taxonID	type	description	language	source
2964E41DFFBCFFC8FCE6C000FC28B432.taxon	diagnosis	Diagnosis (after Rodríguez et al. (2008) with modifications in italics). Enthemonae with basilar muscles and mesogleal marginal sphincter; column commonly smooth, rarely tuberculate or with papillae. Tentacles regularly arranged; their aboral sides sometimes with nematocysts batteries, sometimes thickened. Mesenteries not divisible into macro- and microcnemes. Younger mesenteries not bilaterally arranged. Retractor muscles diffuse, rarely circumscribed. No acontia. Cnidom: gracile spirocysts, basitrichs and b - mastigophores and p - mastigophores A. Type genus: Actinostola Verrill, 1883. Other valid genera: Antholoba Hertwig, 1882 (?); Anthosactis Danielssen, 1890; Antiparactis Verrill, 1899; Bathydactylus Carlgren, 1928; Chitinactis; Cnidanthus Carlgren, 1927; Glandulactis Riemann- Zürneck, 1978; Hadalanthus; Hormosoma; Ophiodiscus Hertwig, 1882; Paranthus Andres, 1883 (?); Parasicyonis Carlgren, 1921; Pseudoparactis Stephenson, 1920; Pycnanthus McMurrich, 1893; Sicyonis; Stomphia; Synsicyonis Carlgren, 1921; Tealidium Hertwig, 1882. Remarks: We follow the circumscription given by Rodríguez et al. (2008) for Actinostolidae, except for the addition of genus Glandulactis to the family and removal of Cnidanthea Carlgren, 1959 now included in the family Isanthiidae Carlgren, 1938 (Metridioidea) following Fautin (2016). The question mark after genera Antholoba and Paranthus reflects the uncertainty in their taxonomic placement due to every molecular phylogenetic analysis to date placing them within the superfamily Metridioidea (e. g. Lauretta et al., 2014; Rodríguez et al., 2014; Grajales & Rodríguez, 2016; Gusmão et al., 2018, 2019, 2020). The diagnosis of Actinostolidae was not required to be modified by the inclusion of the new genus Chitinactis.	en	Gusmão, Luciana C., Rodríguez, Estefanía (2021): Two sea anemones (Cnidaria: Anthozoa: Actiniaria) from the Southern Ocean with evidence of a deep-sea, polar lineage of burrowing sea anemones. Zoological Journal of the Linnean Society 193: 1392-1415, DOI: 10.1093/zoolinnean/zlaa176, URL: https://doi.org/10.1093/zoolinnean/zlaa176
2964E41DFFBCFFC8FF29C537FBF1B2E5.taxon	diagnosis	Diagnosis (after Gusmão et al. (2019) with additions in italics). Enthemonae usually with basilar muscles, mesogleal marginal sphincter and no acontia or acontioids; rarely lacking basilar muscles and marginal sphincter muscle. Aboral end mostly flat and adherent; sometimes with physa. Column usually smooth; rarely with cuticle and rows of tubercles. Mesenteries usually not differentiated into macro- and microcnemes; rarely differentiated into macro- and microcnemes. Mesenteries of same pair often unequally developed. Retractors usually diffuse weak or strong, sometimes circumscribed. Cnidom: gracile spirocysts, basitrichs, holotrichs, b - mastigophores and p-mastigophores A. Included families: Actinostolidae, Exocoelactinidae, Halcampoididae and Halcampulactidae. Remarks: We modified the diagnosis of the superfamily Actinostoloidea to reflect the characters observed in the new species (Chitinactis marmara; e. g. rows of tubercles formed by thickenings of mesoglea and strong cuticle on column). In addition, we modified the superfamilial diagnosis to reflect recent changes in the higher level classification of Actiniaria (i. e. Rodríguez et al., 2014) and the nematocyst terminology used in this study (see: Gusmão et al., 2018). These modifications have been made in all other diagnoses included in this study.	en	Gusmão, Luciana C., Rodríguez, Estefanía (2021): Two sea anemones (Cnidaria: Anthozoa: Actiniaria) from the Southern Ocean with evidence of a deep-sea, polar lineage of burrowing sea anemones. Zoological Journal of the Linnean Society 193: 1392-1415, DOI: 10.1093/zoolinnean/zlaa176, URL: https://doi.org/10.1093/zoolinnean/zlaa176
2964E41DFFBCFFCBFC04C746FCD8B0D7.taxon	diagnosis	Diagnosis: Actinostolidae with a broad base. Column low, firm, slightly rugose, with rows of mesogleal tubercles. Margin distinct. Sphincter mesogleal, strong. Tentacles without aboral thickenings or batteries of nematocysts; mesogleal longitudinal musculature in tentacles. Considerably more mesenteries proximally than distally; one cycle of perfect mesenteries. Younger cycles of mesenteries with unequal development between members of the pairs. Retractors well developed, diffuse; strong parietobasilar and basilar musculature. Cnidom: gracile spirocysts, basitrichs, b - mastigophores and p - mastigophores A. Type species: Chitinactis marmara by original designation. Etymology: From chitine the Latinized form of the Greek χιτών, a tunic, referring to the thick cuticle covering species of this genus, and the Latinized Greek suffix - actis, from ακτίνα, a ray. The gender is feminine.	en	Gusmão, Luciana C., Rodríguez, Estefanía (2021): Two sea anemones (Cnidaria: Anthozoa: Actiniaria) from the Southern Ocean with evidence of a deep-sea, polar lineage of burrowing sea anemones. Zoological Journal of the Linnean Society 193: 1392-1415, DOI: 10.1093/zoolinnean/zlaa176, URL: https://doi.org/10.1093/zoolinnean/zlaa176
2964E41DFFBFFFC4FF45C23EFC06B033.taxon	description	(FIGS 3 – 5; 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. org: act: BE 47 D 4 D 3 - 33 D 1 - 47 E 9 - 84 A 6 - CE 5 AF 0 C 96 A 51 Material: Holotype AMNH _ IZC 00331556 (1 specimen), ANT XV / 3 Cruise, EASIZ II Program, R / V ‘ Polarstern’, Sta. PS 48 / 197, Kapp Norvegia, Antarctica, Southern Ocean, 71 ° 17 ’ S 12 ° 36.30 ’ W, 416 m, 15 February 1998, Agassiz Trawl, collected by P. López-González. Paratypes AMNH 4775 (five specimens), same collection data as holotype. AMNH 4662 (one specimen), ANT XIX / 5 Cruise, LAMPOS Program, R / V ‘ Polarstern’, Sta. PS 61 / 150, Burdwood / Namuncurá Bank, Scotia Sea, Antarctica, Southern Ocean, 54 ° 30.22 ’ S 56 ° 08.20 ’ W, 286.3 – 290.3 m, 6 April 2002, Agassiz Trawl, collected by E. Rodríguez. AMNH 4663 (ten specimens), ANT XIX / 5 Cruise, LAMPOS Program, R / V ‘ Polarstern’, Sta. PS 61 / 153, Burdwood / Namuncurá Bank, Scotia Sea, Antarctica, Southern Ocean, 54 ° 31.22 ’ S 56 ° 08.93 ’ W, 277 – 296 m, 6 April 2002, Bottom Trawl, collected by E. Rodríguez. AMNH _ IZC 00331550 (one specimen), ANT XXIII / 8 Cruise, EBA Program, R / V ‘ Polarstern’, Sta. PS 69 / 662 - 1, South Shetland Islands, Antarctica, Southern Ocean, 61 ° 35.91 ’ S 57 ° 17.04 ’ W / 61 ° 35.41 ’ S, 57 ° 20.60 ’ W, 425.4 – 431.8 m, 30 December 2006, Bottom Trawl, collected by P. López-González. AMNH _ IZC 00361336 (one specimen), ANT XXIX / 9 Cruise, FOS Program, R / V ‘ Polarstern’, Sta. PS 82 / 283 - 2, Weddell Sea, Antarctica, Southern Ocean, 74 ° 59.61 ’ S 29 ° 22.89 ’ W, 406.7 – 411 m, 7 February 2014, Agassiz Trawl, collected by R. Zapata. AMNH _ IZC 00361337 (one specimen), ANT XXIX / 9 Cruise, FOS Program, R / V ‘ Polarstern’, Sta. PS 82 / 283 - 2, Weddell Sea, Antarctica, Southern Ocean, 74 ° 59.46 ’ S 29 ° 22.75 ’ W, 406.7 – 411 m, 7 February 2014, Agassiz Trawl, collected by R. Zapata. NHMUK (one specimen), JCR 15005, event # 61, NW of Coronation Island, South Orkney Islands, Scotia Sea, Antarctica, 60 ° 21.3180 ’ S 46 ° 41.0820 ’ W, 516.97 m depth, 9 March 2016, Agassiz trawl, collected by E. Rodríguez. Additional material examined for comparison: Stomphia selaginella (Stephenson, 1918): AMNH 4326 (20 specimens); locality: ANT XV / 3 Cruise, EASIZ II Program, R / V ‘ Polarstern’, Sta. PS 48 / 220, Southern Ocean, Antarctica, Weddell Sea, Austasen, 70 ° 50.40 ’ S 10 ° 35.40 ’ W, collected on 19 February 1998 by P. López- González (236 m). Actinostola crassicornis (Hertwig, 1882): AMNH 4698 (three specimens); locality: ANT XIX / 5 Cruise, LAMPOS Program, R / V ‘ Polastern’, Sta. 61 / 153, Drake Passage, Antarctica, Burdwood / Namuncurá Bank, 54 º 31.22 ’ S 56 º 08.93 ’ W, collected on 6 April 2002 by E. Rodríguez (277 m). Actinostola georgiana Carlgren, 1927: AMNH 4803 (one specimen); locality: ANT XXI / 2 Cruise, BENDEX Program, Sta. PS 65 / 019 - 1, Southern Ocean, Bouvet Island, 54 ° 30.09 ’ S 03 ° 14.13 ’ W, collected on 24 November 2003 by E. Rodríguez (247 m). Diagnosis: Species with mesogleal marginal sphincter and tentacular longitudinal musculature, younger mesenteries unequally developed, no acontia and welldeveloped, thick chitinous cuticle on column. Etymology: The species name is Latinized Greek from µάρµαρο, marble. It is named in honour of Pablo López- González (Universidad de Sevilla, Spain). He was the first to collect this species and we thank him for his contributions to the diversity of Anthozoa in the Southern Ocean and his mentoring of systematists working on this group. External anatomy (Fig. 3): Some specimens are flat with triangular body, with elevated central column (Fig. 3 A, B) and broad, flat pedal disc (Fig. 3 B, C), others more elongate (Fig. 3 C). Pedal disc broader than column, irregular in shape (Fig. 2 B) with mesenterial insertions visible on limbus (Fig. 3 C); 9 – 21 mm in diameter in preserved specimens. Column cylindrical, broader proximally, becoming less so distally due to contraction of scapulus into scapus in most specimens (Fig. 3 B, D); in less contracted specimens, column visibly divided into short, smooth scapulus and long scapus (Fig. 3 E); column diameter 5 – 16 mm at midcolumn and 7 – 22 mm length in preserved specimens. Scapus with small tubercles in longitudinal rows throughout scapus (Fig. 3 F); column epidermis may be absent in certain regions (Fig. 3 F). Thick, golden cuticle on column (Fig. 3 A, F); may form a thick ‘ crust’ easily detached from animal (Fig. 3 G); cuticle completely absent from column in some specimens (Fig. 3 C, E). Margin of column tentaculate (Fig. 3 C, E). Oral disc small, circular in contracted specimens; diameter 1 – 3 mm in preserved specimens. Tentacles about 50, slender (Fig. 3 C, E); putatively arranged in four cycles; up to 5 mm in preserved specimens. Internal anatomy, microanatomy (Fig. 4): Aboral end flat, not physa-like (Fig. 4 A). Overall body wall thickness varies along column (Fig. 4 A – C): scapus epidermis 85 – 271 µm, mesoglea 92 – 398 µm and gastrodermis 40 – 190 µm (Fig. 4 D); scapulus epidermis 101 – 169 µm, mesoglea 79 – 248 µm and gastrodermis 91 – 158 µm (Fig. 4 E). Thick, brown, non-stratified cuticle on scapus (Fig. 4 B, C, E), absent from scapulus (Fig. 4 D); cuticle also on pedal disc (Fig. 4 A). Longitudinal circular endodermal musculature of column strong, with high muscle processes in distal column (Fig. 4 F), also observed in dissections (Fig. 4 B, arrow). Mesogleal marginal sphincter musculature (Fig. 4 G). Longitudinal musculature of tentacles mesogleal (Fig. 4 H). Actinopharynx short, strongly longitudinally sulcate (Fig. 4 A); siphonoglyphs not differentiated (Fig. 4 I). Two cycles of mesenteries distally at scapulus-level (Fig. 4 J): six pairs of perfect mesenteries of first cycle and four pairs of second cycle with a single mesentery of a pair in the dorso- and ventral-lateral exoceles (but seen in scapulus: Fig. 4 K). Three cycles of mesenteries at distal column: six pairs of perfect mesenteries of first cycle, two cycles of imperfect mesenteries (6 + 6 + 12: Fig. 4 K, L). More mesenteries proximally than distally (6 + 6 + 12 + 24: Fig. 4 L, N). Retractors of mesenteries of first cycle strong, diffuse (Fig. 4 K, N, O); well developed, pinnate, with well-developed central mesogleal lamella proximally (Fig. 4 P). Retractors of second and third cycles weaker than in first cycle, diffuse, occupying entire mesentery length (Fig. 4 K, N). Mesenteries of fourth cycle small, without well-developed musculature (Fig. 4 P). Parietobasilar musculature well developed, strong in mesenteries of first to third cycles both distally (Fig. 4 O) and proximally (Fig. 4 Q); absent in mesenteries of fourth (Fig. 4 N). Basilar musculature present (not shown). Gametogenic tissue in third cycle mesenteries (Fig. 4 L); specimens collected in December sterile and those in February females. Species inferred gonochoric. Cnidom: spirocysts, basitrichs, b - mastigophores and p - mastigophores A. See Figure 5 and Table 1 for size and distribution. Distribution and natural history: Multiple individuals of Chitinactis marmara were collected around the South Shetland Islands in the Antarctic Peninsula, the south-west of the South Orkney Islands and east of Burdwood / Numuncurá Bank in the Scotia Arc, from 277 – 517 m depth. Specimens of C. marmara were also collected from the eastern Weddell Sea (at Kapp Norvegia) between 400 and 416 m depth, some of them collected together with multiple individuals of Aulactinia sulcata (Clubb, 1902). We consider C. marmara a shelf endemic in Antarctica and sub- Antarctica. The new record of A. sulcata extends the circumpolar distribution of the species found in the Bransfield Strait, South Shetland Islands, Elephant Islands and the Drake Passage in the Antarctic Peninsula and McMurdo Sound (Victoria Island) in the Ross Sea (Rodríguez & López-González, 2013), to include the south-eastern Weddell Sea. Remarks: Chitinactis is a monotypic genus easily differentiated from other actinostolids based on the following combination of characters: mesogleal tubercles and distinct columnar cuticle, mesogleal longitudinal tentacle musculature and unequal development of younger mesenteries. Although the large and common b - mastigophores found in C. marmara (Fig. 5 G) strongly resemble those in the tentacles of some actinostolids (e. g. Hormosoma, Stomphia and Actinostola), they are always only found in the filaments. To date, no specimens having the attributes described for C. marmara have been reported in the literature for the Southern Ocean or anywhere else.	en	Gusmão, Luciana C., Rodríguez, Estefanía (2021): Two sea anemones (Cnidaria: Anthozoa: Actiniaria) from the Southern Ocean with evidence of a deep-sea, polar lineage of burrowing sea anemones. Zoological Journal of the Linnean Society 193: 1392-1415, DOI: 10.1093/zoolinnean/zlaa176, URL: https://doi.org/10.1093/zoolinnean/zlaa176
2964E41DFFB0FFC7FCE6C35FFAC8B2E6.taxon	diagnosis	Diagnosis (after Carlgren, 1949; additions in bold and modifications in italics). Enthemonae with elongate body with proximal end physa-shaped, rarely flat. Column sometimes without regional differentiation, sometimes divisible into physa, scapus and scapulus. No sphincter. Tentacles few up to 40, the inner not shorter than the outer ones. Often with a single siphonoglyph, rarely with two indistinct ones. Perfect pairs of mesenteries variable in number up to 20. Retractors of perfect mesenteries strong, diffuse to restricted, more or less reniform. Parietal muscles distinct. Cnidom: gracile spirocysts, basitrichs, holotrichs, b- mastigophores and p- mastigophores A. Type genus: Halcampoides Danielssen, 1890 I n c l u d e d g e n e r a: A c t h e l m i s L ü t k e n, 1 8 7 5 (?), Calamactinia Carlgren, 1949 (?), Calamactis Carlgren, 1951 (?), Halcampella Andres, 1883 (?), Pentactinia Carlgren, 1900 (?), Scytophorus Hertwig, 1882 and Siphonactinopsis Carlgren, 1921 (?). Remarks: Rodríguez et al. (2012) synonymized Halcampoididae with Halcampidae based on the position of an unidentified species of Halcampoides (type genus of Halcampoididae) as the sister-group to an unidentified species of Halcampa Gosse, 1858 (type genus of Halcampidae). Based on the results of our phylogenetic analyses, we consider Halcampidae and Halcampoididae as separate families (Studer, 1879). Thus, we resurrect family Halcampoididae and reclassify it as an actinostoloidean, given its position in our phylogenetic analysis. We include H. purpureus and S. striatus Hertwig, 1882 until a complete revision of remaining former halcampoidid genera.	en	Gusmão, Luciana C., Rodríguez, Estefanía (2021): Two sea anemones (Cnidaria: Anthozoa: Actiniaria) from the Southern Ocean with evidence of a deep-sea, polar lineage of burrowing sea anemones. Zoological Journal of the Linnean Society 193: 1392-1415, DOI: 10.1093/zoolinnean/zlaa176, URL: https://doi.org/10.1093/zoolinnean/zlaa176
2964E41DFFB3FFC6FC1BC007FD10B416.taxon	diagnosis	Diagnosis (after Carlgren, 1949; modifications in italics). Halcampoididae with elongate body and flat aboral end. Column indistinctly divisible into scapus and scapulus. Cuticle developed chiefly on scapus, with modified weak tenaculi more or less visible to the naked eye. No sphincter. Tentacles 14, with longitudinal muscles ectodermal. A single weak, ventral siphonoglyph without conchula. Mesenteries 14, six pairs plus one couple; individual mesenteries of couple with retractors faced towards dorsal pairs of directives, wherefore there is seemingly a single pair of directives. All mesenteries perfect, with retractors strong, restricted to kidneylike. Parietal muscles well developed. As a rule, all mesenteries fertile. Ciliate tracts of filaments may be discontinuous. Cnidom: spirocysts, basitrichs, p - mastigophores A. Type species: Scytophorus striatus by monotypy. Included species: Scytophorus antarcticus (Pfeffer, 1889) and S. striatus. Remarks: We modified the generic diagnosis by removing the mention of a physa-like structure in members of Scytophorus. Although Hertwig (1882) described S. striatus as lacking a pedal disc and with a round aboral end, all of the S. striatus specimens examined had a distinct flat aboral end (Figs 6 C, 7 A, F) as seen attached to solid substrates (Fig. 6 A). Although most of the specimens of S. striatus observed had their distal column and oral disc contracted, when they are relaxed, the scapulus can be easily distinguished from the rest of the column (see Fig. 6 D). We left in the diagnosis the presence of a weak siphonoglyph, but this structure was difficult to observe in dissections (Fig. 7 G), histological sections or micro-CT scans (Fig. 7 K), as noted by others (e. g. Carlgren, 1921).	en	Gusmão, Luciana C., Rodríguez, Estefanía (2021): Two sea anemones (Cnidaria: Anthozoa: Actiniaria) from the Southern Ocean with evidence of a deep-sea, polar lineage of burrowing sea anemones. Zoological Journal of the Linnean Society 193: 1392-1415, DOI: 10.1093/zoolinnean/zlaa176, URL: https://doi.org/10.1093/zoolinnean/zlaa176
2964E41DFFB2FFC3FF53C771FB06B547.taxon	description	(FIGS 6 – 8; TABLE 2) Material: AMNH 5268 (nine specimens), Nathaniel B. Palmer R / V, NBP 11 - 03 Expedition, Sta. 14, off Burdwood / Namuncurá Bank, Drake Passage, Antarctica, 54 º 42.84 ’ S 62 º 14.99 ’ W, 732 m, 11 May 2011, Hein Dredge, collected by M. R. Brugler. AMNH 5275 (three specimens), ‘ Nathaniel B. Palmer’ R / V, NBP 11 - 03 Expedition, Deep Site – North Grassy Knoll, Sta. 10, Burdwood / Namuncurá Bank, Drake Passage, Antarctica, 54 ° 43.35 ’ S 62 ° 14.21 ’ W, 720 m, 11 May 2011, Blake Trawl, collected by M. R. Brugler. AMNH 5254 (20 specimens), Nathaniel B. Palmer R / V, NBP 11 - 03 Expedition, Sta. 16, off Burdwood / Namuncurá Bank, Drake Passage, Antarctica, 54 º 48.52 ’ S 62 º 07.20 ’ W, 1423 m, 13 May 2011, Hein Dredge, collected by M. R. Brugler. AMNH _ IZC 00361338 (three specimens), Nathaniel B. Palmer R / V, NBP 11 - 03 Expedition, Sta. 22, off Burdwood / Namuncurá Bank, Drake Passage, Antarctica, 54 º 50.50 ’ S 62 º 07.53 ’ W, 1922 m, 14 May 2011, Hein Dredge, collected by M. R. Brugler. Additional material examined for comparison: Scytophorus antarcticus ZMH C 1452 (one specimen: holotype); locality: South Georgia. Halcampoides purpureus AMNH 4498 (one specimen); locality: Southern Ocean, Antarctica, Kapp Norvegia, Sta. PS 56 / 105 - 1, 10 ° 57 ’ S 12 ° 15.05 ’ W, GKG, giant box corer, collected in 2000 by P. López-González bi-layered cuticle on column with foreign material attached to it, p - mastigophores A in actinopharynx. External anatomy (Fig. 6): Body elongate in preserved specimens (Fig. 6 A, B) but with aboral end flattened without a well-defined physa (Fig. 6 A – C). Column cylindrical with 14 longitudinal furrows / evaginations (Fig. 6 B), divided into scapulus and scapus (Fig. 6 D) and tenaculi throughout scapus (Fig. 6 E); column with epidermis covered by yellow cuticle distributed on scapus (Fig. 6 B, E). Column diameter 5 – 11 mm distally and 7 – 9 mm proximally; 18 – 40 mm length in preserved specimens. Oral disc small, circular, contracted in all specimens (Fig. 6 A, B, D); diameter 2 – 7 mm in preserved specimens. Margin of column tentaculate; tentacles 14, smooth; putatively arranged in a single cycle. (330 – 331 m). AMNH 4501 (one specimen); locality: Southern Ocean, Antarctica, Bransfield Strait, Sta. PS 56 / 164 - 1, 63 ° 04.80 ’ S 59 ° 32.80 ’ W, Agassiz Trawl, collected on 28 April 2000 by P. López-González (858 – 859 m). AMNH 4502 (one specimen); locality: Southern Ocean, Antarctica, West Deception Island, Sta. PS 56 / 183 - 1, 62 ° 07.15 ’ S 60 ° 22.60 ’ W, Bottom Trawl, collected on 3 May 2000 by P. López-González (200 – 204 m). Halcampoides abyssorum Danielssen, 1890 USNM 53297 (seven specimens); locality: North Pacific Ocean, Bering Sea, Alaska, Punuk Islands, Stranger M / S, collected on 15 July 1937 by W. Williams (27 m). Diagnosis: Fourteen mesenteries arranged in seven pairs, 14 tentacles, hermaphrodite, strongly attached, Internal anatomy, microanatomy (Fig. 7): Aboral end flat, not physa-like, but without basilar musculature (Fig. 7 A). Overall body wall thickness varies along column: generally thicker on furrows (epidermis 53 – 119 µm, mesoglea 33 – 119 µm, gastrodermis 50 – 122 µm) than rest of column (epidermis 32 – 84 µm, mesoglea 19 – 88 µm, gastrodermis 50 – 94 µm) (Fig. 7 B). Bi-layered cuticle on column (19 – 35 µm) (Fig. 7 B). Longitudinal endodermal musculature of column strong (Fig. 7 C); higher muscle processes in distal column, but not forming a differentiated marginal sphincter muscle (Fig. 7 D). Longitudinal musculature of tentacles ectodermal (Fig. 7 E). Actinopharynx approximately one-third of the length of the column, longitudinally sulcate, more heavily folded proximally (Fig. 7 F). Two indistinct siphonoglyphs (Fig. 7 G, K). Mesenteries with unusual arrangement: 14 perfect mesenteries arranged in seven pairs, including a single pair of directives (Fig. 7 H, I). Macrocnemes span entire length of body, from proximal (Fig. 7 J) to distal column (Fig. 7 L). Retractors of macrocnemes small, strong, circumscript, with clear pennon distally (Fig. 7 M). Parietal musculature well developed, strong (Fig. 7 N), equally developed in all mesenteries (Fig. 7 I), more developed proximally (Fig. 7 L). Basilar musculature absent (Fig. 7 A). The four specimens examined hermaphroditic (Fig. 7 O): one to three oocytes per macrocneme (major axis of oocytes 217 – 597 µm) and many spermatic cysts (major axis of spermatic cysts 94 – 311 µm); all specimens collected in May. Cnidom: spirocysts, basitrichs and p-mastigophores A. See Figure 8 and Table 2 for size and distribution. Distribution and natural history: Over a dozen specimens of Scytophorus striatus were collected in the same trawl suggesting they might be locally abundant in the Burdwood Bank (also known as Namuncurá Bank) at 1423 m. Many of these specimens were collected attached to scleractinian corals (Fig. 6 A) indicating that at least some of them live burrowed in the sand but attached to solid substrates, which were plentiful in the trawl (e. g. coarse sand and coral gravel). The species was collected in an area in which octocorals and stylasterid hydroids were also trawled. Scytophorus striatus was previously known only from its type locality between the Kerguelen Islands and Heard Island and McDonald Islands (52 ° 4 ’ S, 71 ° 22 ’ E) in somewhat shallow waters (274 m). This new record for S. striatus extends the distribution of the species from the Indian Ocean region of Antarctica (Kerguelen) to the Atlantic portion of the sub-Antarctic region (Burdwood / Namuncurá Bank), a region that connects continental South America to the northern region of the Antarctic Peninsula. We also extend significantly the bathymetric range of S. striatus to 720 – 1922 m depth. Scytophorus is one of only six genera found in both Antarctic and sub- Antarctic regions (~ 7 % of Antarctic fauna: Rodríguez et al., 2007). Remarks: Specimens of S cytophorus striatus examined in this study largely agree with the original description in terms of external anatomy and musculature. We document and provide the cnidom and cnidae size ranges of S. striatus for the first time (see Fig. 8 and Table 2) and show that it differs from the one given for S. antarcticus by Carlgren (1927) and our own examination of its holotype (ZMH C 1452; see Fig. 9). Both species differ in the size of basitrichs in the column and the actinopharynx, which in the column only overlaps in the lower range of those in S. striatus, and the presence of p- mastigophores in the actinopharynx in S. striatus. Although Carlgren (1927) does not specify the types of nematocysts in S. antarcticus, we confirmed their identity (Table 2), including those of the mesenterial filaments not provided by him (i. e. basitrichs, p - mastigophores A). One of the most consistent differences between S. antarcticus and S. striatus is fertility: S. antarcticus is gonochoric, whereas S. striatus is hermaphrodite. Although hermaphrodite and gonochoric specimens may coexist in a population, hermaphrodites tend to be rare (e. g. Jennison, 1981; Van Praët, 1990; Rodríguez et al., 2013). The fact that all five specimens of S. striatus examined in this study were hermaphrodite leads us to believe that it is a specific character of S. striatus. Likewise, we confirmed that the holotype of S. antarcticus (ZMH C 1452) is female, corroborating the reproductive differences between the two species.	en	Gusmão, Luciana C., Rodríguez, Estefanía (2021): Two sea anemones (Cnidaria: Anthozoa: Actiniaria) from the Southern Ocean with evidence of a deep-sea, polar lineage of burrowing sea anemones. Zoological Journal of the Linnean Society 193: 1392-1415, DOI: 10.1093/zoolinnean/zlaa176, URL: https://doi.org/10.1093/zoolinnean/zlaa176
