taxonID	type	description	language	source
03C5E0447145FFCAFED4E61AFEA8D95E.taxon	materials_examined	TYPE SPECIES. — Pseudexogone backstromi Augener, 1922, by original designation. POTENTIAL APOMORPHY BASED DEFINITION. — Bidentate curved notospines.	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E0447145FFCAFED4E61AFEA8D95E.taxon	description	SPECIES INCLUDED. — Pseudexogone backstromi Augener, 1922, P. dineti (Katzmann, Laubier & Ramos, 1974) n. comb., P. helmuti n. sp., P. imajimai n. sp. and P. williamsae n. sp.	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E0447145FFCAFED4E61AFEA8D95E.taxon	distribution	DISTRIBUTION. — Cosmopolitan. EMENDED DIAGNOSIS. — Synelminae with palps simple, each with a ventrolateral papilla. Three antennae. Eyes present or absent. Two pairs of tentacular cirri. Parapodia with bidentate curved notospines, neurochaetae include pectinate and denticulate capillaries and furcate chaetae.	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E0447145FFCAFED4E61AFEA8D95E.taxon	discussion	REMARKS Although the anterior end of P. backstromi resembles species of Exogone Ørsted, 1845, its general appearance is very similar to some pilargids that have been included in Synelmis Chamberlin, 1919 (Salazar-Vallejo 2003); besides, the differences in the structure of the alimentary canal, especially the presence of a proventricle in syllids, are so important that Augener had some doubts about its placement among syllids. Synelmis is usually defined by having biarticulate palps and straight notospines, but its perceived similarity to syllids is depicted by the generic placement that some species received in the past, e. g., Ancistrosyllis albini Langerhans, 1881 and A. rigida Fauvel, 1919. Synelmis is the type genus for Synelminae, which has been defined by having a smooth integument, body cylindrical, and straight or curved notospines (Salazar-Vallejo 2003). Pseudexogone belongs to this subfamily and differs from Synelmis especially by having simple palps, and bidentate sigmoid notospines. These two pilargid synelmin genera are apparently closely allied. Further, Pseudexogone is closely allied to Litocorsa Pearson, 1970; they share a thin transparent body and simple palps. However, they differ because Litocorsa has straight emergent notospines with tapering tips, instead of having notospines with bidentate tips. Further, Litocorsa has the potential autopomorphy of having neurospines (Darbyshire & Mackie 2003). In the original diagnosis, Augener (1922: 191) indicated that Pseudexogone was syllid-like, had a nematoid body with simple palps, simple hooks in median and posterior chaetigers, and an unarmed pharynx. After the description of P. backstromi, he tentatively placed the animal close to syllids (Augener 1922: 194). Augener (1922: 193) confused the position of the bidentate notospines, since he regarded them as ventral (neuropodial). This could be explained because of either the polychaete body was too transparent, or because he confused the typical morphology of the pygidium; i. e. anal cirri are generally ventral or ventrolateral, which is shown in his original drawings, but if the specimen was twisted, then there would be some confusion about which surface was dorsal or ventral in the posterior end. An important missing detail in the original description is the start of notospines; since this is a rather conservative useful feature (see below), this species could be separated by using additional materials or by employing other morphological features. Further delay in recognizing this genus as a member of the Pilargidae resulted because Pseudexogone was regarded as a syllid in two major reviews (Hartman 1959: 220; Fauchald 1977: 84). However, the same morphological features such as body pattern and structures (nematoid body, simple palps, bidentate emergent spines) were recognized in a pilargid by Katzmann et al. (1974), when they described Synelmis dineti (see below). As herein defined, Pseudexogone includes species living in subtidal depths and rarely from deeper waters (c. 1000 m depth). Besides the type species, it includes P. dineti n. comb., P. helmuti n. sp., P. imajimai n. sp., and P. williamsae n. sp.	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E0447142FFC9FEC8E718FC67DCE4.taxon	description	(Figs 1; 2)	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E0447142FFC9FEC8E718FC67DCE4.taxon	materials_examined	TYPE MATERIAL. — The type specimen of the type species was not deposited in Sweden, although it was collected during a Swedish expediton, nor in Hamburg, where Augener lived. Museum curators were unable to find it, therefore the type and only specimen is being regarded as lost. TYPE LOCALITY. — Másatierra (Robinson Crusoe) Island, Juan Fernández Archipelago, Chile. It was collected from a dead hydroid theca in a sample of calcareous algae, dredged in 30 - 45 m depth. MATERIAL EXAMINED. — Hawaii. Oahu, Off Barber’s Point, stn ZR 1, 21 ° 16 ’ 53.5 ” N, 158 ° 01 ’ 30.3 ” W, I. 2001, 63.7 m, 1 specimen (WRRC unnumb.). — Off Mamala, stn 26, 21 ° 17.35 ’ N, 157 ° 56 ’ 49.0 ” W, 32.9 m, VIII. 2001, 1 specimen (WRRC unnumb.). — Stn 27, 21 ° 17 ’ 38.2 ” N, 157 ° 55 ’ 31.8 ” W, 20.1 m, VIII. 2001, 2 specimens (WRRC unnumb.). — Off Mokapu, stn B 2 R 2 (no coordinates), 32.3 m, III. 1998, 2 specimens (WRRC unnumb.). — Stn B 2 R 3 (no coordinates), 32.3 m, III. 1998, 2 specimens (WRRC unnumb.). — Off Waianae, stn ZWR 6 (no coordinates), 36.6 m, X. 1996, 1 specimen (WRRC unnumb.). — Stn ZWR 2 (no coordinates), 33 m, V. 1998, 2 specimens (one WRRC unnumb., 1 gold-coated in ECOSUR). — Stn ZWR 1 (no coordinates), 36.3 m, V. 2001, 1 specimen (WRRC unnumb.).	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E0447142FFC9FEC8E718FC67DCE4.taxon	distribution	DISTRIBUTION. — Previously only known from the type locality in sublittoral rocky bottoms; the additional specimens were collected in Hawaii. They are regarded as belonging to P. backstromi, which implies a very wide distribution from the southeastern Pacific to the central north Pacific. The tiny size of P. backstromi and the presence of this species with sessile invertebrates, which may be widely distributed as foulers or as members of drifting communities, may explain this wide distribution.	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E0447142FFC9FEC8E718FC67DCE4.taxon	description	DESCRIPTION OF THE TYPE SPECIMEN (based on the original description and drawings) Body smooth, cylindrical, tapering towards anterior and posterior ends (Fig. 1 A); 9 mm long, 0.05 mm wide, c. 64 chaetigers. Prostomium subtriangular; palps simple, almost completely free from each other; one pair of large dorsal eyes; three antennae, the right lateral one placed ahead of the right eye. Two pairs of tentacular cirri, apparently the dorsal one longer than the ventral one (Fig. 1 B). Parapodia with dorsal and ventral cirri similar to each other. Median and posterior chaetigers with a single bidentate sigmoid notospine; each spine with large proximal tooth and smaller distal tooth (Fig. 1 C). Neurochaetae include finely denticulate capillaries (Fig. 1 D). Posterior end with one achaetous segment; pygidium with two ventrolateral anal cirri, each as long as pygidium plus achaetous segment (Fig. 1 E). Pharynx everted with margin smooth. DESCRIPTION OF NON- TYPE SPECIMENS Complete non-type specimens transparent, long, cylindrical, rarely yellowish, slightly wider anteriorly, tapering posteriorly (Fig. 2 A), 5.0 - 7.5 mm long, 0.12 - 0.30 mm wide, with 41 - 61 chaetigers. Prostomium subtriangular, about as long as wide, slightly narrower than peristomium. Three cirriform antennae of about the same size; lateral antennae located in the center of prostomium, median antenna placed on the posterior prostomial margin. Eyes dark brown, visible in all specimens. Palps anteriorly rounded, tapering, free from each other distally (Fig. 2 B); ventrolateral papillae cirriform, as long as antennae, placed half way along the palp length. Two pairs of cirriform tentacular cirri, equal-sized, most specimens with dorsal cirri longer, few with dorsal cirri slightly shorter, with a small median knob; ventral pair placed ventrally, appear smaller than dorsal one (Fig. 2 C). Ciliary bundles eroded. Parapodia uniramous in chaetigers 1 - 6, thereafter biramous. Parapodial cirri cirriform throughout body. Anterior parapodia with slightly emergent bidentate notospines, denticulate capillaries and furcates (Fig. 2 D). Dorsal cirri digitate, ventral cirri cirriform; dorsal ones slightly longer. Notopodia with large sigmoid bidentate spines starting on chaetiger 7 (in smaller specimens on chaetiger 5, rarely on chaetiger 8), continued to the last chaetiger. Neuropodia include furcates in anterior chaetigers, pectinates and denticu- late capillaries, mostly broken. In median and posterior chaetigers, about two pectinates and two denticulate capillaries per bundle. Furcates (Fig. 2 E) with unequal tines, longer tine with a short flange, smaller tine cylindrical. Median chaetigers (Fig. 2 F) without furcates; notospines emerge slightly. Notospines with larger subdistal tooth (Fig. 2 G). Posterior end tapering (Fig. 2 H), one achaetous segment visible in about half the specimens. Pygidium conical, rounded, with two lateral anal cirri (right cirrus lost). Anus terminal. Pharynx everted in few specimens, as long as the prostomium and palps, tubular, with smooth margin; ventral pharyngeal organ enlarged (Fig. 2 C). Brain lobes extended posteriorly to chaetiger 4. Oocytes present in larger specimens in chaetigers 15 - 40, measure 40 - 45 µm in diameter. VARIATION Notospines start on chaetigers 6 - 8 (5 in small specimens). Undamaged parapodia had one furcate, and two of each: pectinates and denticulate capillaries.	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E0447142FFC9FEC8E718FC67DCE4.taxon	discussion	REMARKS Pseudexogone backstromi resembles P. imajimai n. sp. and P. williamsae n. sp. by having well-defined eyes; they differ because of the type of furcates. In P. williamsae n. sp., they have a thicker, smaller tine while in the other two, they are thinner. The main differences between P. backstromi and P. imajimai n. sp. are on the relative shape of both prostomia and the larger tine of furcates. Thus, in P. backstromi the prostomium is about as long as wide, and the larger tine in furcates has a dorsal keel straight with a subdistal hump. On the contrary, in P. imajimai n. sp. the prostomium is markedly wider than long, and the larger tine in furcates has a dorsal keel curved with a subdistal notch. Furcates are very short and thus would be barely exposed to sediment abrasion or fractures, rendering their shape useful as a diagnostic feature. Because the specimens were collected in Hawaii, far away from the type locality, they should not be employed for establishing a neotype. Further, the specimens from Hawaii have faintly pigmented eyes, whereas in the type specimen they were very large. This difference may be due to sexual maturity since the type specimen was about 9 mm long, while these specimens were up to 7.5 mm long, or alternatively due to preservation and storing in ethanol. The start of bidentate notospines was not specified in the original description, but they start in chaetigers 6 - 8 in all Pseudexogone species, so that this feature is of very little use. A comparison between the original illustrations, the specimens and the SEM photos indicates a very close resemblance. Although the distribution is very wide, these pilargids may occupy a large geographic area with the same ecological conditions.	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E0447141FFC7FD29E2A3FC49DEDF.taxon	description	(Figs 3; 4)	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E0447141FFC7FD29E2A3FC49DEDF.taxon	materials_examined	TYPE MATERIAL. — Adriatic Sea. Holotype presumably lost. Croatia. Adriatic Sea, off Dubronik, sandy bottom, RV Jean Charcot, 42 ° 27 ’ N, 17 ° 01.8 ’ E, no date, 275 m, 3 paratypes (NHMW- 13078). TYPE LOCALITY. — Adriatic Sea, off Dubrovnik, Croatia, 42 ° 27 ’ N, 17 ° 01.8 ’ E, sandy bottom, 275 m. ADDITIONAL MATERIAL. — Northeastern Atlantic Ocean. Thalassa, stn Z- 414, 48 ° 05 ’ 00 ” N, 08 ° 20 ’ 08 ” W, off Brest, France, gravel, 650 m, 11 specimens (complete specimen 11 mm long, 0.15 mm wide, 52 chaetigers; notospines from chaetiger 6) (MNHN-A 488, As 418; one gold-coated in ECOSUR). DISTRIBUTION. — Northeastern Atlantic Ocean to the Adriatic Sea, in sandy bottoms in 275 - 650 m depth. REDESCRIPTION Paratypes (NHMW- 13078) three anterior fragments (one beheaded); larger anterior fragment with 38 chaetigers, notospines from chaetiger 7; smaller one with 16 chaetigers, notospines from chaetiger 6; head-less fragment with 11 chaetigers. Prostomium subtriangular (corrugated in SEM specimen, Fig. 4 A), about as long as wide, narrower than peristomium (Fig. 3 A). Three cirriform antennae of about the same size; lateral antennae placed in the middle of prostomium, over a low elevation, slightly ahead of median antenna, do not reach palp tips; median antenna on posterior prostomial margin. No eyes. Palps anteriorly rounded, distally separated, with one pair of ventrolateral papillae (Fig. 3 B, C), cirriform, as long as antennae (collapsed in SEM specimen). Two pairs of cirriform tentacular cirri, dorsal pair slightly longer (Fig. 4 B). Ciliary bundles eroded. Parapodia uniramous in chaetigers 1 - 6 (7), thereafter biramous. Parapodial cirri cirriform throughout body; dorsal cirri twice as long, and three times wider than ventral ones. Anterior parapodia (Fig. 4 C) with notospines slightly exposed. Chaetae include an emergent, brittle, sigmoid bidentate notospine (Fig. 3 D, E), first present in chaetigers 6 - 7, continued to posterior end; each notospine slightly curved (not sigmoid), with proximal tooth larger than distal one; neurochaetae 3 - 4 denticulate capillaries, some pectinates in a few anterior chaetigers, one smooth straight capillary (Fig. 3 F), and one furcate chaeta remaining in a few anterior chaetigers. Furcates (Fig. 4 D) with unequal tines, longer tine with a flaring curved blade not reaching the smaller, tapering tine. Posterior parapodia with notospines more exposed (Fig. 4 E), with 2 denticulate capillaries and one pectinate neurochaeta; dorsal cirri cirriform, longer than ventral cirri. Bidentate notospines from median chaetigers (Fig. 4 F) slightly exposed, with larger subdistal tooth and blunt distal tooth. Pygidium not seen in paratypes. The original description stated that it has two ventrolateral cirriform cirri (Fig. 3 G), about as long as the last achaetous segment. Brain with posterior lobes separated and passing the level of chaetal lobes in chaetiger 3. Pharynx 4.5 chaetigers long. VARIATION Specimens from northeastern Atlantic Ocean mostly anterior fragments; complete specimen was 9.5 mm long, with 51 chaetigers; others were eight anterior fragments, and two median fragments. Most had two brown eyespots external to the lateral antennae bases. Furcates were mostly broken but they seem to appear in chaetigers 1 - 2, and there are two furcates per bundle in chaetigers 1 - 3, then only one until chaetiger 5 or 6, thereafter they apparently disappear. One anterior fragment had its pharynx everted, it is distally smooth, barely surpassing palps. REMARKS Pseudexogone dineti n. comb. resembles P. helmuti n. sp. by lacking eyes. They differ in the relative devel- opment of the furcates blade; in P. dineti n. comb. the blade is curved, and straight in P. helmuti. Katzmann et al. (1974: 28) stated that the holotype was a complete specimen with 29 segments and that it had been formally deposited (and catalogued as NHMW- 13078). However, none of the specimens (labeled as paratypes in a small paper tag) were complete, so the holotype might be regarded as missing. On the other hand, Katzmann et al. (1974: 30) made an interesting discovery regarding the variation in the start of the notospines, since they found that in 13 out of 16 specimens, bidentate notospines started in chaetiger 6; in the other three specimens they started in chaetiger 7. Thus, it is a rather conservative feature. On the other hand, Darbyshire & Mackie (2003: 65) included S. dineti as a member of Litocorsa, despite the fact it has bidentate notospines and lacks neurospines. This inclusion prompted them to modify the generic definition. However, S. dineti belongs in Pseudexogone, not in Litocorsa, and the latter genus should be restricted as to include only those similar species provided with straight simple notospines, and neurospines.	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E044714FFFC2FD72E099FE20D9DC.taxon	description	(Fig. 5)	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E044714FFFC2FD72E099FE20D9DC.taxon	materials_examined	TYPE MATERIAL. — Southern Indian Ocean. Off Saint-Paul Island, Marion Dufresne, campagne MD 50 JASUS, stn 20 - DC 91, 38 ° 47 ’ 67 ” S, 77 ° 27 ’ 11 ” E, 17. VII. 1986, 975 m, very compacted fine sand, holotype (MNHN- 1482); paratypes (12 in MNHN, 6 in ECOSUR, including SEM specimen). TYPE LOCALITY. — Off Saint-Paul Island, southern Indian Ocean, in deep water.	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E044714FFFC2FD72E099FE20D9DC.taxon	etymology	ETYMOLOGY. — This species is named after Helmut Zibrowius, author of many important publications on serpulid polychaetes, and who participated in several cruises, including the one on which the specimens of this new species were collected.	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E044714FFFC2FD72E099FE20D9DC.taxon	distribution	DISTRIBUTION. — Only known from the type locality, off the Saint-Paul Island, southern Indian Ocean, in about 1000 m depth.	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E044714FFFC2FD72E099FE20D9DC.taxon	description	DESCRIPTION Holotype complete, transparent; body tapering posteriorly, 7.5 mm long, 0.25 mm wide, with 42 chaetigers. Prostomium subtriangular, about as long as wide, slightly narrower than peristomium (corrugated in SEM specimens). Three antennae, all cirriform of about the same size; laterals placed by the prostomial middle, median placed over the posterior prostomial margin. Eyes not visible. Palps tapering, separated distally, in SEM specimens distorted, free from each other (Fig. 5 A-C), each provided with a ventrolateral papilla (Fig. 5 B, C), as long as antennae, placed about the half of the palp length. Tentacular cirri cirriform, dorsal cirri slightly longer; ciliary bundles eroded (Fig. 5 B). Parapodia uniramous in chaetigers 1 - 6, thereafter biramous. Parapodial cirri cirriform throughout body. Anterior parapodia with two denticulate capil- laries, one pectinate, and one furcate neurochaetae (Fig. 5 D). Notopodia with large sigmoid bidentate spines starting in chaetiger 7, continued to last chaetiger. Neuropodia includes furcates in anterior chaetigers, pectinates and denticulate capillaries, most broken. Furcates with unequal tines, longer tine with a flaring blade not reaching the blunt digitate smaller tine. Median chaetigers (Fig. 5 E) with slightly emergent notospines, parapodial cirri digitate, dorsal cirri larger than ventral cirri. Chaetal lobe conical, with 2 denticulate capillaries and 1 or 2 pectinates. Bidentate curved notospines more exposed in posterior chaetigers (Fig. 5 F), each with rounded larger subdistal tooth, and a smaller, probably eroded, apical tooth. In median and posterior chaetigers, broken pectinates resemble furcates but they differ. Posterior end tapering. No achaetous segments. Pygidium conical, blunt, with two lateral anal cirri. Anus terminal. Pharynx not everted, as long as first 4 chaetigers in length. VARIATION The complete paratypes were 5.0 - 5.8 mm long, 0.15 - 0.25 mm wide, with 34 - 40 chaetigers. The start of notospines was in chaetiger 7. One with unbroken chaetae had two of each: furcates, pectinates and denticulate capillaries. There were no prepygidial achaetous segments. One paratype had its pharynx everted; it is made of two muscular rings with an apparently smooth margin.	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E044714FFFC2FD72E099FE20D9DC.taxon	discussion	REMARKS Pseudexogone helmuti n. sp. is the only described species of the genus living in almost 1000 m depth. It resembles P. dineti n. comb. by lacking eyes but they differ in the relative development of the blade of furcates; it is straight in P. helmuti n. sp. while it is curved in P. dineti n. comb.	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E044714AFFC1FEB6E79BFE69DCE5.taxon	description	(Figs 6; 7)	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E044714AFFC1FEB6E79BFE69DCE5.taxon	materials_examined	TYPE MATERIAL. — Northwestern Pacific Ocean. Japan, offTanega-shima, 30 ° 37.8 ’ N, 13 ° 054.2 ’ E, 45 m, VI. 1975, M. Imajima coll., holotype (NSMT- 85251). Guam. Off Tanguisson, stn WWRC T-NE-R 3, 13.5523 ° N, 144.8072 ° E, 43 m, 2001, 5 paratypes (USNM). — Stn WRRC T-NW-R 1, 13.5537 ° N, 144.8072 ° E, 50.3 m, 2001, 4 paratypes (MNHN). ADDITIONAL MATERIAL. — Guam. Off Tanguisson, stn WWRC T-NE-R 3, 13.5523 ° N, 144.8072 ° E, 43 m (no date available), 1 specimen (gold-coated, ECOSUR). — Stn WRRC T-NW-R 1, 13.5537 ° N, 144.8072 ° E, 50.3 m, 2001, 1 specimen (gold-coated, ECOSUR). TYPE LOCALITY. — Off Tanega-shima, Kyūshū, Japan, in 45 m. ETYMOLOGY. — The specific name is a modest homage to Dr. Minoru Imajima, in recognition of his very productive career in polychaete systematics, who has concentrated his efforts in Japanese fauna, and especially because of his publication on pilargids. DESCRIPTION Holotype complete, damaged, 5.5 mm long, 0.2 mm wide, 38 chaetigers. Because of the removal of chaetigers 1, 15, and 32, body breaking apart in those segments. Prostomium subtriangular (Fig. 6 A), wider than long, with three similar medially constricted antennae; lateral antennae placed in the middle of prostomium, on the base of palps, not reaching palp tips; median antenna on posterior prostomial margin. Palps free from base, rounded, each with subdistal ventral papillae (Figs 6 B; 7 A, C). Eyes not visible, but two large globular colourless structures present just behind lateral antennae. Nuchal organs placed in the outer external base of lateral antennae (Fig. 7 D). Peristomium with two pairs of similar tentacular cirri, as long as median antenna, because they are lateroventral, dorsal cirri looks longer than ventral one. Ciliary bundles extended laterally from the median antenna insertion, and two others extend over the dorsal surface of peristomium (Fig. 7 A-C). Anterior parapodia uniramous. Median and posterior parapodia biramous. Dorsal cirri digitate throughout the body, ventral cirri basally swollen in anterior and median chaetigers. Anterior parapodia (Fig. 6 C) with dorsal and ventral cirri with median constriction, of about same size; median (Fig. 6 D) and posterior chaetigers, with dorsal cirri larger, digitate, ventral cirri basally swollen. Anterior parapodia with two denticulate capillaries, two pectinates, and a furcate chaeta (Fig. 7 E). Following chaetigers with an emergent, brittle, sigmoid bidentate notospine (Fig. 6 F, G), first present from chaetiger 6, continued to posterior end, more exposed in posterior chaetigers (Fig. 7 G), each notospine with larger subdistal tooth; 1 or 2 finely denticulate capillaries and 1 or 2 pectinates per bundle (Fig. 6 E). Furcates with a flaring rounded blade, slightly longer than the tapering smaller tine, with dorsal keel curved, with a subdistal notch (Fig. 7 E, F). Posterior end with two prepygidial achaetous segments; pygidium with two ventrolateral anal cirri as long as last achaetous segment and pygidium (Figs 6 H; 7 H). Pharynx not everted. VARIATION Complete specimens were 3.0 - 5.5 mm long, about 0.15 mm wide, with 30 - 45 chaetigers, often with an achaetous prepygidial segment. Oocytes visible in chaetigers 13 - 23, along a line, each of about 25 - 30 µm in length. DISTRIBUTION Japan to Guam, in shallow sublittoral depths. This is a new record for the polychaete fauna of Guam, Mariana Islands (Bailey-Brock 2003). REMARKS Pseudexogone imajimai n. sp. resembles P. backstromi by having furcates with a thin smaller tine. These two species differ in the relative shape of both prostomia and in the blade in furcates. Thus, in P. imajimai n. sp. the prostomium is wider than long, and the dorsal keel of furcates blade is curved with a subdistal notch. In P. backstromi, on the contrary, the prostomium is longer than wide, and the dorsal keel of furcates is straight with a subdistal hump. Since furcates are very short, it would make them barely exposed to fractures, and their shape is diagnostic. In the holotype of P. imajimai n. sp., there are bifid curved notospines from chaetiger 6 (on the right side) though over the left side, most are broken and there is one left on chaetiger 9. This could explain the finding by Imajima (1987: 158).	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E0447149FFDFFEBFE2A3FB99DEDF.taxon	description	(Fig. 8)	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E0447149FFDFFEBFE2A3FB99DEDF.taxon	materials_examined	TYPE MATERIAL. — Eastern Pacific Ocean. USA, Bureau of Land Management Southern California Baseline Studies, off Southern California, Allan Hancock Foundation cruise 1341, RV Velero IV, stn 22979, 33 ° 50.88 ’ N, 119 ° 59.91 ’ W, 6.1 miles, 13 ° T to East Point, Santa Rosa Island, 78 m, box core, coarse biogenic sand with occasional pebbles, 15. X. 1975, holotype (LACM-AHF POLY 2184) and paratype (LACM-AHF POLY 2185). — Allan Hancock Foundation cruise 1341, RV Velero IV, stn 23039, 33 ° 52.97 ’ N, 120 ° 01.05 ’ W, 4.5 miles, 34 ° T to East Point, Santa Rosa Island, 57 m, box core, muddy fine sand with shell, 17. X. 1975, 1 paratype (23039 ECOSUR). — RV Thomas G. Thompson, stn 80901, 33 ° 46.2 ’ N, 119 ° 50.9 ’ W, NW slope Santa Cruz Basin, 22 km SSW of Gull Island, Santa Cruz Island, BLM 80, 222 - 271 m, sand, 21. VIII. 1977, 2 paratypes (LACM-AHF POLY 2186, another one ECOSUR). ADDITIONAL MATERIAL. — Eastern Pacific Ocean. California, Allan Hancock Foundation cruise 1341, RV Velero IV, stn 22943, 32 ° 44.05 ’ N, 119 ° 06.17 ’ W, 35.7 miles, 83.5 ° T to China Point, San Clemente Island, 319 m, box core, indurated mud and fine sand with rocks, 12. X. 1975, 1 specimen (LACM-AHF). — RV Thomas G. Thompson, stn 818 - 10, 32 ° 53.3 ’ N, 119 ° 23.4 ’ W, 34 km NW of pinnacle, Tanner Bank, California Channel Islands, 113 m, box core, shell and coarse sand, 24. VIII. 1977, anterior fragment (LACM-AHF).	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E0447149FFDFFEBFE2A3FB99DEDF.taxon	description	Western Mexico. Seamount studies (see Levin et al. 1994 for details; most in LACM-AHF), Alvin Dive 2318, Fieberling Guyot, 992 km W of San Diego, Sea Pen Rim, on northeast perimeter of top, box 1, Rep. 6, 0 - 1 cm, SPR, 32 ° 27.631 ’ N, 127 ° 49.489 ’ W, 636 m, basaltic and calcareous sands, 4. XII. 1990, 3 specimens (LACM-AHF). — Alvin dive 2318, box 1, Rep. C, 5 - 10 cm, SPR, 32 ° 27.631 ’ N, 127 ° 49.489 ’ W, 636 m, basaltic and calcareous sands, 4. XII. 1990, 1 specimen (LACM-AHF). — Alvin dive 2327, box 1, Rep. 8, 5 - 10 cm, 32 ° 27.631 ’ N, 127 ° 49.489 ’ W, 636 m, basaltic and calcareous sands, 13. XII. 1990, 1 specimen (LACM-AHF). — Alvin dive 2401, box 3, 1 - 2 cm, SPR, 32 ° 27.631 ’ N, 127 ° 49.489 ’ W, 636 m, basaltic and calcareous sands, 23. X. 1991, 1 specimen (LACM- AHF). — Alvin dive 2401, box 1, Rep. 8, 0 - 1 cm, SPR, 32 ° 27.631 ’ N, 127 ° 49.489 ’ W, 636 m, basaltic and calcareous sands, 27. X. 1991, 2 specimens (one gold-coated, ECOSUR, the other LACM-AHF). — Alvin dive 2322, White Sand Swale, 32 box 2, Rep. 1, 2 - 5 cm, WSS, 32 ° 27.581 ’ N, 127 ° 47.839 ’ W, 579 m, nearly white foraminiferal and calcareous sands, 8. XII. 1990, 1 specimen (LACM-AHF). — Alvin dive 2326, White Sand Swale, 32 box 2, Rep. C, 1 - 2 cm, 32 ° 27.581 ’ N, 127 ° 47.839 ’ W, 582 m, nearly white foraminiferal and calcareous sands, 12. XII. 1990, anterior fragment (LACM-AHF). — Alvin dive 2322, White Sand Swale, 32 box 5, Rep. A, 2 - 5 cm, WSS, 32 ° 27.581 ’ N, 127 ° 47.839 ’ W, 579 m, nearly white foraminiferal and calcareous sands, 8. XII. 1990, 2 specimens (LACM-AHF).	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E0447149FFDFFEBFE2A3FB99DEDF.taxon	materials_examined	TYPE LOCALITY. — Off Santa Rosa Island, Southern California, in shallow water.	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E0447149FFDFFEBFE2A3FB99DEDF.taxon	etymology	ETYMOLOGY. — This species name is made after Susan Williams who has worked during many years on Californian polychaetes, and who indicated that some of these specimens belong to an undescribed genus and species.	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E0447149FFDFFEBFE2A3FB99DEDF.taxon	description	DESCRIPTION Holotype complete, 32 mm long, 0.3 mm wide, 101 chaetigers. Prostomium corrugated in SEM specimens (Fig. 8 A, B), with palps irregularly wrinkled, free from each other; ventrolateral papillae directed laterally, slightly shorter than lateral antennae. All antennae cirriform, median one slightly longer than laterals; lateral antennae placed medially on prostomium, slightly ahead of median, median antennae placed over projected border on posterior margin of prostomium. One pair of eyes, each one placed on the inner side of the lateral antennae; original brown pigment faded, retina and lens visible. Tentacular segment biannulate, first ring laterally reduced; tentacular cirri ventrolaterally placed, dorsal cirrus slightly longer than ventral one. Ciliary bundles eroded. Chaetiger 1 biannulate, then mostly 3 - annulated to chaetiger 10, thereafter with 6 - 8 rings, continued to posterior end; less clearly noticeable in elongated segments. Parapodia uniramous in chaetigers 1 - 5, biramous thereafter. Dorsal and ventral cirri cirriform, dorsal ones longer. Chaetal lobe rounded with 4 - 6 neurochaetae; two elongated denticulate capillaries, two shorter pectinates, and two shorter furcates. Anterior parapodia (Fig. 8 C) with cirriform cirri, dorsal and ventral cirri of about same length; 1 or 2 denticulate capillaries and 1 or 2 pectinates; single furcate per bundle, with longer tine flared, blade margin straight, not reaching smaller digitate tine. Median chaetigers (Fig. 8 D) with bidentate curved notospines, clearly exposed along all body, present to last chaetiger; each notospine (Fig. 8 E, F) markedly curved with larger subdistal tooth and tiny distal tooth. Furcates apparently restricted to chaetigers 3 - 8. From chaetiger 6, slightly exposed bidentate curved notospine, becomes more exposed in posterior chaetigers. Posterior end with one achaetous segment (without it in SEM specimen, Fig. 8 G); pygidium rounded, as long as last two segments, anus dorsal, with two ventrolateral cirriform cirri, as long as pygidium. Brain posterior lobes long, separated, reaching the level of chaetal lobes of chaetiger 3. Pharynx not everted, about 1.5 chaetigers long. Few oocytes, singly in chaetigers 65 - 97, each about 30 µm. VARIATION Type and non-type specimens were 5 - 32 mm long, 0.23 - 0.30 mm wide, with 37 - 110 chaetigers. Most were thin but a few were markedly contracted showing highly annulated integument; other morphological features were unaltered. All had pale brown eyes placed at the inner side of lateral antennae, and bifid curved notospines from chaetiger 6. Mature females with large oocytes in posterior third of body; some specimens were small (AD 2318, Rep. C), being only 7.5 mm long with 39 chaetigers; one paratype (BFI 23039) being 11 mm long with 55 chaetigers, had oocytes in chaetigers 37 - 55. Oocytes were ovoid, about 30 µm long, with a small nucleus and showing different content and size of granules, or even hyaline, but always irregularly wrinkled (probably due to preservation). There was some variation in the amount of eggs per segment and these differences could be related to the steps between maturation and spawning.	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
03C5E0447149FFDFFEBFE2A3FB99DEDF.taxon	discussion	REMARKS Pseudexogone williamsae n. sp. resembles P. backstromi and P. imajimai n. sp. It differs from them by having furcates with a thick smaller tine.	en	Salazar-Vallejo, Sergio I., Bailey-Brock, Julie H., Dreyer, Jennifer C. (2007): Revision of Pseudexogone Augener, 1922 (Annelida, Polychaeta, Syllidae), and its transfer to Pilargidae. Zoosystema 29 (3): 535-553, DOI: http://doi.org/10.5281/zenodo.4689932
