taxonID	type	description	language	source
704ECD36FFF42176FDE1EA8ACECEDDA9.taxon	discussion	Remarks. This genus was established by Erséus (1984) with D. tener Erséus, 1984 from Hong Kong as type species, and then expanded to accommodate D. diverticulatus Erséus, 1985 from Saudi Arabia (Erséus, 1985). Later, a third species, D. puertoricensis Erséus and Milligan, 1988, was added from Puerto Rico (Erséus and Milligan, 1988). In this paper, we describe eight new species belonging to this genus, but some of them do not conform completely with the previous diagnosis, which thus needs to be revised, and this will be done in a more comprehensive study of the subfamily Limnodriloidinae elsewhere. As a rule, the members of Doliodrilus are characterized by: (1) a modified, enlarged, tract of oesophagus in IX (sometimes involving also a part of VIII) bearing a reticulate blood plexus (see Gustavsson and Erséus, 1999); (2) distinct prostatic pads, each restricted to a limited region of the atrial ampulla (see Erséus, 1982); (3) weakly granulated atrial ducts (see Erséus, 1982), generally provided with blind sacs or ectal dilatations, and terminating in simple male pores; (4) large, deeply staining, nucleus-like bodies in the prostate glands of some species, their true nature being unknown; and (5) vestibules at the ectal orifices of the spermathecal ducts.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFF32173FDEAEE97CE43DA2C.taxon	description	Doliodrilus tener Erséus, 1984: 159 – 160, figure 15; Erséus, 1990 a (partim): 287 – 288, figure 11 A, B, E – G, I, J; Erséus et al., 1990: 113, figure 2 K; Erséus and Hsieh, 1997: 100 – 101. New material. IHB HANA 2000003 b – e, HANA 2000017 e, HANA 2000022 a – e, HANA 2000029 c – f, 14 specimens: four from SY 00 - 2 A, one from SY 00 - 9 C, five from Station HU 00 - 14 A, four from HU 00 - 19 A. SMNH Main Coll. 43665 – 43677, 13 specimens: three from SY 00 - 2 A, seven from HU 00 - 14 A, three from HU 00 - 19 A. Brief description of new material. Six complete specimens 5.1 – 9.8 mm long, 28 – 45 segments. Diameter at XI about 0.4 mm. Prostomium usually conical. Clitellum extending over XI – XII. Chaetae 50 – 75 m m long, about 2.5 m m thick, with upper teeth 1 – 1.5 times as long as, and thinner than or as thick as, lower; two to five per bundle anteriorly, one to three per bundle in post-clitellar segments. Chloragogen cells from VI onwards. Oesophagus in IX barrel-shaped, thick-walled and granulated, with or without chloragogen cells; semi-embedded blood plexus permeating dorsal region, with regular transverse vessels and less regular longitudinal ones. Vasa deferentia (figure 1 A: vd) about 135 m m long, 12 – 19 m m wide. Atria totally 200 – 220 m m long, 14 – 36 m m wide; ental end of atrial ampullae thin-walled and distinctly dilated; ventral projections on ampullae either (1) triangular (figure 1 A), each with small (only 10 – 17 m m long) prostatic pad (ppd) at bottom, and with numerous spindle-shaped nuclei (ncc) along both sides of pad (especially ental to pad), or (2) hemispherical (figure 1 B), with large (29 – 34 m m long) prostatic pad (ppd), and with dense, but smaller patches of slender nuclei (ncc) around pad. Dense cluster of nuclei also present in dorsal wall of ampulla opposite to prostatic pad; these nuclei slender and regularly arranged when ventral projection triangular (figure 1 A: nco), but oval and less regular when projection hemispherical (figure 1 B: nco). Prostate glands (figure 1 A, B: pr) usually medium to large, sometimes small, with small nuclei and large nucleus-like bodies, latter oblong to round, maximally 12 m m long, 11 m m wide. Atrial ducts (figure 1 A, B: ad) each with (1) posterior blind sac (bs), 25 – 50 m m long, 15 – 30 m m wide, and (2) efferent duct (ed), 25 – 35 m m long, 19 – 27 m m wide. Sperm sac in one to five segments within IX – XIII, when developed at all. Egg sac in one to three segments within XI – XIII, when developed. Spermathecal ducts 45 – 95 m m long, 24 – 44 m m wide, with ectal vestibules; ampullae 85 – 175 m m long, 30 – 95 m m wide, with sperm arranged in bundles or masses in lumina. Remarks. This species was originally described from Hong Kong (Erséus, 1984). In 1990, Erséus reported it from Hong Kong again, noting some morphological variation, but a form with unusually long upper teeth on the chaetae is now regarded as a separate taxon (see D. longidentatus sp. n. below). The other known distributional areas of D. tener are Qingdao (Erséus et al., 1990) and Taiwan (Erséus and Hsieh, 1997). The most prominent character of D. tener, not specifically noted in the previous descriptions, is the conspicuous thickening of the dorsal wall opposite to the prostatic pad in the atrium, and the clusters of nuclei in this wall and around the pad. We observed this character in all the material from Hainan, as well as in numerous old specimens from Hong Kong [treated by Erséus, 1984, 1990 a (partim)]. However, there are two different appearances of the ventral projections on the atria; they are either triangular (figure 1 A) or hemispherical (figure 1 B) (see above description). In the former state, the small prostatic pads seem to have discharged secretion into the atria, and the nuclei around the pads are widely distributed. In the latter state, the large pads appear to be full of secretion, and the nuclei are more restricted in distribution. The prostate glands were stated to be small in the Hong Kong material (Erséus, 1984, 1990 a), but a re-examination shows that the glands in the specimens from Hong Kong and Taiwan (Erséus and Hsieh, 1997), as well as in the new material, vary considerably, i. e. from small to large. Distribution and habitat. Known only from China [Hainan (new record), Hong Kong, Jiaozhou Bay (at Qingdao), Taiwan]. Brackish-water, intertidal and subtidal soft mud and muddy sand.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFF1217DFD03EF56CDB3DA4C.taxon	description	(figure 2)	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFF1217DFD03EF56CDB3DA4C.taxon	materials_examined	Holotype. SMNH Type Coll. 5457, whole-mounted specimen. Type locality. Japan, Honshu, Mie Prefecture, Gokasho Bay, brackish-water; 16 May 1990, coll. K. Ogawa. Paratypes. SMNH Type Coll. 5458 – 5460, three specimens from type locality. Other material. IHB HANA 2000009 al, one specimen from Hainan Island, Station SY 00 - 6. Etymology. The specific name bisaccus is Latin for ‘ with two sacs’, and refers to the bilobed atrial ampullae, a feature unique within the genus. Description of type material. Two complete specimens, holotype 9.7 mm with 43 segments, one paratype 8.4 mm with 41 segments. Diameter at XI 0.3 – 0.5 mm. Prostomium usually conical. Clitellum well developed over XI – XII. Chaetae bifid, with upper teeth more or less as long as, and thinner than, or sometimes as thick as, lower (figure 2 A). Chaetae 45 – 60 m m long, about 2.5 m m thick; (zero) one to two (three) per bundle anteriorly, zero to two per bundle in post-clitellar segments. Ventral chaetae absent in XI. Male pores, paired in line with ventral chaetae in posterior part of XI (figure 2 B). Spermathecal pores paired in line with ventral chaetae in anterior part of X. Pharyngeal glands well developed in IV – V. Chloragogen cells from VI onwards. Oesophagus in IX barrel-shaped, thick-walled and granulated, without chloragogen cells; semi-embedded blood plexus permeating entire region, with regular transverse vessels and less regular longitudinal ones. Male genitalia (figure 2 C, D) paired. Vas deferens (figure 2 C, D: vd) short and wide, about 70 m m long, 19 – 22 m m wide, entering atrium apically. Ental part of atrial ampulla bilobed, thin-walled and dilated; lobes separated by constriction. First ‘ lobe’ of ampulla (figure 2 C, D: at 1) conical or oval, 35 – 65 m m long, maximally 39 – 53 m m wide. Second ‘ lobe’ oval (at 2), 35 – 50 m m long, maximally 39 – 44 m m wide. Ectal part of atrial ampulla more duct-like, thick-walled, with numerous slender nuclei close to (figure 2 C, D: ncc) and opposite to (nco) prostatic pad. This part 150 – 155 m m long, 16 – 48 m m wide. Prostatic pad (figure 2 C, D: ppd) round, 46 - 48 m m long, ventrally attached to middle of duct-like part of atrial ampulla (aa), bulging out from atrium. Prostate gland (figure 2 C, D: pr) large, with small nuclei and large nucleus-like bodies, latter oblong or round, maximally 16 m m long, 15 m m wide. Atrial duct (figure 2 C, D: ad) with (1) posterior blind sac (bs), 25 – 50 m m long, 15 – 48 m m wide, and (2) efferent duct (ed), 45 – 55 m m long, 31 – 48 m m wide, opening directly to exterior through simple pore. Sperm sac in IX – XII, or XI – XII. Egg sac in XII – XIII or absent. Spermathecae (figure 2 B) large; ducts 75 – 105 m m long, 36 – 48 m m wide, with ectal vestibules; ampullae oblong, thin-walled, 145 – 195 m m long, 50 – 75 m m wide, with sperm masses in lumina. Brief description of specimen from Hainan. Specimen complete, 5 mm long, 39 segments. Chaetae 45 – 55 m m long, about 2.5 m m thick, bifid, with equal teeth; one to two (three) per bundle anteriorly, one to two per bundle in post-clitellar segments. Male pores posterior to middle of XI. Male ducts somewhat twisted and difficult to make out. Spermathecae with oblong ampullae, but without sperm; specimen appears pre-copulatory. Remarks. This species is easily distinguished from all its congeners by its bilobed atrial ampullae, and low number of chaetae; latter usually no more than two per bundle or even absent. The atria have dorsal thickenings and clusters of slender nuclei around the prostatic pads, as well as blind sacs, suggesting a close relationship to D. tener. In the new species, however, the vasa deferentia are shorter than those of the latter, and the prostatic pads are situated at mid-point of the atrium, as opposed to the more ental location in D. tener. Although not all its features were clearly seen, the specimen from Hainan has fewer chaetae than D. tener, and appears to have blind sacs and clusters of slender nuclei in the atria. Therefore, it is identified as D. bisaccus, at least for the time being. Distribution and habitat. Japan and southern China. Brackish-water, muddy sands.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFF1217DFD03EF56CDB3DA4C.taxon	etymology	Etymology. The specific name bisaccus is Latin for ‘ with two sacs’, and refers to the bilobed atrial ampullae, a feature unique within the genus.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFF1217DFD03EF56CDB3DA4C.taxon	description	Description of type material. Two complete specimens, holotype 9.7 mm with 43 segments, one paratype 8.4 mm with 41 segments. Diameter at XI 0.3 – 0.5 mm. Prostomium usually conical. Clitellum well developed over XI – XII. Chaetae bifid, with upper teeth more or less as long as, and thinner than, or sometimes as thick as, lower (figure 2 A). Chaetae 45 – 60 m m long, about 2.5 m m thick; (zero) one to two (three) per bundle anteriorly, zero to two per bundle in post-clitellar segments. Ventral chaetae absent in XI. Male pores, paired in line with ventral chaetae in posterior part of XI (figure 2 B). Spermathecal pores paired in line with ventral chaetae in anterior part of X. Pharyngeal glands well developed in IV – V. Chloragogen cells from VI onwards. Oesophagus in IX barrel-shaped, thick-walled and granulated, without chloragogen cells; semi-embedded blood plexus permeating entire region, with regular transverse vessels and less regular longitudinal ones. Male genitalia (figure 2 C, D) paired. Vas deferens (figure 2 C, D: vd) short and wide, about 70 m m long, 19 – 22 m m wide, entering atrium apically. Ental part of atrial ampulla bilobed, thin-walled and dilated; lobes separated by constriction. First ‘ lobe’ of ampulla (figure 2 C, D: at 1) conical or oval, 35 – 65 m m long, maximally 39 – 53 m m wide. Second ‘ lobe’ oval (at 2), 35 – 50 m m long, maximally 39 – 44 m m wide. Ectal part of atrial ampulla more duct-like, thick-walled, with numerous slender nuclei close to (figure 2 C, D: ncc) and opposite to (nco) prostatic pad. This part 150 – 155 m m long, 16 – 48 m m wide. Prostatic pad (figure 2 C, D: ppd) round, 46 - 48 m m long, ventrally attached to middle of duct-like part of atrial ampulla (aa), bulging out from atrium. Prostate gland (figure 2 C, D: pr) large, with small nuclei and large nucleus-like bodies, latter oblong or round, maximally 16 m m long, 15 m m wide. Atrial duct (figure 2 C, D: ad) with (1) posterior blind sac (bs), 25 – 50 m m long, 15 – 48 m m wide, and (2) efferent duct (ed), 45 – 55 m m long, 31 – 48 m m wide, opening directly to exterior through simple pore. Sperm sac in IX – XII, or XI – XII. Egg sac in XII – XIII or absent. Spermathecae (figure 2 B) large; ducts 75 – 105 m m long, 36 – 48 m m wide, with ectal vestibules; ampullae oblong, thin-walled, 145 – 195 m m long, 50 – 75 m m wide, with sperm masses in lumina. Brief description of specimen from Hainan. Specimen complete, 5 mm long, 39 segments. Chaetae 45 – 55 m m long, about 2.5 m m thick, bifid, with equal teeth; one to two (three) per bundle anteriorly, one to two per bundle in post-clitellar segments. Male pores posterior to middle of XI. Male ducts somewhat twisted and difficult to make out. Spermathecae with oblong ampullae, but without sperm; specimen appears pre-copulatory.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFF1217DFD03EF56CDB3DA4C.taxon	discussion	Remarks. This species is easily distinguished from all its congeners by its bilobed atrial ampullae, and low number of chaetae; latter usually no more than two per bundle or even absent. The atria have dorsal thickenings and clusters of slender nuclei around the prostatic pads, as well as blind sacs, suggesting a close relationship to D. tener. In the new species, however, the vasa deferentia are shorter than those of the latter, and the prostatic pads are situated at mid-point of the atrium, as opposed to the more ental location in D. tener. Although not all its features were clearly seen, the specimen from Hainan has fewer chaetae than D. tener, and appears to have blind sacs and clusters of slender nuclei in the atria. Therefore, it is identified as D. bisaccus, at least for the time being. Distribution and habitat. Japan and southern China. Brackish-water, muddy sands.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFF1217DFD03EF56CDB3DA4C.taxon	distribution	Distribution and habitat. Japan and southern China. Brackish-water, muddy sands.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFFF217FFDEFEF44CD94D851.taxon	description	Doliodrilus tener Erséus (partim); Erséus, 1990 a: 287 – 288, figure 11 C, D, H, K; Gustavsson and Erséus, 1999: 470 – 471, figure 1 d – f.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFFF217FFDEFEF44CD94D851.taxon	materials_examined	Holotype. SMNH Type. Coll. 5461, whole-mounted specimen. Type locality. China, Hong Kong, mangroves at Mai Po, edge of dredged channel, mid-intertidal mud (Station HK 86 - 26 = ‘ Station 70 ’ in Erséus, 1990 a); 9 April 1986, coll. C. Erséus. Paratypes. SMNH Type. Coll. 5462 – 5466, five specimens from type locality. SMNH Type Coll. 5467 – 5468, two (sectioned) specimens from type locality. SMNH Type Coll. 5469 – 5470, two from Hong Kong, Deep Bay, mudflat just off mangroves at Mai Po marshes (Station HK 86 - 25 = ‘ Station 69 ’ in Erséus, 1990 a); 9 April 1986, coll. C. Erséus. SMNH Type Coll. 5471, one specimen from Hong Kong, Deep Bay, Tsim Bei Sui, intertidal mudflat (Station HK 86 - 31 = ‘ Station 76 ’ in Erséus, 1990 a); 10 April 1986, coll. C. Erséus. Other material. SMNH Main Coll. 43678 – 43679, two specimens from Hong Kong, Deep Bay, mangroves at Mai Po marshes, intertidal mud; 22 April 1989, coll. A. Mackie and G. Oliver. IHB HANA 2000023 a, one specimen from Hainan Island, Station HU 00 - 14 B. Etymology. The specific name longidentatus is Latin for ‘ with long teeth’, and refers to the long upper teeth of the chaetae. Description. No complete specimen in material from Hong Kong. Hainan specimen 9.3 mm long, about 50 segments. Diameter at XI 0.4 – 0.6 mm. Prostomium conical. Clitellum well developed over XI – XII. Chaetae bifid, with upper teeth 2 – 2.5 times as long as, and as thick as, lower (figure 3 A). Chaetae 70 – 85 m m long, about 3 m m thick; (two) three to four (five) per bundle anteriorly, two (three) per bundle in post-clitellar segments. Ventral chaetae absent in XI. Male pores paired, in line with ventral chaetae in posterior part of XI (figure 3 B). Spermathecal pores paired, in line with ventral chaetae in anterior part of X. Pharyngeal glands well developed in IV – V. Chloragogen cells from VI onwards. Oesophagus in IX barrel-shaped, thick-walled and granulated, without or with few chloragogen cells; semi-embedded blood plexus permeating dorsal region, with regular transverse vessels and less regular longitudinal ones. Male genitalia (figure 3 C, D) paired. Vas deferens (figure 3 C, D: vd) 160 – 255 m m long, 19 – 22 m m wide, entering atrium apically. Atrium totally 190 – 340 m m long, 14 – 48 m m wide; ental part of ampulla thin-walled and dilated, ectal part tubular and with more nuclei (figure 3 C, D: aa), but without clusters of dense slender nuclei around prostatic pad; when atrium not stretched (figure 3 C), dorsal wall opposite to prostatic pad somewhat thicker than other parts of ampullar wall. Prostatic pad (figure 3 C, D: ppd) round, 17 – 24 m m long, bulging out from atrial ampulla, usually situated at middle or ectal to middle of atrium (figure 3 C), but slightly ental to middle of atrium when latter is stretched (figure 3 D). Prostate gland (figure 3 C, D: pr) medium-sized, with small nuclei and large nucleus-like bodies, latter oblong to round, maximally 14 m m long, 10 m m wide. Atrial duct (figure 3 C, D: ad) with (1) large posterior blind sac (bs), 95 – 120 m m long, 15 – 40 m m wide, and (2) short efferent duct (ed), about 35 m m long, 31 - 48 m m wide. Sperm sac in one to two segments within IX – XI, when developed at all. Egg sac in one to two segments within XI – XIII, when developed. Spermathecae (figure 3 B) variable in size; ducts about 50 m m long, 22 – 31 m m wide, with ectal vestibules; ampullae oblong, 95 – 205 m m long, 60 – 75 m m wide, with sperm masses in lumina. Remarks. This species was previously regarded as a form of D. tener (Erséus, 1990 a), but as the result of a more careful assessment of the male genital ducts, it is now recognized as a separate taxon. It is distinguished from D. tener by the distinctly longer upper teeth of its chaetae, the absence of clusters of slender nuclei in the atria, the more ectal location of the prostatic pads on the atria, and, generally, the larger size of external and internal structures. The long upper teeth on the chaetae are shared by D. ciliatus sp. n. (described below), but otherwise this feature discriminates D. longidentatus from all congeners. The specimen from Hainan was studied from a dorsal view, and its identification is mainly based upon the features of the chaetae and the absence of nuclei clusters. Distribution and habitat. Southern China. Usually intertidal in mangroves, clay and mud.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFFD217EFD0DED4DCECBDDA9.taxon	materials_examined	Holotype. IHB HANA 2000023 b, whole-mounted specimen. Type locality. China, northern Hainan, mangroves of Dong Zhai Harbour nature reserve (Station HU 00 - 14 B). Etymology. The specific name ciliatus is Latin for ‘ furnished with cilia’ and refers to the ciliated atria. Description. Specimen complete, 12.0 mm, 69 segments. Diameter at XI 0.5 mm. Prostomium conical. Clitellum extending over XI – 1 / 2 XII. Chaetae bifid, with upper teeth about twice as long as lower (figure 4 A). Chaetae 70 – 85 m m long, about 2.5 m m thick; two to five per bundle anteriorly, two to three per bundle in post-clitellar segments. Ventral chaetae absent in XI. Male pores paired, in line with ventral chaetae in posterior part of XI (figure 4 B). Spermathecal pores paired, in line with ventral chaetae in X, at about one-third of segment from anterior septum (figure 4 B). Pharyngeal glands well developed in IV – V. Chloragogen cells from VI onwards. Anterior third of oesophagus in IX unmodified, with wall only 25 – 35 m m thick. Posterior two-thirds of oesophagus in IX barrel-shaped, granulated, with wall up to 70 m m thick, but without chloragogen cells; semi-embedded blood plexus present, but inconspicuous, with regular transverse vessels and less regular longitudinal ones. Male genitalia (figure 4 B) paired. Vas deferens not clearly visible, estimated to be about as long as atrium, entering latter subapically (?). Atrium tubular, totally 230 m m long, 17 – 27 m m wide; ental part of atrial ampulla densely ciliated, thinwalled and somewhat dilated; ectal part of ampulla more thick-walled, and with wall containing more nuclei (figure 4 B: aa). Prostatic pad (ppd) oval, 31 m m long, ventrally situated, bulging out from middle of atrium. Prostate gland (pr) large, with small nuclei and large nucleus-like bodies, latter oblong, round or irregularly polygonal, maximally 14 m m long, 10 m m wide. Atrial duct (figure 4 B: ad) with (1) posterior blind sac (bs), about 30 m m long, 10 – 15 m m wide, and (2) short efferent duct (ed), about 30 m m long, 25 m m wide, opening directly to exterior through simple pore. Sperm sac extending through IX – X. Egg sac in XII – XIII. Spermathecae (figure 4 B: s) club-shaped; ducts 110 m m long, 27 – 34 m m wide, with small, but distinct ectal vestibules; ampullae oval, thin-walled, 120 m m long, up to 77 m m wide, with sperm bundles in lumina. Remarks. Initially, we hesitated to assign this species to the genus Doliodrilus, as the ental parts of its atria are ciliated, a character formerly considered to be an autapomorphy of Smithsonidrilus Brinkhurst, 1966 (Limnodriloidinae) (Erséus, 1990 b). However, D. ciliatus has a dilated oesophagus in segment IX, and although indistinct, there is an oesophageal blood plexus in this segment. This type of modification as well as the atrial blind sacs are characteristic of most Doliodrilus, and thus, it is reasonable to conclude that this species belongs to the latter genus. With regard to the chaetal morphology and male ducts, D. ciliatus appears to be closely related to D. longidentatus sp. n. described above, but it is easily differentiated from the latter and other congeners by its ciliated atria, and the short length of the modified part of the oesophagus in segment IX. Distribution and habitat. Known only from type locality, southern China. Lower intertidal in mangroves, clay and mud.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFFA217AFD05ED5FCF7BD92D.taxon	materials_examined	Holotype. IHB HANA 2000017 b, whole-mounted specimen. Type locality. China, southern Hainan, lower end of estuary SE of Teng Qiao Town (Station SY 00 - 9 C). Paratype. IHB HANA 2000017 c – d, two specimens from type locality. SMNH Type Coll. 5472 – 5474, three specimens from type locality. Etymology. The specific name ‘ adiacens ’ is Latin for ‘ adjacent’, and alludes to the position of the spermathecal pores, which are located immediately behind the anterior septum of segment X. Description. Two complete specimens, holotype 4.6 mm with 43 segments, one paratype 7.0 mm with 53 segments. Diameter at XI 0.3 – 0.4 mm. Prostomium blunt. Clitellum well developed over XI – XII. Chaetae bifid, with upper teeth variable in length (ranging from longer to shorter than lower teeth), and thinner than, or sometimes as thick as, lower (figure 6 A). Chaetae 40 – 60 m m long, about 2.5 m m thick; (one) two to four (five) per bundle anteriorly, (one) two to three per bundle in post-clitellar segments. Ventral chaetae absent in XI. Male pores paired, in line with ventral chaetae in posterior part of XI (figure 6 C, D). Spermathecal pores paired in line with ventral chaetae, immediately behind septum 9 / 10 (figure 6 B). Pharyngeal glands in IV – V; those in V sometimes indistinct. Chloragogen cells from VI onwards. Oesophagus in IX barrel-shaped, thick-walled and granulated, with chloragogen cells; semi-embedded blood plexus permeating dorsal region, with regular transverse vessels and less regular longitudinal ones. Male genitalia (figure 6 C, D) paired. Vas deferens (figure 6 C, D: vd) 120 – 155 m m long, about 18 m m wide, entering atrium subapically. Atrium tubular, totally 150 – 180 m m long, 16 – 24 m m wide; ental ampulla dilated but not thin-walled; dorsal wall opposite prostatic pad thin, and clusters of slender nuclei around pad absent (figure 6 C, D: aa). Prostatic pad (ppd) small, oval to round, 16 – 24 m m long, situated at middle or ectal to middle of atrium. Prostate gland (pr) medium-sized, with oblong to round nuclei, latter maximally 8 m m long, 5 m m wide. Atrial duct (figure 6 C, D: ad) with (1) posterior blind sac (bs), varying in size mainly with regard to extent of evagination of male pore, 15 – 50 m m long, 10 – 20 m m wide, and (2) efferent duct (ed), also variable, 10 – 40 m m long, 12 – 17 m m wide. Spermathecal ducts (figure 6 B) about 30 m m long, about 23 m m wide, with ectal vestibules; ampullae cylindrical, 70 – 100 m m long, 25 – 35 m m wide, with more or less sigmoid spermatozeugmata (figure 6 B: sz) in lumina. Remarks. This species has two distinguishing characters. First, its spermathecal pores are adjacent to the anterior septum of segment X, whereas those of all the congeners are well separated from the septum. Second, in D. adiacens sp. n., the vasa deferentia enter the atria at a considerable distance from the apical ends of the latter, while the vasa join the atria apically in most of the congeners (vasa slightly subapical in D. brachyductus sp. n. and, probably, also in D. ciliatus sp. n.). With regard to the male ducts, it seems likely that D. adiacens is closely related to D. tener and D. longidentatus sp. n. In addition to the above-mentioned features, D. adiacens differs from D. tener by its lack of clusters of slender atrial nuclei and the more ectal location of its prostatic pads, and from D. longidentatus sp. n. by the shorter upper teeth of its chaetae, and the thicker walls of the ental part of the atria. Distribution and habitat. Known only from type locality, Hainan, China. Brackish-water, lower intertidal, muddy sand.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFF82164FDB9ECA3CFA5D98A.taxon	materials_examined	New material. IHB HANA 2000003 a, one specimen from SY 00 - 2 A. SMNH Main Coll. 43681, one specimen from HU 00 - 19 A. Brief description of new material. One complete specimen 3.5 mm long, about 30 segments. Diameter at XI 0.3 – 0.4 mm. Prostomium conical. Clitellum extending over XI – XII. Chaetae 50 – 55 m m long, about 2.5 m m thick, with upper teeth variable in length, ranging from longer to shorter than lower teeth (figure 7 A); (two) three to four (five) per bundle anteriorly, one to three per bundle in post-clitellar segments. Chloragogen cells from VI onwards. Unpaired ventral diverticulum in IX variable; in specimen from SY 00 - 2 A, diverticulum (figure 7 F: od) only about 85 m m long, 40 – 50 m m wide, covered with cell projections, and without reticulate blood plexus; in specimen from HU 00 - 19 A, diverticulum (figure 7 E: od) larger, about 200 m m long, 80 – 90 m m wide, with conspicuous, more or less regular, blood plexus; moreover, in latter specimen, although less distinct, plexus developed also on other parts of the gut in IX – XII. Vasa deferentia (figure 7 D: vd) about 100 m m long, 10 m m wide. Atria slender, totally 135 – 160 m m long, 7 – 22 m m wide; ental part not thin-walled, tapering off on to vasa. Prostatic pads (figure 7 D: ppd) somewhat triangular, about 24 m m long. Prostate gland (pr) medium-sized, with oblong or round nuclei, latter maximally 7 m m long and 6 m m wide. Atrial ducts (figure 7 D: ad) each with (1) posterior blind sac (bs), 20 – 25 m m long, 10 – 35 m m wide, and (2) efferent duct (ed), 15 – 25 m m long, 17 – 24 m m wide. Spermathecal ducts 30 – 35 m m long, 12 – 29 m m wide; ampullae 50 – 55 m m long, 10 – 35 m m wide (figure 7 B, C); only the specimen from HU 00 - 19 A post-copulatory, with a few scattered spermatozoa in lumina of ampullae (figure 7 B). Remarks. This species was originally described from Saudi Arabia, and subsequently reported also from Darwin Harbour (Erséus, 1997 b) and Montebello Islands (Erséus, 1997 c) in Australia. The new material conforms to the previous descriptions (Erséus, 1985, 1997 b, 1997 c) in most aspects, particularly, with regard to male ducts. The unpaired diverticulum was first described as ‘ dorsal’ (Erséus, 1985), but was later shown to be attached to the ventral side of the oesophagus and from there to run upwards along one lateral side of the segment (Erséus, 1997 c; Gustavsson and Erséus, 1999). The new material conforms with the latter description. However, the diverticulum is variable in size, a large one being over twice as long as a small one. Such a variation was confirmed also by re-examination of the specimens from Saudi Arabia (treated by Erséus, 1985) and Darwin Harbour (treated by Erséus, 1997 b), which all have similar body size. In the Saudi Arabia material, the diverticulum is 100 – 180 m m long, 40 – 70 m m wide, and in that from Darwin Harbour, it is about 250 m m long, 100 m m wide. Referring to the blood plexus, it is absent or present in the diverticulum of the new material, and when present it may even extend more broadly on to the gut. Gustavsson and Erséus (1999) noted the irregular blood plexus in the diverticulum of Darwin Harbour worms, but on re-examination of that material, we found it also to be present in other parts of the gut in segments IX – 1 / 3 X. In the Saudi Arabian form, we also observed the irregular blood plexus in the diverticulum. Hence, a blood plexus is generally present in the diverticulum in D. diverticulatus, but it is less regular than in other species. In the original description by Erséus (1985), the clitellum is stated to extend over XI – 1 / 2 XII, but a re-examination of his material showed that it actually reaches the end of XII in some specimens. The new material falls within this variation. Distribution and habitat. Southern China (new record), Western Australia and Northern Territory in Australia, and Saudi Arabia. Brackish-water to marine, intertidal and subtidal in mangroves, sand and mud.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFE62166FDF0ED3FCE76DF93.taxon	materials_examined	Holotype. IHB HANA 2000018 a, whole-mounted specimen. Type locality. China, southern Hainan, brackish-water pond SE of Teng Qiao Town (Station SY 00 - 10). Paratypes. IHB HANA 2000009 a – d, HANA 2000017 a, five specimens: four from SY 00 - 6, one from SY 00 - 9 C. SMNH Type Coll. 5475 – 5479, five specimens: one from type locality, four from SY 00 - 6. Other material. IHB HANA 2000009 e – h, four specimens from SY 00 - 6. SMNH Main Coll. 43682 – 43685, four specimens from SY 00 - 6. SMNH Main Coll. 43686 – 43695, 10 specimens from Fiji, Viti Levu, Lauthala Bay (E of Suva), Rewa River Delta at N end of Lauthala Island, mangrove swamp, mud, intertidal, oligohaline brackish-water; 3 December 1982, coll. C. Erséus (Station FI 82 - 16). Etymology. The specific name fibrisaccus, Latin meaning ‘ with fibrous sac’, refers to the muscular ectal part of the male duct. Description of material from Hainan (figure 8 A – C). Six complete specimens 3.5 – 9.7 mm long (holotype: 6.5 mm), 23 – 57 segments (holotype: 33). Diameter at XI 0.3 – 0.4 mm. Prostomium more or less conical. Clitellum more or less developed over XI – XII. Chaetae (figure 8 A) bifid, with upper teeth thinner, and shorter than, or as long as, lower. Chaetae 45 – 60 m m long, about 2.5 m m thick, (one) two to four (five) per bundle anteriorly, (one) two (three) per bundle in post-clitellar segments. Ventral chaetae absent in XI. Male pores paired, in line with ventral chaetae in posterior part of XI (figure 8 C). Spermathecal pores paired, in line with ventral chaetae in anterior part of X (figure 8 B). Pharyngeal glands in IV – V; those in V sometimes indistinct or absent. Chloragogen cells from VI onwards. Oesophagus in IX barrel-shaped, thickwalled and granulated, usually with few chloragogen cells; semi-embedded blood plexus permeating entire region, with regular transverse vessels and less regular longitudinal ones. Male genitalia (figure 8 C) paired. Vas deferens (figure 8 C: vd) longer than atrium, 155 – 200 m m long, 4 – 7 m m wide, straight or irregularly coiled, entering atrium apically. Atrium tubular, totally 150 – 190 m m long; ental (shorter) part of ampulla (figure 8 C: aa) thin-walled and somewhat dilated, oval to round, about 25 m m wide; middle (longer) duct-like part of atrium 14 – 16 m m wide, with thicker inner epithelium. Prostatic pad (figure 8 C: ppd) oval to round, 35 – 60 m m long, ventrally attached to atrium, ental to middle of duct-like part. Prostate gland (pr) small, posteriorly situated, with oval to round nuclei, latter maximally 7 m m long and 5 m m wide. Ectal part of atrium sacciform (figure 8 C: ead), 70 – 80 m m long, maximally 40 – 65 m m wide, with 10 – 12 m m thick muscular layer. Sperm sac, when developed, extending through one of segments IX – XI. Egg sac, when developed, extending through one to two segments within XI – XIII. Spermathecae (figure 8 B) slender; ducts 45 – 80 m m long, 15 – 30 m m wide, with ectal vestibules; ampullae oval to round, thin-walled, 55 – 60 m m long, 20 – 45 m m wide, with scattered spermatozoa in lumina. Brief description of material from Fiji (figure 8 D, E). Four complete specimens 3.0 – 8.5 mm long, 17 – 52 segments. Diameter at XI 0.2 – 0.3 mm. Chaetae 45 – 55 m m long, about 2.5 m m thick, with upper teeth thinner and shorter than lower; (two) three to four per bundle anteriorly, usually two per bundle in post-clitellar segments. Vasa deferentia (figure 8 E: vd) 160 – 195 m m long, about 12 m m wide. Atria totally 160 – 200 m m long, with ental part of ampullae (figure 8 E: aa) 19 – 22 m m wide, middle duct-like part 15 – 17 m m wide. Prostatic pads (figure 8 E: ppd) about 30 m m long. Prostate glands (pr) broadly attached to pads, with nuclei maximally 7 m m long, about 5 m m wide. Ectal sacciform parts of atria (figure 8 E: ead) 75 – 100 m m long, maximally 36 – 48 m m wide, with 3 – 10 m m thick muscular layer. Spermathecal ducts about 60 m m long, 24 – 27 m m wide; ampullae oval, 55 – 65 m m long, 25 – 30 m m wide, containing sperm masses (figure 8 D). Remarks. This taxon has a heavily muscular, dilated, ectal part in each male duct, which is not present in any other species of Doliodrilus. It is not conclusive whether this structure is a proper copulatory sac, i. e. a secondary ectodermal invagination associated with the male pore, or whether it is homologous to the ectal part of the atrial duct, but the latter hypothesis is implied in the description above. In several other species of Doliodrilus, such as D. tener and D. diverticulatus, the ectalmost part of the atrium is modified and includes a posterior blind sac. In most of our specimens of D. fibrisaccus, the irregularity in the outline of the muscular sac (i. e. with the posterior face of the sac bulging more than the anterior face; see figure 8 C, E: ead) appears to suggest homology with the ‘ blind sac’ of other species. The material from Fiji is similar to that from Hainan. However, in the Fijian worms, the vasa deferentia are thicker, and the ectal dilatations on the atria are somewhat longer and generally thinner, than the corresponding features in the Hainanese material. Distribution and habitat. Southern China and Fiji. Brackish-water, lower intertidal, muddy sand.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFE42160FDEFEB10CEBADA4C.taxon	materials_examined	Holotype. IHB HANA 200009 ak, whole-mounted specimen. Type locality. China, southern Hainan, brackish-water pond near Teng Hai (E of Sanya City) (Station SY 00 - 6). Etymology. The specific name brachyductus is Greek for ‘ with short duct’, and alludes to the short, simple male duct. Description. Holotype 6.7 mm long, 53 segments. Diameter at XI about 0.2 mm. Prostomium blunt. Clitellum inconspicuous. Chaetae bifid, with upper teeth as long as but much thinner than lower (figure 9 A). Chaetae 45 – 50 m m long, about 2.5 m m thick; two to three per bundle anteriorly, (one) two to three per bundle in postclitellar segments. Ventral chaetae absent in XI. Male pores paired, in line with ventral chaetae, posterior to middle of XI (figure 9 B). Spermathecal pores paired, in line with ventral chaetae, anterior to middle of X (figure 9 B). Pharyngeal glands in IV – V. Chloragogen cells from VI onwards. Oesophagus in IX barrel-shaped, thick-walled and granulated, with few chloragogen cells; semiembedded blood plexus permeating entire region, with regular transverse vessels and less regular longitudinal ones. Male genitalia (figure 9 B) paired. Vas deferens (figure 9 B: vd) longer than atrium, about 100 m m long, 5 m m wide, entering atrium slightly subapically. Atrium tubular or somewhat spindle-shaped, ental part (figure 9 B: aa) somewhat dilated but not thin-walled, ectal part (ead) distinctly dilated but opening to exterior through simple pore; atrium totally 70 – 80 m m long, 15 – 17 m m wide for most part, 25 – 30 m m wide at ectal dilatation. Prostatic pad (figure 9 B: ppd) oval to round, 22 – 24 m m long, ventrally attached to atrium, distinctly ental to middle of latter. Prostate gland (pr) small, with oval nuclei, latter maximally 5 m m long, 3 m m wide. Spermathecae (figure 9 B: s) small; ectal ducts short, indistinct; ampullae oval and thick-walled, 50 – 95 m m long, 25 – 45 m m wide, each with a few spermatozoa in lumina. Remarks. This new species resembles D. fibrisaccus sp. n. in certain aspects of the atria, i. e. the ectal parts are dilated, the ental parts are short, the prostatic pads are entally located, and the prostate glands are small. In D. brachyductus sp. n., however, the ectal dilatations of the atria have no distinct musculature, as opposed to the thick muscular layers in D. fibrisaccus. Moreover, the spermathecal ducts of D. brachyductus are indistinct, whereas those of D. fibrisaccus are about as long as the spermathecal ampullae (cf. figure 8 B, D). Distribution and habitat. Known only from type locality, southern China. Brackish-water, muddy sand.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFE22160FD06EF4FCEBADDA9.taxon	materials_examined	Holotype. IHB HANA 2000009 af, whole-mounted specimen. Type locality. China, southern Hainan, brackish-water pond near Teng Hai (E of Sanya City) (Station SY 00 - 6). Paratypes. IHB HANA 2000009 ag – aj, four specimens from type locality. SMNH Type Coll. 5480 – 5484, five specimens from type locality. Etymology. The specific name bidolium, Latin meaning ‘ two small barrels’, alludes to the modified oesophagus, which in VIII – IX is thick-walled, granulated, and bearing a reticulate blood plexus. Description. Two complete specimens, holotype 11.0 mm with 58 segments, one paratype 9.8 mm long, 50 segments. Diameter at XI about 0.5 mm. Prostomium blunt. Clitellum more or less developed over XI – XII. Chaetae (figure 10 A) bifid, with upper teeth thinner and shorter than, or as long as, lower. Chaetae 45 – 55 m m long, about 2.5 m m thick; (one) two to four per bundle anteriorly, one to three per bundle in post-clitellar segments. Ventral chaetae absent in XI. Male pores paired, in line with ventral chaetae in mid-XI (figure 10 D). Spermathecal pores paired in line with ventral chaetae in anterior part of X. Pharyngeal glands in IV – V. Chloragogen cells from VI onwards. Oesophagus in posterior two-thirds of VIII and whole of IX thick-walled and granulated, constricted at septum 8 / 9, without or with chloragogen cells; semi-embedded blood plexus permeating entire region, with regular transverse vessels and less regular longitudinal ones. Male genitalia (figure 10 D) paired. Vas deferens (figure 10 D: vd) short, 50 – 60 m m long, 7 – 10 m m wide, entering atrium apically. Atrium (figure 10 D: a) slender and somewhat spindle-shaped, about 185 m m long, 12 – 27 m m wide; ental part tapering off on to vas but not thin-walled; ectal part slightly dilated and opening to exterior through simple pore. Prostatic pad (figure 10 D: ppd) round, about 30 m m long, ectally situated, i. e. about one-third up atrium from male pore; pad bulging out from atrium. Prostate gland (pr) medium-sized, with small nuclei and large nucleuslike bodies, latter oval to round, maximally 10 m m long, 7 m m wide. Sperm sac inconspicuous. Egg sac in XI – XII or XI. Spermathecae (figure 10 B, C) small; ducts about 50 m m long, 17 – 27 m m wide, with ectal vestibules; ampullae oval and thickwalled, about 35 m m long, 30 – 40 m m wide, with few scattered sperm (figure 10 B) or distinct sperm bundles (figure 10 C) in lumina. Remarks. In this new species, the modification of the oesophagus extends forward into, and through a large part of, VIII, which is a feature unique within the subfamily Limnodriloidinae. With regard to the simple atria and the position of the male pores, D. bidolium is similar to D. puertoricensis, but it differs from the latter by its shorter vasa deferentia and its more ectal position of the prostatic pads in the atria. Distribution and habitat. Known only from type locality, southern China. Brackish-water, muddy sand.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFE1216DFD07EB82CEBADEF2.taxon	materials_examined	Holotype. IHB HANA 2000009 i, whole-mounted specimen Type locality. China, southern Hainan, brackish-water pond near Teng Hai (E of Sanya City) (Station SY 00 - 6). Paratypes. IHB HANA 2000009 j – n, five specimens from type locality. SMNH Type Coll. 5485 – 5489, five specimens from type locality. Other material. IHB HANA 2000009 o – ae, 17 specimens from type locality. SMNH Main Coll. 43696 – 43712, 17 specimens from type locality. Etymology. This species is known only from China so far, and its name is Latin for ‘ of China’. Description. Seven complete specimens 8.2 – 12.0 mm (holotype: 10.6 mm), 53 – 66 segments (holotype: 58). Diameter at XI 0.4 – 0.6 mm. Prostomium blunt or conical. Clitellum extending over XI – XII. Chaetae (figure 11 A) bifid, with upper teeth usually thinner and shorter than lower, teeth sometimes equal in length. Chaetae 50 – 75 m m long, about 2.5 m m thick; two to four per bundle anteriorly, one to three per bundle in post-clitellar segments. Ventral chaetae absent in XI. Male pores paired, in line with ventral chaetae in posterior part of XI (figure 11 E). Spermathecal pores paired, in line with ventral chaetae in anterior part of X. Pharyngeal glands in IV – V, those in V sometimes indistinct or absent. Chloragogen cells from VI onwards. Oesophagus in IX barrel-shaped, thick-walled and granulated, with chloragogen cells absent, scarce or (sometimes) abundant; semi-embedded blood plexus permeating entire region, with regular transverse vessels and less regular longitudinal ones. Male genitalia (figure 11 E) paired. Vas deferens (figure 11 E: vd) shorter than atrium, 80 – 100 m m long, about 16 m m wide, entering atrium apically. Atrium (figure 11 E: a) altogether somewhat spindle-shaped, 205 – 235 m m long, 31 – 43 m m wide, opening to exterior through simple pore. Ental end of atrium neither thinwalled nor dilated, somewhat tapering off on to vas. Prostatic pad (figure 11 E: ppd) round, 44 – 53 m m long, ventrally attached ental to middle of atrium; pad bulging out from atrium. Prostate gland (pr) large, with small nuclei and large nucleus-like bodies, latter oval to round, maximally 14 m m long and 12 m m wide. Ectal part of atrium simple, with neither blind sac nor dilatation (figure 11 E). Sperm sac large, extending through two to five segments in IX – XIII. Egg sac when developed, restricted to one segment within XII – XIII. Spermathecae (figure 11 B – D) large; ducts 40 – 80 m m long, 24 – 51 m m wide, with small ectal vestibules; ampullae oval and thinwalled, 175 – 195 m m long, 65 – 115 m m wide, sperm in lumina usually as dense, somewhat sea-horse-shaped spermatozeugmata (figure 11 B, C), sometimes in random masses (figure 11 D). Remarks. This new species is characteristic, as it usually has somewhat sea-horseshaped spermatozeugmata. Considering the simple male ducts, with rather short vasa deferentia, D. chinensis sp. n. shows similarities to, and is possibly closely related to, D. bidolium sp. n. However, in addition to the difference with regard to the oesophageal modifications (see Remarks for D. bidolium), the prostatic pads of D. chinensis are situated more entally on the atria, and the male pores are located posteriorly in segment XI, not in mid-XI as in D. bidolium. Distribution and habitat. Known only from type locality, southern China. Brackish-water, muddy sand.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFEF216FFE69EBF0CE16DA8D.taxon	materials_examined	New material. SMNH Main Coll. 43713 – 43714, two whole-mounted specimens from New Caledonia, Touhou, N of E end of point at Kombounou, 20 ° 46.6 ∞ S, 165 ° 14.4 ∞ E, mid-intertidal, pebbles, gravel, sand and black mud; 18 September 1993, coll. C. Erséus (Station NC 93 - 45). Brief description of new material. One complete specimen 7.7 mm long, 51 segments. Diameter at XI about 0.4 mm. Prostomium blunt. Clitellum extending over XI – XII. Chaetae 40 – 45 m m long, about 2.5 m m thick, with upper teeth variable in length but thinner than lower (figure 12 A); (one) two to four per bundle anteriorly, (one) two (three) per bundle in post-clitellar segments. Pharyngeal glands in IV – V. Chloragogen cells from VI onwards. Oesophagus in IX barrel-shaped, thick-walled and granulated; semi-embedded blood plexus permeating dorsal region. In the complete specimen, irregular blood plexus also present in posterior third of oesophagus in VIII. Vasa deferentia (figure 12 C: vd) about 5 m m wide, longer than atria. Atria (figure 12 C: a) tubular, 120 – 175 m m long, 17 – 19 m m wide; ental part of ampullae somewhat dilated but not thin-walled. Prostatic pads (figure 12 C: ppd) somewhat triangular, 34 – 44 m m long. Prostate gland (pr) small, with irregular to round nuclei, latter maximally 7 m m long, 6 m m wide. Sperm sac inconspicuous. Egg sac in XI. Spermathecae (figure 12 B) small; ducts 25 – 30 m m long, maximally 29 – 31 m m wide, with wide ectal vestibules; ampullae spherical, 35 m m long, maximally 35 – 40 m m wide, with sperm scattered or as bundles in lumina. Remarks. This species was originally described from Puerto Rico (Erséus and Milligan, 1988), and then reported from Belize (Erséus, 1990 b). The new material conforms well to the previous descriptions, except that its sperm are sometimes scattered in the spermathecae; they were originally stated to be in bundles only (Erséus and Milligan, 1988). In addition, we here supplement the description with details regarding the beginning of chloragogen cells, and the nature of the blood plexus associated with the oesophagus. In one of the specimens, the irregular blood plexus is present also in the posterior part of the oesophagus in segment VIII. A similar situation was observed in some specimens of Doliodrilus diverticulatus (see above). Thus, the presence or absence of an irregular oesophageal blood plexus around segment IX may be an intraspecific variation. Distribution and habitat. New Caledonia (new record), Belize, and Puerto Rico Intertidal and subtidal, mud and sandy mud; at least in Puerto Rico subject to fluctuating salinities.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFED216EFDAAEC11CFEBD96D.taxon	description	(figure 13)	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFED216EFDAAEC11CFEBD96D.taxon	materials_examined	New material. IHB HANA 2000017 f, one specimen from Station SY 00 - 9 C. Brief description of new material. Specimen incomplete, 5.1 mm long with 39 (anterior) segments. Prostomium blunt. Clitellum not developed. Somatic chaetae (figure 13 A) 45 – 50 m m long, 2.0 – 2.5 m m thick, with upper teeth shorter and thinner than lower; two to three per bundle anteriorly, (one) two per bundle in post-clitellar segments. All chaetae absent in XI. Spermathecal chaetae 55 m m long, about 3.0 m m thick, with ectal third grooved. Chloragogen cells from VI onwards. Vasa deferentia coiled, shorter than atria. Atria tubular; ampullae 130 m m long, 17 – 22 m m wide; atrial ducts 75 m m long, 10 m m wide, opening to exterior through complex bodies of tissue. Prostatic pads oval, about 24 m m long. Nuclei of prostatic glands oblong, maximally 7 m m long, 5 m m wide. Spermathecae (figure 13 B) small; ducts 30 m m long, 24 m m wide; ampullae oval, 50 m m long, 30 m m wide, with a few sperm bundles in lumina.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFED216EFDAAEC11CFEBD96D.taxon	discussion	Remarks. This post-copulatory specimen fits well the description of a single precopulatory worm reported from Hong Kong (Erséus, 1990 a), but in the Hainan worm, the upper teeth of the somatic chaetae are shorter than the corresponding lower teeth, while in the Hong Kong material, the upper and lower teeth were of about same length (Erséus, 1990 a: figure 16 A). Erséus (1990 a) listed five differences between the Hong Kong specimen and the type specimen from Saudi Arabia. He pointed out that the Chinese form may be separate, but more specimens are needed from both localities to enable a comprehensive comparison. Erséus (1990 a) also stated that the atrial ducts of his Hong Kong material were poorly granulated, whereas those of the holotype were heavily granulated (see also Erséus, 1985). However, a re-examination of the holotype shows that the granules of the atrial ducts almost cannot be observed; the heavy granulation was simply inferred from the irregularity of the inner epithelium. Thus, it now seems even more likely that the form from southern China indeed is conspecific with the original material of L. parahastatus.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFED216EFDAAEC11CFEBD96D.taxon	distribution	Distribution and habitat. Southern China (new record for Hainan) and Saudi Arabia. Shallow subtidal and lower intertidal, sandy mud.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
704ECD36FFEC216EFDBAEC18CDDBDEC3.taxon	materials_examined	New material. IHB HANA 2000012 a – b, two specimens from SY 00 - 8 A. SMNH Main Coll. 43715 – 43716, two specimens from SY 00 - 8 A. Brief description of new material. Two complete specimens 8.8 – 9.3 mm long, 69 – 70 segments. Diameter at XI 0.3 – 0.4 mm. Prostomium conical or blunt. Clitellum more or less developed in XI – XII. Chaetae 45 – 50 m m long, about 2.2 m m thick, with upper teeth shorter and much thinner than lower; (two) three to four per bundle anteriorly, (one) two per bundle in post-clitellar segments. Ventral chaetae absent in X – XI. Male pores in mid-XI (figure 14: mp). Chloragogen cells from VI – VII onwards. Vasa deferentia (figure 14: vd) about 200 m m long, 17 m m wide. Atrial ampullae (figure 14: aa) heavily muscular and contractile, about 90 m m long, maximally 73 m m wide when relaxed, but only about 75 m m long, maximally 60 – 65 m m wide when contracted. Atrial ducts (ad) 70 – 95 m m long, 19 – 44 m m wide. Prostatic pads (ppd) 36 m m long. Nuclei of prostatic glands round to oblong, maximally 7 m m long, 5 m m wide. Copulatory sacs (figure 14: cs) 70 – 75 m m long, 44 – 53 m m wide. Sperm sac extending through one to three segments within IX – XII. Egg sac absent, or extending through two to six segments in XII – XVII. Spermathecae absent. Remarks. This species was previously reported from Hong Kong (type locality) and Hawaii (Erséus, 1990 a). The new material fits well the original description, but the new specimens are longer than the paratype from Hawaii (about 9 mm, 70 segments versus 6 mm, 53 segments) (the holotype was not intact). The atrial ampullae of the present material are somewhat wider than those of previously studied worms (up to 73 m m wide versus maximally 60 m m wide). Distribution and habitat. Southern China (new record for Hainan) and Hawaii. Subtidal sands.	en	Wang, Hongzhu, Erséus, Christer (2004): New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean. Journal of Natural History 38 (3): 269-299, DOI: 10.1080/0022293021000028252, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293021000028252
