to magenta or red body colour, colour is more pale ventrally; head shape orbicular; conspicuous constriction between head and body marked with oblique cephalic furrows; secondary cephalic furrows present; longitudinal cephalic slits absent; pale colour present at head margins is narrow at anterior tip and widens just anterior to constriction between head and body; many ocelli (80 – 120, total) are present and visible within the pale region of the head; head can withdraw almost completely into body; body is large, fleshy and wrinkly; rounded anteriorly and slightly flattened posteriorly, in cross-section; caudal cirrus absent. Dark brown or black pigment was noted anteriorly and dorsally by Coe (1904), but this has not been observed by us. ’ Distribution: From Monterey Bay, California to Mexico (Coe, 1904, 1905, 1940; Joubin, 1905; Roe et al., 2007; Hiebert, 2016). R e m a rk s: O r i g i n a l l y d e s c r i b e d f r o m m a t e r i a l dredged from 50 fathoms (91 m) depth between San Pedro and Santa Catalina Island, California, USA (Coe, 1904).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE49ED64FEF9CCBFFF2FF8DC.taxon	description	(FIG. 3 J, K) Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. o r g: a c t: 9 7 0 3 B 1 F D - 6 E 5 8 - 4 7 4 A - A 0 7 0 - 774 EB 904159 D. Material examined: Holotype, ICHUM 6334, 26 May 2014, off Oki Island, Sea of Japan (between 34 ° 04 ′ 36 ″ N, 129 ° 59 ′ 13 ″ E and 34 ° 04 ′ 32 ″ N, 129 ° 59 ′ 24 ″ E), 93 m depth, collected by K. Kakui on cruise # 2014 - 06 of the R / V Toyoshio-maru. Sequences: From the holotype: LC 178603, 18 S (1773 bp); LC 178635, 28 S (2102 bp); LC 178684, 16 S (506 bp); LC 190956, COI (658 bp). Etymology: The new specific name, a noun in the genitive case, refers to the collector of the holotype, Dr Keiichi Kakui (Hokkaido University), a Japanese tanaidacean systematist. Description: Background body colour dark yellow, gradually tinged brownish mid-dorsally. Body of holotype 6.6 cm long, 2.4 mm wide (posterior end lacking) (Fig. 3 J). Margins of dorsal brown colour evident on head; small, black eyes arranged on dorsolateral surfaces of head (Fig. 3 K). Distribution: Known only from the type locality, Sea of Japan (present study). Remarks: Baseodiscus kakuii was the sister-taxon to the clade containing B. aureus, B. cf. curtus, B. urgorrii, and Clades B and C in our ML tree (Fig. 1). The body coloration of B. kakuii resembles that of B. nipponensis, but the former is more yellowish and darker, and has the eyes more pronounced, than the latter.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE49ED65FC80CEB8FDA4FCF6.taxon	description	(FIG. 3 L, M) Material examined: Three specimens. ICHUM 6335, extracted DNA and remaining body preserved in 99 % EtOH; 21 July 2012, dredged off Miyako (between 39 ° 38 ′ 37 ″ N, 142 ° 11 ′ 02 ″ E, 197 m depth, and 39 ° 37 ′ 58 ″ N, 142 ° 10 ′ 43 ″ E, 193 m depth), Pacific coast of Honshu, Japan, collected by K. Kakui at station ‘ kago- 11 ’ on a research cruse of the R / V Soyo-maru. ICHUM 6336, extracted DNA and remaining body preserved in 99 % EtOH; 18 July 2013, dredged off Miyako (between 39 ° 37 ′ 52 ″ N, 142 ° 18 ′ 13 ″ E, 517 m depth, and 39 ° 37 ′ 08 ″ N, 142 ° 17 ′ 42 ″ E, 545 m depth), Pacific coast of Honshu, Japan, collected by K. Kakui at station ‘ kago- 2 ’ of the R / V Soyo-maru. One specimen (DNA voucher ICHUM 6337), 7 July 2011, off Kuril Island (44 ° 36.62 ′ N, 146 ° 26.35 ′ E), Ekaterina Strait, 200 m depth, collected by A. V. Chernyshev during cruise 41 of the S / V Akademik Oparin. Sequences: From ICHUM 6335: LC 178589, 18 S (1740 bp); LC 178617, 28 S (2101 bp); LC 178660, 16 S (505 bp); LC 190940, COI (658 bp). From ICHUM 6336: LC 178618, 28 S (2097 bp); LC 178661, 16 S (505 bp); LC 190941, COI (658 bp). From ICHUM 6337: LC 178590, 18 S (1797 bp); LC 178619, 28 S (2089 bp); LC 178662, 16 S (505 bp); LC 190942, COI (658 bp). Description: Background colour white, dorsally covered with broad, brown longitudinal stripe having numerous tiny perforations through which background colour can be seen; body up to 8 cm long (Fig. 3 L, M). Distribution: North-west Pacific, off Kuril Island (200 m) and off Miyako, Honshu, Japan (193 – 545 m) (present study). Baseodiscus princeps s. s. was originally described from three different places in Alaska, USA: Cape Fox, Yakutat and Orca (Prince William Sound) (Coe, 1901 a). Remarks: Although the PTP / bPTP analyses suggested that the three forms herein labelled B. aff. princeps, B. nipponensis and B. cf. princeps are distinct, they are genetically closely related to one another. Uncorrected p - distances for 16 S between B. aff. princeps and B. nipponensis were 1.39 – 1.59 %, between B. nipponensis and B. cf. princeps 1.19 – 1.39 %, and between B. aff. princeps and B. cf. princeps 0.99 – 1.39 %; those for COI between B. aff. princeps and B. cf. princeps were 4.40 – 4.71 % (Table 4). These values are smaller than those between other heteronemerteans that have been confirmed to be biologically distinct by cross-fertilization experiments: between Maculaura alaskensis and M. oregonensis, 4.0 % for 16 S and 14.3 % for COI (Hiebert & Maslakova, 2015); between Kulikovia alborostrata and Kulikovia fulva, 2.8 % for 16 S and 14.4 % for COI (Ikenaga et al., 2019).	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE48ED65FF22CDEDFC6AFC58.taxon	description	(FIG. 3 N)	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE48ED65FF22CDEDFC6AFC58.taxon	materials_examined	Material examined: ICHUM 6338, extracted DNA and remaining body preserved in 99 % EtOH; 19 February 2014, dredged from Sagami Bay (between 35 ° 05 ′ 57 ″ N, 139 ° 34 ′ 52 ″ E, 249 m depth and 35 ° 05 ′ 47 ″ N, 139 ° 34 ′ 05 ″ E, 309 m depth), Japan, station 2 of the 2 nd JAMBIO Coastal Organism Joint Survey (Nakano et al., 2015), collected by H. Kajihara. Sequences: From ICHUM 6338: LC 178630, 28 S (1121 bp); LC 178677, 16 S (505 bp). Description: Body length 3.5 cm, width 1 mm; dorsally reddish brown, ventrally white; eyes present; cephalic furrow encircling head; secondary furrows present (Fig. 3 N). Distribution: So far known only from Sagami Bay, Japan (Hubrecht, 1887; Kajihara, 2017; present study). Remarks: Hubrecht’s (1887) material of Eupolia nipponensis was dredged from green mud at a depth of 345 fathoms (about 640 m) on 12 May 1875 by HMS Challenger in Sagami Bay (35 ° 11 ′ 00 ″ N, 139 ° 28 ′ 00 ″ E). Three body fragments were illustrated by Hubrecht (1887: pl. I, figs 4, 5, 10). Although nothing is mentioned about the size and coloration of these specimens, they were probably small (probably a few centimetres) and devoid of colour pattern, although Hubrecht (1887: fig. 5) may have illustrated the dorsal pigmentation that is also seen in our specimen (ICHUM 6338) from a depth of 309 m in Sagami Bay. Judging from the body size, our specimen (3.5 cm long) was probably a juvenile.	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE48ED62FC6BCA54FE94F8DE.taxon	description	(FIG. 3 O – Q)	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
038A8132EE48ED62FC6BCA54FE94F8DE.taxon	materials_examined	Material examined: Three specimens. ICHUM 6339, extracted DNA and remaining body preserved in 99 % EtOH; 12 June 2012, intertidal, under boulder, Daikoku-jima (42 ° 57 ′ 39 ″ N, 144 ° 52 ′ 31 ″ E), Hokkaido, Japan, collected by H. Kajihara. One specimen (DNA voucher: ICHUM 6340), 8 July 2011, off Iturup Island (44 ° 53.05 ′ N, 147 ° 15.18 ′), 114 m depth, collected by A. V. Chernyshev during cruise 41 of the S / V Akademik Oparin. One specimen (DNA voucher ICHUM 6341), 25 July 2005, Aniwa Bay (46 ° 06.9 ′ N, 142 ° 15.7 ′ E), 25 m depth, collected by A. V. Chernyshev during cruise 31 of the S / V Akademik Oparin. Sequences: From ICHUM 6339: LC 178604, 18 S (1785 bp); LC 178636, 28 S (2119 bp); LC 178685, 16 S (503 bp); LC 190957, COI (658 bp). From ICHUM 6340: LC 178605, 18 S (1797 bp); LC 178637, 28 S (2090 bp); LC 178686, 16 S (503 bp); LC 190958, COI (658 bp). From ICHUM 6341: LC 178606, 18 S (1796 bp); LC 178638, 28 S (1202 bp); LC 178687, 16 S (503 bp); LC 190959, COI (658 bp). Description: Background body colour bright yellow, dorsally mottled with irregular, light-brown patches often intensively fused together, especially in anterior part of body; dorsal mottling may extend ventrolaterally or even ventrally; body up to 30 cm long (Fig. 3 O – Q). D i s t r i b u t i o n: N o r t h - w e s t Pa c i f i c: i n t e r t i d a l, Akkeshi, Hokkaido, Japan (Yamaoka, 1940; present study); subtidal, Far East Russia, Aniwa Bay (25 m) and off Iturup (114 m) (present study). Baseodiscus princeps s. s. was originally described from Alaska (Cape Fox, Yakutat, Orca), USA (Coe, 1901 a). Remarks: This species was first reported as Baseodiscus curtus by Yamaoka (1940) from Daikokujima, Akkeshi Bay, Hokkaido, Japan. Iwata (1954) applied the name Baseodiscus princeps to it. As Chernyshev (2008) pointed out, specimens from Far Eastern Russia differ from B. princeps s. s. in that the dark-coloured markings are present not only dorsally, but also ventrally. Barcode sequences from topotypes should eliminate this uncertainty as to the application of the name princeps. POTENTIAL FOOD ITEMS Unidentified terebellid polychaete sequences were detected by BLASTn searches against the NCBI database of COI sequences derived from ICHUM 6315 and ICHUM 6316 (B. hemprichii), ICHUM 6320 (B. quinquelineatus) and ICHUM 6322 (B. aff. marmoratus), and a 28 S sequence from ICHUM 6324 (B. aff. maculosus), each with ~ 85 % identity values. Some of the cloned COI sequences (658 bp) from ICHUM 6310 (B. narusei) were 99 % identical (differing by two bases in 658 bp) with AB 430534, from an octopus identified by Kaneko et al. (2011) as Octopus cyanea Gray, 1849. Chernyshev & Polyakova (2018: 124) stated: ‘ Some sequences isolated in the process of cloning of COI sequences from the specimen of Sonnenemertes cantelli 38 DS belonged apparently to its prey (according to BLAST search, it is an unknown sipunculid – GenBank MF 512129). Moreover, a COI sequence (GenBank MF 512130) of a similar sipunculid was detected in the specimen of S. cantelli 31 DS through direct sequencing. ’	en	Kajihara, Hiroshi, Abukawa, Shushi, Chernyshev, Alexei V. (2022): Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea). Zoological Journal of the Linnean Society 196: 503-548, DOI: 10.1093/zoolinnean/zlac015
