taxonID	type	description	language	source
03F17E4CFF8CFFCAFF30FD22FA165CC9.taxon	diagnosis	Diagnosis (after Allen & Noffsinger 1978; Decraemer et al. 1997, Venekey et al. 2005, emended): Draconematinae. First anterior 7 – 14 annules of the cuticle enlarged. Twelve CATs on rostrum in two transverse rows. Amphids on rostrum, usually loop-shaped in males, open spiral or unispiral in females. No postanal PATs. Type species: Draconema cephalatum Cobb, 1913. The first extensive review of the genus Draconema was undertaken by Allen & Noffsinger (1978). They listed six valid species, two of them were described new for science (D. chilense Allen & Noffsinger, 1978 from Chile and D. antarcticum Allen & Noffsinger, 1978 from Antarctica) and four known species were redescribed from type specimens (D. cephalatum Cobb, 1913, Jamaica) or from specimens from the type or other localities (D. haswelli (Irwin – Smith, 1918), from the type locality of New South Wales, Australia; D. claparedii (Metscnikoff 1867), from Naples, Italy close to the type locality; D. ophicephalum (Claparéde 1863), from Naples, Italy and Marseille, France while the type locality is Normandy, France). Redescriptions of the older species D. claparedii (Metscnikoff, 1867), D. haswelli (Irwin-Smith, 1918) and D. ophicephalum (Claparède, 1863) were supplied with long lists of junior synonyms. Decraemer et al. (1977) reviewed Draconematidae and largely accepted the synonymization of Allen & Noffsinger. They listed seven valid species of Draconema, with the addition of D. japonicum Kito, 1976 (Kito 1976, 1979). A few new Draconema species have been recorded since. Venekey et al. (2005) described two new species D. brasiliensis and D. fluminensis from Brazil and provided a useful table summarizing mensural and numerical characters of all valid species of the genus. Kito & Chatterjee (2012) added a further new species D. andamanense from the coast of Andaman Islands, Indian Ocean, and a dichotomous key for the identification all valid Draconema species known by that time. At about the same time, Rho & Min (2011) recorded the species D. hoonsooi Rho & Kim and D. youngeouni Rho & Kim from around the Korean Peninsula. There are several ambiguities with the two latter species in that publication. First, their scientific names are provided with neither year of publication, nor indication of type material. Second, drawings (habitus) and measurements are given for only one male but 15 males and 11 males were examined respectively for both D. hoonsooi and D. youngeouni. Though the descriptions are detailed and the drawings are fine and apparently precise, we accept here that the names D. hoonsooi and D. youngeouni are invalid based on Paragraph 16.1 of ICZN (1999). A summarized list of ten valid Draconema species is presented below.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF8CFFCDFF30FBE7FDF85FD9.taxon	diagnosis	Diagnosis (emend. after Lorenzen 1994; Allen & Noffsinger 1978; Decraemer et al. 1997): Draconematidae. Body clearly swollen in pharyngeal and midbody regions with distinct narrowing between them. Pharynx dumbbell-shaped, i. e. swollen anterior corpus and posterior bulb with isthmus between them. Buccal cavity small and unarmed. Type genus: Draconema Cobb, 1913.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF8BFFC7FF30FC4DFE815A39.taxon	materials_examined	Material. Ten males and ten females. Locality. White Sea (Northern Russia), Karelian Coast of the Kandalaksha Bay, vicinity of the White Sea Biological Station, Velikaja Salma Strait between the Veliky Island and Kindo Peninsula (66 ° 33 ' N, 33 ° 06 ' E), depth 2 – 5 m, brown and red algae. 18 – 27 August 2013.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF8BFFC7FF30FC4DFE815A39.taxon	description	Description. Body swollen in the middle of pharyngeal region and strongly narrowed just posteriorly at the level of cardia and anterior-most intestine. Male bodies slightly slimmer than that of females. Most specimens bent dorsally in anterior half of the body. Female body noticeably widened in region of the reproductive organs. Body cuticle distinctly annulated along the entire body, thicker in the pharyngeal region and thinner posterior to the cardia. Anterior-most head cuticle smooth, forming rostrum. Length of the rostrum 15 – 39 µ m in males and 17 – 33 µ m in females. Anterior 12 – 14 cuticular annules of the pharyngeal region enlarged (three annules in 10 µ m) and marked with tiny irregular vacuoles along the midline of each annule while remaining posterior annules of the body are 2 – 3 times more narrow (8 – 9 annules in 10 µ m) and look homogeneous. Small mouth opening covered with six rugose lips. Labial region encircled with a tight and narrow hexagonal furrow and then with a wider radially rugose (crumpled) zone (Fig. 3 D). Six short (4 – 5 µ m) inner labial setae situated in the furrow. Six outer labial setae 5 – 6 µ m long located at the outer margin of the rugose zone. Four cephalic setae 16 – 18 µ m long located at level of anterior edge or middle part of amphideal fovea. Numerous somatic (subcephalic) setae on the rostrum mask cephalic setae, hence the cephalic setae may be difficult to distinguish. Amphideal fovea situated at the base of the rostrum in latero-dorsal position. Amphideal fovea large, loop-shaped, dorsal arm slightly longer than ventral, with no difference in shape between males and females. Width of the amphideal fovea 1.6 – 3.2 µ m in males and 1.6 – 2.6 µ m in females. There are about 290 – 300 various non-modified and modified somatic setae along the body. Cephalic adhesive tubes (CATs) long and wide setae bent anteriorly, with bulb-shaped bases and slightly modified tips, situated dorsally on the rostrum. Twelve CATs located in six longitudinally arranged pairs, two dorsal pairs, two subdorsal and two laterodorsal pairs, posterior tube longer than anterior one in each pair (Fig. 3 B). Non-modified thin and flexible somatic setae arranged in eight irregular rows along the body. Longest setae located on pharyngeal region (up to 55 Μ m in males, up to 51 Μ m in females); length of most somatic setae on remainder of body nearly equal in length (32 – 45 Μ m in males, 30 – 45 Μ m in females). Six pairs of setae on annulated part of the tail and 3 – 4 pairs on non-annulated terminal cone of the tail. Posterior adhesive tubes (PATs) present as wide and stiff slightly bent, with bulb-shaped bases and cup-shaped tips. The PATs arranged in two subventral and two latero-ventral rows on the posterior body, anterior to anus. Length of PATs decreases slightly towards posterior end of rows. There are four non-modified hair-like somatic setae inserted in subventral PAT rows; comparable to PATs in length but thinner. Two anterior-most somatic setae in these rows slightly shorter than adjacent PATs; two posterior-most somatic setae slightly longer than adjacent PATs. Buccal cavity small and unarmed. Some orange pigment granules present around the stoma. Pharynx dumbbell-shaped, swollen anteriorly and posteriorly, with a narrowing (isthmus) between the swellings in the middle part of the pharynx. One anterior testis located ventrally to the intestine. Spicules slender, elongate, slightly arcuate, distally pointed and proximally with a capitulum. Gubernaculum a small bar. Four pairs of anal setae: two pairs (short and long) anterior to anus and two pairs (short, conical and long) posterior. Ovaries antidromously reflexed and located ventrally to the intestine. Tail elongate conical, non-annulated terminal part (terminal cone) 28 – 30 % of the total tail length in males and 37 – 42 % in females. Caudal glands extended a little to precaudal region.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF8BFFC7FF30FC4DFE815A39.taxon	diagnosis	Diagnosis. Draconema. Body length 998 – 1676 µ m in males and 1097 – 1700 µ m in females; a 16.7 – 28.6 in males and 13.3 – 16.8 in females. Anterior 12 – 14 cuticular annules of the pharyngeal region enlarged and marked with tiny irregular vesicles, while posterior annules of the body two to three times narrower and homogeneous. Longest somatic setae (up to 57 µ m) located on pharyngeal region. Amphideal fovea loop-shaped, dorsal arm slightly longer than ventral arm. Twelve cephalic adhesive tubes located in six longitudinally arranged pairs. The posterior adhesive tubes arranged in two lateroventral (12 – 19 in males and 12 – 22 in females) and two subventral (14 – 19 in males and 16 – 21 in females) rows on the posterior body before anus. Spicules 70 – 93 µ m, gubernaculum 37 – 62 µ m long.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF8BFFC7FF30FC4DFE815A39.taxon	discussion	Discussion. All Draconema species have overall similarity and differ from one another in fine details, particularly in number of sublateral adhesion tubes. The White Sea species is close to the re-description of D. ophicephalum by Allen & Noffsinger (1978), except for a slight difference in the length of the last subventral adhesive tubes in females (27 – 31 µm vs 21 – 26 µm). We propose that D. ophicephalum should be re-described because it has been collected in a new region (White Sea) remote from the type locality (Mediterranean). Since the synonymization of Allen & Noffsinger (1978) and Decraemer et al. (1997), the known geographic range of D. ophicephalum is wide, including the Mediterranean, Black Sea, English Channel, North Sea, Baltic Sea, Greenland, and Barents Sea. Here, the range is extended to the north-east with the finding of the species in the White Sea.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF86FFC7FF30FF42FD455BB9.taxon	diagnosis	Diagnosis (emend. after Lorenzen 1994; Allen & Noffsinger 1978; Decraemer et al. 1997): Draconematidae. Pharyngeal body region swelling slight or not present. Pharynx without median narrowing (except for Dracognomus). Buccal cavity small to moderately developed, with unclear to conspicuous dorsal tooth. Type genus: Prochaetosoma Micoletzky, 1922.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF85FFC4FF30F986FAD2583E.taxon	diagnosis	Diagnosis (after Allen & Noffsinger 1978; Decraemer et al. 1997, emended): Prochaetosomatinae. Pharyngeal body region only slightly swollen. Rostrum rounded. Six to 14 CATs located just posterior to rostrum. Amphideal fovea loop-shaped to uni- or doubled spiral. PATs all anterior to anus. Pharynx consists of cylindrical corpus and posterior bulb; internal cuticle of the bulb distinctly thickened in most species. Buccal cavity with conspicuous dorsal tooth. Type species: Prochaetosoma primitiva (Steiner, 1916) Micoletzky, 1922.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF85FFC4FF30F986FAD2583E.taxon	discussion	Discussion. In their synthesis of Draconematidae, Decraemer et al. (1997) listed ten species of Prochaetosoma. Some of these species, i. e. P. arcticum (Kreis, 1963), D. lugubre (Gerlach, 1957) and P. primitivum (Steiner, 1916) are known from only a few or a single female and juveniles. The lack of males in the original diagnoses hampers identification because the males, apart from the copulatory apparatus important for species determination, may possess particular precloacal midventral differentiations indicating belonging to a definite species. Therefore, since diagnoses of P. arcticum and P. lugubre miss male characters, and their females are not marked by any clear diagnostic features, both these species are qualified here as species inquirendae. They may be restored as valid species in future if males and females found and re-described from type localities. Decraemer et al. (1997) regarded P. primitivum, the type species of Prochaetosoma Micoletzky, 1922, despite the lack of males, since the single fourth stage juvenile specimen described distinctive characters such as the number of posterior adhesive tubes. Rho et al. (2010) described P. dokdoense, summarized eleven valid species of Prochaetosoma and provided a table and a key for their identification. Almost simultaneously, Rho & Min (2011) described eight additional species (P. beomseomense Rho & Kim, P. brevicaudatum Rho & Kim, P. byungilli Rho & Kim, P. cracense Rho & Kim, P. saheungi Rho & Kim, P. sujungi Rho & Kim, P. supseomense Rho & Kim, P. youngdeokense Rho & Kim). As in the case of Draconema (see above), these species names are accompanied neither with designation of new species nor indication of a former publication of the species. Again, we treat these eight species as invalid.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF84FFDEFF30F989FCB05D55.taxon	materials_examined	Material. Holotype male, six paratype males, seven paratype females. The type specimens are deposited in Senckenberg Institute, Frankfurt am Main (Germany), inventory numbers SMF 17047 (holotype) and SMF 17048 – 17054 (paratypes). Type locality. White Sea (Northern Russia), Karelian Coast of the Kandalaksha Bay, vicinity of the White Sea Biological Station (66 ° 33 ' N, 33 ° 06 ' E), Velikaja Salma Strait between the Veliky Island and Kindo Peninsula, depth 2 – 5 m, red algae. 18 – 27 August 2013.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF84FFDEFF30F989FCB05D55.taxon	description	Description. Body elongate and generally slim. Pharyngeal region slightly swollen, rest of body almost cylindrical in males and elongate spindle-shaped in females (swollen in area of gonads). Curvature of the body of fixed specimens rather variable. Rostrum (or cephalic capsule, anteriormost area with non-annulated cuticle) rounded anteriorly. Body cuticle annulation conspicuous and without ornamentations. Cuticular annulations of the pharyngeal region wider than those of rest of the body. Tail cuticle annulated except for terminal cone. Mouth opening surrounded with six triangular lips and then with zone of rugose (crumpled) cuticle (Fig. 6 D). Inner labial papillae on the lip bases; outer labial papillae on the periphery of the rugose zone. Four cephalic setae rooted at the level of anterior margin of the amphideal fovea. Length of the cephalic setae 6.3 – 9.0 µ m in males and 6.0 – 9.0 µ m in females. Amphideal foveas spirally coiled in 1.5 turns in males and females, 0.7 – 1.0 µ m wide in males and 0.6 – 1.4 µ m wide in females. Numerous somatic setae (about 260 – 280) along the body. Longest somatic setae (34 - 49 µ m in males and 32 - 52 µ m in females) located on pharyngeal region. Somatic setae in intestinal region of the body reach 26 – 45 µ m in length in males and 37 – 49 µ m in females with shorter setae 5.0 – 9.4 µ m in males and 3.5 – 9.0 µ m in females. One or two long subdorsal and several short latero-ventral setae on each side of the tail, 23 – 33 µ m long in males and 11 – 40 µ m in females. Eight strong cephalic adhesive tubes (CATs) arranged in four longitudinal pairs (two dorsal and two subdorsal pairs) located dorsally on the head posterior to the rostrum, on 7 th to 17 th annule. The CATs slightly bent forward; their basal ends shaped as bulb-like butts and distal ends modified as cup-like swellings. Within each pair, posterior CAT slightly longer than anterior. Posterior adhesive tubes (PATs) present as thick, slightly bent to almost straight sticks, proximally swollen and gradually narrowing to bell-shaped distal ends. Latero-ventral PATs slightly longer than subventral ones. PATs arranged in four rows, two subventral and two latero-ventral on body between midbody and anal opening. Two subventral rows extended a bit longer posteriorly than latero-ventral rows. Within each row, length of the PATs gradually reduced posteriorly. Buccal cavity narrow (2.2 – 5.5 µ m wide and 5.4 – 8.5 µ m long in males, 1.7 – 5.9 µ m wide and 6.8 – 12 µ m long in females), weakly sclerotized and armed with a small but conspicuous dorsal triangular tooth in the pharyngostoma. In some specimens, buccal cavity surrounded with accumulations of pigment granules in the epidermis. Pharynx rather short, nearly cylindrical or slightly swollen just anterior to nerve ring and posteriorly terminating as a rounded muscular bulb lacking a distinct valve and without cuticularised lumen. Female reproductive system amphidelphic; ovaries antidromously reflexed and located ventral to the intestine; each uterus often contains one mature ovum. Male reproductive system monorchic, anterior testis situated ventrally to the intestine. Spicules slightly arcuate, long, their proximal ends at the level of penultimate latero-ventral PATs or even at the third PATs from posterior end of the latero-ventral row. The spicules proximally ended with weak, ventrally turned knobs, and distally pointed. Gubernaculum a small but distinct bar thickened at anterior end. No supplementary organs evident. Ten rather short (8 Μ m) uncinate setae posterior to the PATs: three setae located anterior to anus and six to seven posterior to the anus. Tail elongate conical, with distinct terminal cone of non-annulated but slightly rough cuticle.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF84FFDEFF30F989FCB05D55.taxon	diagnosis	Diagnosis. Prochaetosoma. Body length 555 – 839 µ m in males and 601 – 811 µ m in females; a 15 – 21.2 in males and 11.6 – 16.0 µ m in females. Somatic setae longest (32 – 52 µ m) on pharyngeal region and of approximately equal length on rest of body. Amphids spirally coiled with 1.5 turns in males and females. One small but distinct dorsal tooth in stoma; two smaller and less conspicuous subventral teeth may be visible. Four pairs of cephalic adhesive tubes. Eight to eleven latero-ventral posterior adhesive tubes in males and 9 – 13 in females; 8 – 11 subventral posterior adhesive tubes in in males and 8 – 12 in females. No cuticularised lumen in terminal bulb of the pharynx. Spicules 75 – 87 µ m, gubernaculum 13 – 18 µ m long. Differential diagnosis. Prochaetosoma marisalbi sp. n. differs from all valid Prochaetosoma species with the possible exception of P. longicapitatum (Allgén, 1932) by lacking cuticular thickening of pharyngeal bulb internal lumen. Taking into account other characters, P. marisalbi sp. n. is more similar to P. longicapitatum (Allgén, 1932) (re-description of Allen & Noffsinger, 1978) and P. martensi Decraemer, 1989.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF9FFFDEFF30FA7AFADA5A33.taxon	diagnosis	Diagnosis (after Gourbault & Decraemer, 1996): Epsilonematinae. Body ɛ-shaped, with widest regions at level of pharynx and reproductive system. Ambulatory setae slender, almost straight or bent, arranged in four to five longitudinal rows in anterior half of posterior body region; pre- and postvulvar in females but postvulvar ambulatory setae fewer in number or missing at all. Supporting setae present. Rostrum with eight subcephalic setae in most species (six and 16 setae also possible). Amphideal fovea spiral, cryptospiral or almost circular with possible sexual dimorphism in shape.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF9FFFDEFF30FA7AFADA5A33.taxon	materials_examined	Type species: Epsilonema cygnoides (Metschnikoff, 1867) Gerlach & Riemann, 1973.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF9FFFDEFF30FA7AFADA5A33.taxon	discussion	Discussion. The first epsilonematid nematode was described by Metschnikoff (1867) as Rhabdogaster cygnoides. Steiner (1927) replaced the name Rhabdogaster with Epsilonema because of homonymy of the former and established the new family Epsilonematidae. Later, Steiner (1931) published a large work on epsilonematid nematodes from Antarctic and Subantarctic seas where he diagnosed 125 new species, eight new varieties and six new genera based on 134 specimens. That study was criticized by Lorenzen (1973), who recognised only three valid species among Steiner’s decriptions, namely Archepsilonema celidotum Steiner, 1931, Bathyepsilonema drygalskii Steiner, 1931 and Epsilonema cyrtum Steiner, 1931. Decraemer (1991) re-examined Epsilonema specimens of the Steiner’s collection and identified there E. cyrtum Steiner, 1931, formerly declared valid by Lorenzen. She also re-described and re-established E. docidocricum (Steiner, 1931) as valid. Gourbault & Decraemer (1996) reviewed the composition of Epsilonematidae and listed 23 valid species of Epsilonema.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF9FFFDEFF30F8E3FDEF5F21.taxon	diagnosis	Diagnosis (modified after Gourbault & Decraemer, 1996): Epsilonematidae. Ambulatory setae present (except in Perepsilonema), slender, more or less bent and arranged in four to seven longitudinal rows. Head a slightly asymmetrical cone, truncated apically. Pharynx with muscular terminal bulb (except in Triepsilonema). Female reproductive system didelphic with ovaries antidromously reflected (anterior branch only outstretched in Leptepsilonema (partim) and both branches outstretched in Triepsilonema and in some Leptepsilonema species). Type genus: Epsilonema Steiner, 1927.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF9EFFD6FF30FE6DFAE35D9D.taxon	materials_examined	Material. Ten males and ten females. Locality. White Sea (Northern Russia), Karelian Coast of the Kandalaksha Bay, vicinity of the White Sea Biological Station (66 ° 33 ' N, 33 ° 06 ' E), Velikaja Salma Strait between the Veliky Island and Kindo Peninsula, depth 5 m, red algae. 18 – 27 August 2013.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF9EFFD6FF30FE6DFAE35D9D.taxon	description	Description. Body ε-shaped and narrowest in the region of the ventral bend between pharynx and anterior gonad. Male body widest in pharyngeal region. Female body widest in region of reproductive system. Head rostrum (cephalic capsule) small, conoid, formed by smooth, uniformly thick cuticle (Fig. 10 A, B). Somatic cuticle posterior to rostrum distinctly annulated. Annules decrease in width to mid-body and then increase again: there three annules in 10 µm on anterior body just posterior to rostrum, seven annules in 10 µm on the region of ventral bend, and four annules in 10 µm on posterior half of the body. Cuticle of a male composed of 157 annules. Annules of the pharyngeal region ornamented with one row of tiny oval vacuoles. Very tiny spines, visible distinctly only with SEM, located on the dorsal side of the body and directed backwards (Fig. 10 E). Spines located predominantly on the anterior body, from body bend to anal region; spines on dorsal side of posterior half of the body 2 – 2.5 times longer than those on ventral side (3 Μ m and 1 Μ m, respectively). Labial region composed of six lips usually inverted into the head in fixed specimens (Fig. 10 A). Six inner labial papillae located on outer side of the lips. Six outer labial as short setae on anterior part of the rostrum. Four cephalic setae (3.6 – 8.0 Μ m long in males, 3.7 – 8.3 Μ m long in females) situated at level of the amphideal fovea. Amphideal foveas spirally coiled in 1.5 turns (Fig. 10 B); their width 0.4 – 1.7 Μ m in males and 0.8 – 1.4 Μ m in females; the amphideal foveas shifted a bit to dorso-lateral position. No evident difference between foveas of males and females. Thirty to 50 thin hair-like somatic setae on either body side. Somatic setae mostly 9 – 11 Μ m in length, but quite a few single setae may be longer (17 – 19 Μ m). The ambulatory setae thick, slightly bent in the middle, their tips hooked. Ambulatory setae arranged in four rows on mid-body; all about equal in size or posterior setae slightly shorter. All ambulatory setae located anterior to the anus. Latero-ventral rows a bit longer (their ends located more posteriorly) than subventral rows. Stoma small and unarmed. Pharynx short, muscular; terminal bulb strongly developed, oval to rounded, with thickened internal cuticle. Male reproductive system consists of an anterior outstretched testis extending to the ventral bend. Spicules strongly curved, thick; proximal ends distinctly knobbed, distal ends pointed. Gubernaculum a small bar at distal end of spicules. Small and sometimes nearly imperceptible copulatory thorns present as local ventral projections of cuticular annules just posterior to the rows of ambulatory setae. Position of the thorns varies from 5 – 7 th to 10 – 13 th, more often from 6 th – 10 th and from 7 th – 11 th. Four copulatory thorns (Fig. 9, 10 C). Female reproductive system didelphic-amphidelphic; ovaries antidromously reflexed and located ventrally or left ventro-laterally of the intestine. Vulva not bulging, sometimes indistinct, situated in the middle of the ambulatory setae rows (five latero-ventral and seven subventral setae anterior and five latero-ventral and four subventral setae posterior to vulva on either body side). Tail short, conical, with up to 10 – 11 somatic setae. Caudal glands terminating with three separate outlets on tail tip.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF9EFFD6FF30FE6DFAE35D9D.taxon	diagnosis	Diagnosis. Epsilonema. Body length of adults 276 – 454 Μ m. Body curved epsilon-like, with narrowest region between pharynx and anterior gonad levels, just anterior to the ventral bend. Body cuticle composed of nearly 150 – 160 annules. Annules of the pharyngeal region ornamented with one row of tiny oval vacuoles. Very minute spines discerned only with SEM, located on annules predominantly on mid- to posterior part of body. Amphideal fovea coiled in ~ 1.5 turns, 0.4 – 1.7 Μ m wide, situated at base of the conical rostrum. Ambulatory setae arranged in four rows between ventral bend and anal opening; eight to 16 setae in latero-ventral rows and nine to 13 in subventral rows. Spicules 26 – 51 Μ m (arch). About four copulatory thorns present on ventral body at or just posterior to posterior end of rows of ambulatory setae.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
03F17E4CFF9EFFD6FF30FE6DFAE35D9D.taxon	discussion	Discussion. The first species of Epsilonema was found at Salerno (Italy, Tyrrhenian Sea) on littoral algae and described by Metschnikoff (1867) under the name Rhabdogaster cygnoides. The description was based on a single female and lacks significant details used nowadays for morphological discrimination of species. However, the species described by Metschnikoff fits the genus Epsilonema well in its current understanding (Gourbault & Decraemer 1996; Tchesunov 2014). In fact, the original diagnosis of Epsilonema cygnoides by Metschnikoff (1867) consists of generic but not species characters; hence this species would not be recognized today if found away from its type locality. The species was recorded later in papers on collections from the North Sea, Canary Islands and Mediterranean without illustrations or remarks on morphology. Schepotieff (1908) found Rhabdogaster cygnoides abundant on hard substrates in Bergen (Norway), Neapel, Rovigno and Brindisi (Mediterranean), from shallow to depth 250 m, and gave a description in more detail and even with cross-sections. Unfortunately, Schepotieff did not indicate where specifically the figured and described specimens had been sampled. Since the vulva may be situated in different females within or posterior to the row of ambulatory setae as depicted on Figs 3 and 6 and noted in the text, it is possible the author dealt with a mixture of species. Having the pharynx swollen and forming two distinct consecutive bulbs anterior to the nerve ring is a very unlikely feature, not known among epsilonematid nematodes. Steiner (1916) described and depicted a female Rhabdogaster cygnoides from the Barents Sea. Our White Sea female specimens fit this description well, although it lacks some fine but important characters currently used for species diagnostics. Later, Steiner (1931) considered the Barents Sea specimen to belong to a separate species. Chitwood (1935) named the Barents Sea species “ Epsilonema steineri ” but gave no grounds for doing so. Later, the species Epsilonema steineri was transferred to the genus Epsilonematina Johnston, 1938 (see Gerlach & Riemann 1973). However, Lorenzen (1973) found no significant differences between descriptions of Metschnikoff and Steiner, and therefore accepted steineri as a junior synonym of cygnoides; he also rejected validity of Epsilonematina. Both synonymies were accepted in the review of Epsilonematidae by Gourbault & Decraemer (1996). Here, we identify the White Sea species as Epsilonema steineri Chitwood 1935 based on two considerations: (1) no differences between our specimens and the description of Steiner (1916); (2) the White Sea locality is close to that of the Barents Sea. This is a preliminary decision; it may be verified or falsified by morphological re-descriptions and molecular genetic studies of Epsilonema cygnoides and E. steineri from their type localities. We also qualify Epsilonema cygnoides (Metschnikoff, 1867) as species inquirenda until it can be thoroughly re-described based on specimens from the type locality, i. e. the vicinity of Salerno, Tyrrhenian Sea.	en	Fedyaeva, Maria A., Neretina, Tatjana V., Konovalova, Olga P., Tchesunov, Alexei V. (2016): Two known and one new species of Draconematidae and Epsilonematidae (Nematoda, Desmodorida) from the White Sea, North Russia. Zootaxa 4121 (4): 383-411, DOI: 10.11646/zootaxa.4121.4.2
