Muséum d'histoire naturelle, case postale 6434, CH-1211 Genève 6, Switzerland.

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1 Zootaxa : (2006) Copyright 2006 Magnolia Press ISSN (print edition) ZOOTAXA ISSN (online edition) A taxonomic revision of the family Oncopodidae VI. Martensiellus, a new genus from Borneo, and the discovery of a tarsal pore organ in Oncopodidae (Opiliones: Laniatores) PETER J. SCHWENDINGER Muséum d'histoire naturelle, case postale 6434, CH-1211 Genève 6, Switzerland. peter.schwendinger@ville-ge.ch Abstract A new genus, Martensiellus, is established for Martensiellus tenuipalpus n. sp. from central Sarawak. The distad-directed, expandable glans penis of this species indicates a close relationship with Biantoncopus fuscus Martens & Schwendinger from the Philippines. Females of two other species from eastern Sarawak and southern Kalimantan, which presumably also belong to Martensiellus n. g., are presented but not formally described. A dorsal pore, similar to the pore organ of Ricinulei, is reported to be present on undivided leg tarsi of mature specimens of Martensiellus tenuipalpus n. sp.,?martensiellus n. g. spp., Palaeoncopus spp., Caenoncopus spp. and Oncopus spp. This character is considered as apomorphic for Oncopodidae, providing further support for monophyly of this family. Key words: Arachnida, taxonomy, Sarawak, Kalimantan Introduction During the last eight years I have enjoyed a most pleasant and fruitful co-operation with Prof. Dr Jochen Martens (University of Mainz, Germany), which resulted in six publications on the opilionid family Oncopodidae (Martens & Schwendinger 1998, Schwendinger & Martens 1999a, Schwendinger & Martens 1999b, Schwendinger & Martens 2002a, Schwendinger & Martens 2002b, Schwendinger & Martens 2004). Two more joint papers (Schwendinger & Martens in press, a, b) will appear soon and others shall follow. The oncopodid material currently available for our joint-project contains plenty of undescribed species, at least one of which clearly belongs to a new genus. As a gesture of gratitude and in appreciation of Prof. Martens outstanding contribution to taxonomy and systematics of the order Opiliones, I dedicate this new genus to him. Accepted by P. Jäger: 25 Jul. 2006; published: 28 Sept

2 ZOOTAXA Material and methods The material examined is deposited in the following institutions (abbreviations in parentheses): American Museum of Natural History, New York, USA (AMNH); Muséum d'histoire naturelle, Genève, Switzerland (MHNG). Body measurements refer to the dorsal scutum. Leg articles were measured on their dorsal side, from joint to joint. All measurements are given in mm. The tarsal formula is given from leg I to leg IV. The term carapace-opisthosoma bridge is here used instead of carapace-abdomen bridge (see Schwendinger & Martens 1999b: 946). Terminology of penis morphology follows Martens & Schwendinger (1998: fig. 1). Somatic structures were studied and drawn with a ZEISS SV11 stereomicroscope, penes, as temporary mounts embedded in glycerine, with a NIKON Optiphot compound microscope (each with a drawing tube). The penis of the male paratype was expanded by first placing it in hot (not boiling) lactic acid for about five minutes and then transferring it to distilled water at room temperature. Expansion of the paratype penis lasted only for a few seconds (probably due to stiffness from long-term preservation in alcohol); expansion could not be provoked in the penis of the holotype. Taxonomy Oncopodidae Thorell, 1876 Type genus. Oncopus Thorell, 1876; type species by original designation and by monotypy, Oncopus doriae Thorell, Remark. The name of the type genus, Oncopus Thorell, 1876 (without a synonym), is pre-occupied by Oncopus Herrich-Schäffer, 1855 (with a synonym) for a genus of South American geometrid moths with two species. Substituting Oncopus Thorell by a new name, as proposed by Özdikmen & Kury (in press), would result in several other nomenclatural changes: Mandatory new combinations for twelve species names, two of which are currently in synonymy and one of which, Oncopus cuspidatus Schwendinger, is the type species of the genus Caenoncopus Martens & Schwendinger, plus the corresponding replacement of the family name Oncopodidae Thorell and of the superfamily name Oncopodoidea Thorell. Oncopus Thorell is a widely used name, which is not the case in Oncopus Herrich-Schäffer. Therefore the International Commission on Zoological Nomenclature has been asked to use its plenary powers to suppress the senior homonym (Schwendinger & Martens in press, a). Receipt of this case was published in September 2005 (International Commission on Zoological Nomenclature 2005: 126). As long as this matter is under consideration by the Commission, the prevailing usage of names has to be maintained [see Article 82 of the current edition of the International Code Magnolia Press SCHWENDINGER

3 of Zoological Nomenclature (International Commission on Zoological Nomenclature 1999)]. ZOOTAXA FIGURES 1 3. Martensiellus tenuipalpus n. g., n. sp., male holotype, habitus (1 dorsal view, 2 ventral view, 3 lateral view). Scale bar: 1 mm. ONCOPODIDAE 2006 Magnolia Press 257

4 ZOOTAXA Martensiellus n. g. Type species. Martensiellus tenuipalpus n. sp. Etymology. The generic name (male in gender) is derived from the name Martens. Diagnosis. The new genus is characterized by the following combination of characters: 1. The penis carries an expandable, distad-directed glans in which the median plate lies dorsally of the lateral sclerites (Figs 11 17). The same is found in Biantoncopus Martens & Schwendinger, whereas in the distad-directed glans of Palaeoncopus Martens & Schwendinger the plate lies ventral to the sclerites. 2. A dorsal pore is present on tarsi of legs I and II, as is also the case in Palaeoncopus and Caenoncopus. In Oncopus dorsal pores are present on all leg tarsi. In Gnomulus Thorell and Biantoncopus tarsal pores are absent. 3. The tarsal formula is (as in Caenoncopus cuspidatus), all tarsi/ tarsomeres are large. In lateral view the undivided tarsi of legs I and II in Martensiellus n. g. are ovoid, clearly longer than deep (Figs 6 7), whereas in Caenoncopus they both are semiglobular and clearly deeper than long (see Martens & Schwendinger 1998: fig. 4c). In Oncopus (see Thorell 1891: figs 34 35) and, less distinctly so, in Palaeoncopus the tarsus of leg I is slightly longer than deep and the tarsus of leg II slightly deeper than long. Tarsomeres of legs III and IV in Martensiellus n. g. are fairly long and large, only slightly less deep than the corresponding metatarsi in their proximal portion (Figs 8 9). This is also the case in Gnomulus (see Silhavy 1962: fig. 4) and Biantoncopus (see Martens & Schwendinger 1998: fig. 69), whereas in Caenoncopus (see Martens & Schwendinger 1998: figs 4b, d) and Palaeoncopus the tarsomeres of legs III and IV are short and small, only about half as deep as the corresponding metatarsi. Species account and distribution. At the moment only one species from central Sarawak can be unequivocally attributed to the new genus. Females of two different species from eastern Sarawak and southern Kalimantan (see paragraph Martensiellus n. g. spp. ) presumably also belong there, but generic placement without males is uncertain. Several more species of this new genus are expected to occur in different parts of Borneo. Martensiellus tenuipalpus n. sp. Figs 1 17 Oncopodidae g. sp.: Schwendinger & Martens 2002b: figs 50 51, 59. Types. Male holotype (AMNH) and male paratype (ventral scutum broken; MHNG; ex AMNH, donated by L. Prendini) from Eastern Malaysia, Sarawak, Baleh River, north of Kapit, 40 m, collected 25 June 1976 by Walter C. Sedgwick. Etymology. The specific epithet, a noun in apposition formed from the Latin tenuis (= thin, slender) and palpus (= feeler), refers to the unusually slender palpal tarsus of males in this species. Diagnosis. Externally similar to Caenoncopus cuspidatus (see Schwendinger 1992: Magnolia Press SCHWENDINGER

5 , figs 76 80; Martens & Schwendinger 1998: 507, figs 4c f, 5 8), but with stronger pilosity; no carapace-opisthosoma bridge; eye mound (tubercle) distinctly elevated; carapace region fairly large; ventral scutal areas distinctly elevated; anteroproximal process on coxa III present; genital operculum small (Figs 1 3); palpus with distinct ventral process on trochanter, no process on femur, tarsus exceptionally thin in distal portion; leg tarsi/tarsomeres (Figs 4 10) much longer and larger than in C. cuspidatus. Penis similar to that of Biantoncopus fuscus Martens & Schwendinger (see Martens & Schwendinger 1998: , figs 58 70), but glans wider, situated more distally, with indistinct membranous socket, wider lateral sclerites and narrower median plate (Figs 11 17). Description. Male (holotype). Colouration (in alcohol) and surface texture: Ground colour light orange, with indistinct darker pattern on dorsal scutal elevations (probably lightened by long-time preservation in alcohol; Fig. 1). A finely granular surface on prosoma, genital operculum, chelicera (except for fingers), legs and palpus (except for tarsi). Carapace region with rounded, slightly anteriad-inclined eye tubercle carrying a small pointed tip; carapace-opisthosoma bridge absent; no lateral tubercles in posterior part of carapace region. Dorsal scutal areas of opisthosoma region only indistinctly elevated; ventral scutal areas moderately swollen and pallid (Fig. 3). Ventral scutum and opisthosoma region of dorsal scutum densely covered by short hairs (Figs 1 3). Palpal coxa with small ventral process; leg coxa I with indistinct anterolateral process; leg coxae II and III with distinct anteroproximal processes, no posteroproximal process on coxa II (Fig. 2); dorsal side of leg coxa IV without tubercles. Genital operculum somewhat triangular, wider than long; posterior margin of stigmatic pit without tubercle (Fig. 2). Chelicera (Fig. 4): Hand weak, with a few small hairs dorsally; proximal article with a higher dorsodistal and a lower dorsomedian boss, no ventral process. Palpus (Fig. 5): Trochanter with slightly distad-inclined ventral process; femur short, with indistinct, broadly rounded ventroproximal boss, no process; tarsus cylindrical, exceptionally thin in distal half, there about as deep and wide as claw (possibly a sexual dimorphism). Legs (Figs 6 9) 1342 (from shortest to longest), tarsal formula ; tarsi I and II somewhat ovoid (Figs 6 7), with a deep pore dorsally; tarsus of leg II about 1.6 times longer than deep (Fig. 7). Penis (Figs 11 14): Truncus fairly robust, slightly constricted midway, from there widening to a second moderate constriction below glans; distal margin of truncus widely rounded; several subapical setae laterally, two on each side separated from other setae and flanking proximal part of glans. Glans distad-directed, wider than truncus at that point, slightly projecting beyond distal margin of truncus; lateral sclerites wide, somewhat scoop-shaped, their outer part flat and their inner part projecting dorsad; median plate rectangular, longer than wide (visible only in expanded state; see Fig. 16 for paratype), lying dorsally of lateral sclerites (as in Biantoncopus, but not in Palaeoncopus); stylus ZOOTAXA ONCOPODIDAE 2006 Magnolia Press 259

6 ZOOTAXA slender, with bifid tip but without pair of subapical teeth; membranous tubes wide, distally truncate and bent dorsad, lying between stylus and a somewhat pentagonal median knob. In expanded state (see Fig. 16 for paratype) median plate and stylus of glans protruding distad, and membranous tubes folded posteriad, as in the penis of Biantoncopus fuscus Martens & Schwendinger (see Martens & Schwendinger 1998: figs 64 65). FIGURES Martensiellus tenuipalpus n. g., n. sp., male (4 9 holotype, 10 paratype). 4. Chelicera, lateral view. 5. Palpus, lateral view. 6. Distal parts of legs, lateral view ( 6 leg I, 7 leg II, 8 leg III, 9 leg IV). 10. Palpus and anterior part of body, lateral view. Scale bars: 1 mm (4 9 same scale). Measurements of male holotype (male paratype in parentheses): Body 3.51 (3.47) long, 2.18 (2.18) wide; carapace region 1.04 (1.02) long, 1.30 (1.30) wide; palpus and legs: Trochanter Femur Patella Tibia Metatarsus Tarsus Total Palpus Leg I Leg II Leg III Leg IV Female. Unknown. Variation. The male paratype is more strongly pigmented than the holotype. Its ground colour is amber, with dark brown horizontal bands on dorsal scutum and with a dark reticulation in the carapace region; leg femora to metatarsi are darkened, leg tarsi and palpal tarsus light brown; its ventral body side is mostly amber, only the lateral margin of Magnolia Press SCHWENDINGER

7 the ventral scutum and patches behind coxa IV and genital operculum are darkened. The ventral process on the palpal trochanter of the paratype is ventrad-directed (Fig. 10) rather than slightly distad-directed as in the holotype (Fig. 5). The penis of the paratype has a slightly more rounded distal margin (Figs 15 16), but otherwise it is very similar to that of the holotype (Fig. 13). ZOOTAXA FIGURES Martensiellus tenuipalpus n. g., n. sp., penis (11 14 holotype, paratype) Total penis (11 dorsal view, 12 lateral view) , 17. Apex of penis in resting position (13, 15 dorsal view, 14, 17 lateral view). 16. Apex of penis with expanded glans, dorsal view. Abbreviations: d.m. distal margin of truncus penis, l.s. lateral sclerite of glans, m.p. median plate of glans, m.t. membranous tubes of glans, s stylus. Scale bars: 0.5 mm (11 12), 0.1 mm (13 17). Relationships. The presence of a distinctly derived penis with a distad-directed, expandable glans in which the median plate lies dorsally of the lateral sclerites, shows that Martensiellus n. g. from Borneo is phylogenetically closest to Biantoncopus from the Philippines (see Schwendinger & Martens 2002b: fig. 59; Martensiellus tenuipalpus n. sp. under Oncopodidae g. sp.). In its somatic morphology however, the new genus is rather conservative and more similar to Palaeoncopus (with primitive penis morphology) and Caenoncopus (with extremely derived penis morphology), which both occur in Sumatra. ONCOPODIDAE 2006 Magnolia Press 261

8 ZOOTAXA Distribution. Known only from the environs of Kapit in central Sarawak.?Martensiellus n. g. spp. Figs Two females from other parts of Borneo possess the same characteristics in somatic morphology (tarsal formula , leg tarsi/tarsomeres fairly large, a tarsal pore present on legs I and II) that place M. tenuipalpus n. sp. apart from all other described oncopodid species. I assume that these females also belong to Martensiellus n. g. and represent two undescribed species distinct from M. tenuipalpus n. sp. However, generic placement without conspecific males is uncertain and I therefore refrain from formally describing and naming them. FIGURES ?Martensiellus n. g. spp., female from Mulu N.P. (18, 19), female from Kaharian (20 22). 18. Anterior part of body and proximal part of palpus and of chelicera, lateral view. 19, 22. Distal part of leg II, lateral view. 20. Anterior part of body and proximal part of palpus, lateral view; 21. Chelicera, retrolateral view. Scale bars: 1 mm (18 19, same scale). 1. female (MHNG): Eastern Malaysia, Sarawak, Mulu National Park, near headquarters (4 00 N, E), 200 m, collected on August 2003 from rain forest leaf litter by A. Schulz. Different from the males of M. tenuipalpus n. sp. by: Body distinctly smaller (2.75 mm long); eye tubercle more conical (Fig. 18); legs more slender and palpal tibia thicker; carapace-opisthosoma bridge present, divided; tiny process on palpal trochanter; distinct ventral process on proximal article of chelicera (Fig. 18); tarsus Magnolia Press SCHWENDINGER

9 of leg II relatively longer (Fig. 19). 2. female (collection of C. Deeleman-Reinhold; mentioned in Martens & Schwendinger 1998: 548): Indonesia, Central Kalimantan Province, Kaharian (2 02 S, E), collected from the leaf litter of a swampy primary forest on 2 16 October 1985 by S. Djojosudharmo. Different from males of M. tenuipalpus n. sp. by: Body much larger (5.19 mm long); eye tubercle broadly rounded; carapace-opisthosoma bridge present, undivided (Fig. 20); legs more slender and papal tibia thicker; process on palpal trochanter large, bifid (Fig. 20); chelicera more robust, with distad-directed dorsodistal process on proximal article and ventrodistal process on second article (Fig. 21). Tarsus of leg II (Fig. 22) similar to that of M. tenuipalpus n. sp. (Fig. 7). ZOOTAXA Tarsal pore Examination of the new species under a light microscope revealed the presence of a small dot-like structure in the proximal half of the dorsal side of leg tarsi I and II. SEMexamination of the right tarsus I of the presumably congeneric female from Kaharian showed that the dot is actually an elliptic pore, more than twice as wide as it is long, surrounded by a hairless area (Figs 23 24). The pore leads into a deep pit partly filled with a shapeless mass, which is probably a coagulated secretion (Fig. 25). Subsequently I found such pores also on tarsi I and II of mature Palaeoncopus and Caenoncopus specimens, and on all leg tarsi of mature Oncopus specimens. These pores appear to be present only on undivided tarsi of some oncopodid genera (not in Gnomulus and Biantoncopus, which have all leg tarsi divided), and only in mature specimens of both sexes. No pores could be found in juveniles. In some Oncopus specimens the pores are completely filled and capped with a coagulated dome-shaped mass (in some specimens reaching the dorsodistal margin of the metatarsus), which clearly consists of a secretion. Tarsal organs, which serve as olfactory, thermosensitive, hygrosensitive and mechanosensitive receptors, are known from several arachnid orders (Scorpiones, Araneae, Amblypygi, Ricinulei and some Acari; Talarico et al. 2005: 609), but have not been reported from Opiliones before. The closest thing to a tarsal organ so far known in opilionids is the first (or first and second) spindle-shaped basitarsomere of leg I in males of Manaosbiidae (Kury & Pinto-da-Rocha 2002: 347, 354, fig. 3). This contains a large gland (personal communication by R. Pinto-da-Rocha and G. Machado), but its presence is sexspecific, probably apomorphic for Manaosbiidae, and thus not comparable with tarsal pores in Oncopodidae. The same possibly also holds true for the thickened second tarsomere on leg I in males of Triaenopodium tarsalis Roewer (Trionyxellidae) (see Roewer 1923: fig. 249b). Conspecific females (specimens from Singapore in MHNG examined) have normal tarsomeres on leg I. The male holotype of Holoscotolemon fusitarsus Roewer (Cladonychiidae) (currently in the synonymy of H. unicolor Roewer) from Austria also possesses a spindle-shaped proximal tarsomere, but on leg III rather than leg I or II (Roewer 1949: 289, fig. 100e). ONCOPODIDAE 2006 Magnolia Press 263

10 ZOOTAXA FIGURES ?Martensiellus n. g. sp., female from Kaharian. SEM-micrographs of right tarsus I showing dorsal pore at different enlargements. Scale bars: 100 µm (23), 20 µm (24), 5 µm (25). The internal structure of oncopodid tarsal pores is still unknown. Externally they appear to be quite similar to the pore organs found on the distal tarsomere of legs I and II in Ricinulei. Talarico et al. (2005) recently gave a thorough account of the tarsal pore structure in two ricinuleid species, Pseudocellus pearsei (Chamberlin & Ivie) and P. boneti (Bolivar & Pieltain), but the function of this organ remains unclear. Talarico et al. (2005) Magnolia Press SCHWENDINGER

11 assume that the ricinuleid pore organ is a pheromone receptor, because it is absent in the 6- legged larva (= first postembryonic instar outside the egg). They interpret the secretion inside the pore as a liquid that binds odorants and cleans the hair sensilla (not visible in the oncopodid specimen examined with SEM) at the bottom. A similar internal structure and function can be expected for the tarsal pores of Oncopodidae. The apparent absence of such a structure in all juvenile instars of oncopodids is an indication of some kind of sexual function. A related function (pheromone dispersal?) is presumed for the glandular hairs in the opisthosoma region of the ventral scutum in males of some oncopodid species (Schwendinger & Martens 1999: 954, figs 69a, b). Both structures deserve further investigation. Tarsal pores in Opiliones are currently known only from Oncopodidae, a highly derived group of hemolymph-pressure Laniatores (characterized by the apomorphic loss of penis musculature), and not from any of the more basal taxa. The presence of this structure is therefore regarded as a fourth apomorphy (in addition to: Lateral sclerites of glans penis connected by a median plate, ovipositor laterally compressed, carapaceopisthosoma bridge present; see Martens & Schwendinger 1998: 502) that further supports monophyly of this family, despite its exceptional diversity in male genitalia (see Schwendinger & Martens 2002b). ZOOTAXA Acknowledgements I am grateful to Jochen Martens (University of Mainz, Germany) for his encouragement to work on this fascinating group of opilionids, for his co-operation and for his supply of material. Peter Jäger (Forschungsinstitut und Naturmuseum Senckenberg, Frankfurt, Germany) kindly invited me to contribute to this volume. William A. Shear (Hampden- Sydney College, USA) sorted out several oncopodids (including the two types of the new species described here) from the opilionid collection of the AMNH and sent them to me. Norman I. Platnick (AMNH, former curator of Opiliones) allowed me to dissect and study this material, and Lorenzo Prendini (AMNH, current curator of Opiliones) generously donated the paratype of the new species to the MHNG. Christa Deeleman-Reinhold (Ossendrecht, The Netherlands) and Andreas Schulz (Leverkusen, Germany) provided the?martensiellus n. g. spp. females. André Piuz (MHNG) produced the SEM-micrographs; Käthe Rehbinder (Mainz) drew the habitus; Corinne Charvet (HMNG) scanned the images; John Hollier (MHNG) checked the English text. Ricardo Pinto-da-Rocha (Museu de Zoologia, São Paulo, Brazil) and Glauco Machado (Universidade Estadual de Campinas, Brazil) informed me about spindle-shaped tarsalia containing a gland in Manaosbiidae; Jürgen Gruber (Natural History Museum, Vienna, Austria) pointed out a similar modification in Cladonychiidae. W. A. Shear and J. Gruber commented on an earlier version of this paper and helped to improve it. ONCOPODIDAE 2006 Magnolia Press 265

12 ZOOTAXA References International Commission on Zoological Nomenclature (1999) International Code of Zoological Nomenclature (fourth edition). International trust for Zoological Nomenclature, London, 306 pp. International Commission on Zoological Nomenclature (2005) New applications to the Commission. Bulletin of Zoological Nomenclature, 62(3), Kury, A.B. & Pinto-da-Rocha, R. (2002) 4.4 Opiliones. In: Adis, J. (Ed.), Amazonian Arachnida and Myriapoda. Pensoft Publ., Moscow, Martens, J. & Schwendinger, P.J. (1998) A taxonomic revision of the family Oncopodidae I. New genera and new species of Gnomulus Thorell (Opiliones, Laniatores). Revue suisse de Zoologie, 105(3), Özdikmen, H. & Kury, A.B. (in press) A new family and genus name for Laniatores (Arachnida, Opiliones). Journal of Arachnology. Roewer, C.-F. (1923) Die Weberknechte der Erde. Systematische Bearbeitung der bisher bekannten Opiliones. Fischer, Jena, IV+1116 pp. Roewer, C.-F. (1949) Über Phalangodidae II. Weitere Weberknechte XIV. Senckenbergiana, 30(4/ 6), Schwendinger, P.J. (1992) New Oncopodidae (Opiliones, Laniatores) from Southeast Asia. Revue suisse de Zoologie, 99(1), Schwendinger, P.J. & Martens, J. (1999a) A taxonomic revision of the family Oncopodidae II. The genus Gnomulus Thorell (Opiliones, Laniatores). Revue suisse de Zoologie, 106(4), Schwendinger, P.J. & Martens, J. (1999b) Case Gnomulus Thorell, 1890 (Arachnida, Opiliones): proposed designation of G. sumatranus Thorell, 1891 as the type species. Bulletin of Zoological Nomenclature, 56(3), Schwendinger, P.J. & Martens, J. (2002a) A taxonomic revision of the family Oncopodidae III. Further new species of Gnomulus Thorell (Opiliones, Laniatores). Revue suisse de Zoologie, 109(1), Schwendinger, P.J. & Martens, J. (2002b) Penis morphology in Oncopodidae (Opiliones, Laniatores): evolutionary trends and relationships. Journal of Arachnology, 30, Schwendinger, P.J. & Martens, J. (2004) A taxonomic revision of the family Oncopodidae IV. The genus Oncopus Thorell (Opiliones, Laniatores). Revue suisse de Zoologie, 111(1), Schwendinger, P.J. & Martens, J. (in press, a) Case Oncopus Thorell, 1876 and Oncopodidae Thorell, 1876 (Arachnida, Opiliones): proposed conservation. Bulletin of Zoological Nomenclature. Schwendinger, P.J. & Martens, J. (in press, b) A taxonomic revision of the family Oncopodidae V. Gnomulus from Vietnam and China, with the description of five new species (Opiliones, Laniatores). Revue suisse de Zoologie. Silhavy, V. (1962) Un opilion nouveau, Pelitnus drescoi n. sp. (Fam. Oncopodidae). Bulletin du Muséum National d'histoire Naturelle, ser. 2, 34(6), Talarico, G., Palacios-Vargas, J.G., Fuentes Silva, M. & Alberti, G. (2005) First ultrastructural observations on the tarsal pore organ of Pseudocellus pearsei and P. boneti (Arachnida, Ricinulei). Journal of Arachnology, 33, Thorell, T. (1891) Opilioni nuovi o poco cognosciuti dell'archipelago Malese. Annali del Museo Civico di Storia Naturale di Genova, ser. 2, 10, , plates VIII, IX Magnolia Press SCHWENDINGER