taxonID	type	description	language	source
039787E32E17FFA5FF7B1B2AFDE7F9E2.taxon	materials_examined	Type species: Gamasus heterotarsus G. Canestrini, 1897, by monotypy.	en	Kazemi, Shahrooz, Nasr, Abdelrady Korashy, Ramadan, Mahmoud Mohamed, Klompen, Hans (2021): Review of the genus Sessiluncus (Acari: Mesostigmata: Ologamasidae), description of male and redescription of female of Sessiluncus aegypticus, and notes on some morphological characters of the genus. Zootaxa 5061 (2): 271-299, DOI: https://doi.org/10.11646/zootaxa.5061.2.3
039787E32E17FFA5FF7B1B2AFDE7F9E2.taxon	diagnosis	Diagnosis (female and male). Holonotal shield free from ventrianal shield, no indication of fusion line between podonotal and opisthonotal shield regions; bearing 35 – 39 pairs of short to moderately long and usually acicular setae, smooth or slightly pilose, with 21 pairs of pore-like structures, including four pairs of glandular openings, gd 1, gd 5 – gd 6, and gd 8 or gd 9; with one pair of pit-like cuticular structures, “ pcs ”, between setae J 1 – J 2. One pair of presternal plates, free or fused to sternal shield. Ventrianal shield free, capturing metapodal platelet. Peritrematal shield free posteriorly, with two crenate lateral projections at level of coxae II – III (Figures 2, 13, 26, 40). Peritreme straight or sinuous. Anterior margin of gnathotectum subtriangular, denticulate. Male spermatodactyl strongly recurved near the base (Figures 4, 30). Deutosternal row between setae h 3 denticulate medially, extending laterally into smooth ridges (Figures 17, 31, 54). Pretarsus I sessile. Femur I with 13 setae; genua I and III with 13 and 8 setae, respectively; genu and tibia IV each with 8 – 10 setae. Some leg segments in male and female may bear modified setae or cuticular spurs.	en	Kazemi, Shahrooz, Nasr, Abdelrady Korashy, Ramadan, Mahmoud Mohamed, Klompen, Hans (2021): Review of the genus Sessiluncus (Acari: Mesostigmata: Ologamasidae), description of male and redescription of female of Sessiluncus aegypticus, and notes on some morphological characters of the genus. Zootaxa 5061 (2): 271-299, DOI: https://doi.org/10.11646/zootaxa.5061.2.3
039787E32E17FFA5FF7B1B2AFDE7F9E2.taxon	description	Description (adults). Medium size mites (440 – 810 long). Idiosoma suboval, covered by a holonotal shield, occasionally slightly extending ventrally (a narrow band of dorsolateral soft cuticle present in S. reticulatus, bearing 1 – 2 pairs of setae posterolaterally in addition to two pairs of setae on ventrolateral soft cuticle), and free from ventrianal shield; shield usually with one pair of small, short and irregular projections anterolaterally, flanking a narrow sclerotised band bordering shield anteriorly, sometimes divided into small platelets / strips (Figures 1, 3, 9, 25, 26, 53). Holonotal shield bearing 35 – 39 pairs of short to moderately long acicular setae, smooth or slightly pilose, rarely finely flatted near the tip (S. oculatus, Figure 46), setae z 1 usually absent (maybe present in S. heterotarsus); with 21 pairs of pore-like structures, comprising 17 pairs of poroids (id 1 – id 2, id 4 – id 6, idm 1 – idm 6, is 1, idx, idl 1 – idl 4), and four pairs of gland pores, gd 1, gd 5 – gd 6, and gd 8 or gd 9. One pair of pit-like cuticular structures, “ pcs ”, present between setae J 1 – J 2. Tritosternal base short; laciniae free, pilose. Presternal platelets well sclerotised, subrectangular, flanking base of tritosternum, free or fused to sternal shield. Sternal shield in female large, fused to endopodal elements between coxae I – IV, rarely free from endopodal between coxae III – IV (as in undescribed species from Nepal (Lee 1970) and Iran (Kazemi collection, description in progress); shield fused to continuous exopodal strip behind acetabula I – IV via endopodal element between coxae I – II, bearing gland pore gvb; sternal shield extending posteriorly and internally into the genital chamber as a horse-shoe shaped structure (Figures 28, 39). Male sternal shield usually fused posteriorly to the continuous exopodal strip via parapodal element (Figures 2, 26). Sternal shield of female with four pairs of setae and three pairs of poroids and that of male with five pairs of setae and three pairs of poroids; gland pore gv 1 indistinct. Epigynal shield flanked by sternal and ventrianal shields, convex anteriorly and truncate posteriorly, with one pair of setae. Postgenital platelets absent. Ventrianal shield large, free, usually bearing six, rarely five or nine pairs of ventral setae in addition to circumanals; gland pore gv 2 distinct or indistinct, gv 3 absent (Figures 2, 13, 27). Metapodal platelet fused to ventrianal shield. Soft cuticle laterad ventrianal shield with 0 – 2 pairs of setae. Peritrematal shield free posteriorly, but anteriorly fused to dorsal shield at level of coxa II; with two crenate lateral projections; poststigmatal region well developed, sometimes extending well behind anterior margin of ventrianal shield, with one poroid and one distinct, large gland pore (Figure 2, 13, 26, 40). Peritreme relatively narrow, straight or sinuous, extending to midlevel of coxa II or up to level of coxa I. Gnathotectum anterior margin usually with a median subtriangular prong flanked by one pair or a few shorter lateral projections (Figures 41 – 44), occasionally projections less distinct (Figures 29, 53). Corniculus horn-like, simple (Figure 30) or with a lateral prong or tooth submedially (Figure 55). Movable digit of chelicera in female bearing three teeth, fixed digit usually with four teeth, rarely with two, three (?) or five teeth. Movable digit of chelicera in male with two teeth, rarely one, fixed digit with 3 – 5 teeth. Male spermatodactyl strongly recurved near the base (Figures 4, 30). Deutosternal groove with 8 – 9 rows, the row between setae h 3 narrowly denticulate, extending laterally into smooth ridges, 5 – 6 posterior rows usually markedly wider; with two smooth or denticulate posterolateral transverse ridges connected to deutosternum groove (Figures 17, 31, 54). Leg I longer than legs II – IV, and not attenuated; legs I and II usually thicker than legs III – IV; pretarsus I sessile, not pedunculate, its base broadly fused to tarsus (Figures 5, 48). Lateral and median lobes of pulvilli on legs I – IV rounded apically, lateral lobes longer than median lobe. Tarsi II – IV each with three small apicoventral projections (two lateral and one median), median one occasionally denticulate apically (Figures 10 – 12). Setation of femora I – IV 13 (2 3 / 1, 2 / 3, 2), 11 (2, 3 / 2, 2 / 1, 1), 6 (1, 2 / 1, 2 / 0, 0), 6 (1, 2 / 1, 1 / 0, 1), those of genua I – IV 13 (2, 3 / 2, 3 / 1, 2), 11 (2, 3 / 1, 2 / 1, 2) or rarely 12 (2, 3 / 2, 2 / 1, 2) [S. reticulatus Loots (1980)], 8 (2, 2 / 1, 2 / 0, 1), 9 (2, 2 / 1, 3 / 0, 1) or 10 (2, 2 / 1, 3 / 0, 2) or rarely 8 (2, 1 / 1, 3 / 0, 1) [S. reticulatus Loots (1980)], and those of tibiae I – IV 14 (2, 3 / 2, 3 / 2, 2), 10 (2, 2 / 1, 2 / 1, 2) or rarely 11 (2, 2 / 2, 2 / 1, 2) [S. reticulatus, Loots (1980)], 8 (2, 1 / 1, 2 / 1, 1), 9 (2, 1 / 1, 3 / 1, 1) or 10 (2, 1 / 1, 3 / 1, 2) (e. g. as in S. hungaricus), or rarely 8 (1, 1 / 1, 3 / 1, 1) (S. oculatus) or (2, 1 / 1, 2 / 1, 1) [S. reticulatus Loots (1980)], respectively. Some leg segments in female (especially trochanter IV) may bear modified setae or cuticular spurs (Figures 23, 35, 49 – 51). Male with at least one large ventral spur on femur II (modified seta av) and III, seta av on genu and tibia II usually knob-like (Figures 6 – 8, 37) (more details in Table 1). The following species (and country of type locality) are considered as members of Sessiluncus: S. abalaae Datta & Bhattacharjee, 1991 (India); S. aegypticus Nasr & Afifi, 1986 (Egypt); S. bengalensis Bhattacharyya, 1977 (India); S. calcuttaensis Bhattacharyya, 1977 (India); S. cavensis Willmann, 1940 (Bosnia and Herzegovina); S. colchicus Bregetova, 1977 (Russia); S. femoralis Bhattacharyya, 1977 (India); S. heterotarsus (G. Canestrini, 1897) [described as Gamasus heterotarsus] (Papua New Guinea); S. hungaricus Karg, 1964 (Hungary); S. indicus Bhattacharyya, 1977 (India); S. leei Datta & Bhattacharjee, 1991 (India); S. oculatus Vitzthum, 1935 (Tahiti, French Polynesia); S. reticulatus Loots, 1980 (Seychelles); S. yongchunensis Ma & Zhang, 2013 (China).	en	Kazemi, Shahrooz, Nasr, Abdelrady Korashy, Ramadan, Mahmoud Mohamed, Klompen, Hans (2021): Review of the genus Sessiluncus (Acari: Mesostigmata: Ologamasidae), description of male and redescription of female of Sessiluncus aegypticus, and notes on some morphological characters of the genus. Zootaxa 5061 (2): 271-299, DOI: https://doi.org/10.11646/zootaxa.5061.2.3
039787E32E17FFA5FF7B1B2AFDE7F9E2.taxon	discussion	Remarks on the genus. The genus Sessiluncus can be easily distinguished from all other ologamasid genera by a combination of characters described in the genus diagnosis above, especially the sessile pretarsus I (ambulacral stalk almost absent) that is broadly fused to the tarsus basally, while the pretarsus I is pedunculate (ambulacral stalk well developed) in most other ologamasid genera (when ambulacrum is present), except in a few species described in Gamasellevans (Loots & Ryke 1967). Additionally, the peritrematal shield in all examined species of Sessiluncus has two lateral crenate projections that are not present or not described in other ologamasid genera (partially present in a Rykellus sp.). Also, if the structure of the deutosternal row between setae h 3 (narrowly denticulate medially and extending into smooth ridges laterally) is not unique within the family (based on the published data) it is certainly rare (again, partially present in the same Rykellus sp.). We recognise 14 valid species in the genus Sessiluncus. Another species that was previously considered as a member of the genus is S. holostaspoides (G. Canestrini, 1884) (e. g. by Bregetova 1977; Castilho et al. 2016; Beaulieu et al. 2019). Laelaps holostaspoides was described by Canestrini in 1884, but without illustrations. Berlese (1892) redescribed L. holostaspoides, including information almost identical to that provided by Canestrini (1884), but he added an illustration of the venter of this species. Berlese’s (1892) illustration shows a pedunculate (not sessile) ambulacrum I. A sessile pretarsus is the main diagnostic feature of Sessiluncus. Therefore, we excluded this species from Sessiluncus. Seta z 1 appears to be absent in most of the known species of Sessiluncus ¸ but it is listed in the original descriptions of S. hungaricus and S. aegypticus. Notably, based on examination of the holotype of S. hungaricus, seta z 1 is absent in this species (pers. comm. of the senior author (SK) with Jason Dunlop, Curator of the collections Arachnida and Myriapoda in Berlin Museum). Examination of some specimens assigned to S. hungaricus collected in Iran confirms Dunlop’s observation. This seta was also absent in all examined specimens of S. aegypticus. Seta z 1 was labeled (and symbolised by a circle) on the left side of the illustration of the dorsal shield of S. heterotarsus in Lee (1970). However, the right side of the illustrated shield does not show any seta on the position of z 1, suggesting that z 1 may be absent on that species too. Lee (1970), in the description of the genus, wrote that the z - series has six pairs of setae (z 1 present), an idea that was probably based on the original description of S. hungaricus (Karg 1964) and his own redescription of S. heterotarsus. The most recent work on the family Ologamasidae is a catalogue presented by Castilho et al. (2016). In their diagnosis of the genus Sessiluncus, they stated that: (1) sternal setae st 1 – st 4 aligned longitudinally; but they are not in a longitudinal line in most Sessiluncus species. This is most conspicuous in S. abalaae, S. aegypticus, S. heterotarsus, S. hungaricus, S. indicus and S. oculatus, with the distance between the st 1 – st 1 and st 3 – st 3 pairs markedly shorter than the distance between st 2 – st 2, and (usually) st 4 – st 4 (distance between st 3 – st 3 and st 4 – st 4 is subequal in S. aegypticus); (2) “ exopodal shields near coxae II – III – III divided at median level of coxa III ”; but they are fused in all species into a continuous strip and also fused to the parapodal plate. They also noted that the sternal shield is fused to the endopodal platelets near coxa IV; that is correct for the described species of the genus. However, Lee (1970) stated that free endopodal platelets mediad coxae III – IV were present in “ an unnamed species from Nepal, dep. BM (NH) ”. The same situation was observed in an undescribed species of Sessiluncus collected from western Iran (SK, in prep.). Also, Castilho et al. (2016) did not present any information about modified leg setae or cuticular spurs, the absence of z 1, the lateral crenate projections in the outer margin of the peritrematal shield, the pit-like cuticular structures between setae J 1 – J 2, the male recurved spermatodactyl, and variation in the setation on some of the leg segments. Our revised diagnosis above may therefore be useful. Relationship of the genera of Ologamasidae are highly unstable. Lee (1970) described several subfamilies under Rhodacaridae s. l., including Sessiluncinae as a new subfamily comprising nine genera. On the other hand, Antony (1986) placed Sessiluncus in Gamasiphinae in addition to eight other genera. The two classifications show very little overlap, except for placing Gamasellevans Loots & Ryke, 1967 close to Sessiluncus. Other genera that are similar to Sessiluncus are Gamasellopsis Loots & Ryke, 1966 and Antennolaelaps Womersley, 1956, both placed in Sessiluncinae by Lee (1970). The species placed in Gamasellevans may not form a monophyletic group, with different species showing distinctly different patterns of fusion of the ventral shields and variability in sessile vs. pedunculate pretarsi I. However, all Gamasellevans share a few characters that are different from Sessiluncus: (1) female epigynal shield bearing a subtriangular hyaline margin extending over the sternal shield to the level of setae st 1 or st 2 (vs. anterior hyaline margin in Sessiluncus narrow, never extending to the level of setae st 3); (2) arthrodial process of male chelicera modified to a broad and long membranous process (as long as movable digit or longer) tapering at the end, with fine bristles on the surface (vs. similar structure absent in male chelicera of Sessiluncus, arthrodial process plumose or a small rounded hyaline process bearing short extensions); (3) peritrematal shield barely developed, poststigmatal region of the shield very short (vs. peritrematal shield well developed in Sessiluncus, poststigmatal region of the shield also well developed); (4) exopodal IV well developed, free or fused to ventrianal shield, and capturing the large poststigmatal gland pore (vs. exopodal IV may or may not be developed, free from ventrianal shield, and enlarged poststigmatic gland pore inserted on post-stigmatal region of peritrematal shield in Sessiluncus); and (5) spermatodactyl originating from distal third of the movable digit as a curved or coiled structure, but never strongly recurved (vs. spermadactyl originating on movable digit medially, strongly recurved near the base, then extending straight in Sessiluncus). Although Loots & Ryke (1967) mentioned the fusion line of the podonotal and opisthonotal shield as a generic character for Gamasellevans (also used in Castilho et al. ’ s (2016) key to the genera), the line is not complete or distinct in some species described by Loots & Ryke (1967), such as in G. spermadactylus Loots & Ryke, 1967, G. evansi Loots & Ryke, 1967 and G. reticulatus Loots & Ryke, 1967. In fact, Loots & Ryke (1967) used the presence / absence of the fusion line on the holonotal shield in their species key to separate G. spermadactylus from G. epigynalis Loots & Ryke, 1967. The genera Sessiluncus and Gamasellopsis are quite similar. Both have separate holonotal and ventrianal shields, and the general shape of the ventral idiosomal shields in these mites is largely identical. However, members of Sessiluncus can be distinguished from Gamasellopsis based on the following characters: (1) ambulacrum I sessile (vs. ambulacrum I pedunculate in Gamasellopsis); (2) genu I with 13 setae, including av 1 – av 2 (vs. 12 setae (av 2 absent) in Gamasellopsis); (3) male spermatodactyl strongly recurved (vs. gently curved apically in Gamasellopsis); and (4) poststigmatic section of the peritrematal shield free (vs. relatively broadly abutting exopodal strips laterad acetabula IV in Gamasellopsis) (Loots & Ryke 1966). Loots & Ryke (1966) described Gamasellopsis to accommodate four new species, all of them from Africa. Later, Petrova & Tascaeva (1968) described Gamasellopsis puchus from specimens collected in China. Ma & Zhang (2013) transferred it to the genus Sessiluncus, but we question this because the poststigmatic region of the peritrematal shield in G. puchus is fused to the posterior part of the exopodal strip behind coxa IV. Unfortunately, Petrova & Tascaeva (1968) did not consider pretarsus I: sessile, as in Sessiluncus, or pedunculate, as in Gamasellopsis. Castilho et al. (2016) considered Gamasellopsis puchus as incertae sedis because of the following features: “ it has separate pre-sternal plates, it has two pairs of setae in the opisthogastric soft cuticle rather than one, and it lacks separate endopodal plates III – IV. Its leg chaetotaxy is undescribed. All the described species of Gamasellopsis are from South Africa ”. We agree with Castilho et al. (2016) that the morphology of G. puchus was insufficiently described by Petrova & Tascaeva (1968), but disagree with their reasons to exclude it from Gamasellopsis, because: (1) presternal platelets can be either fused or free in some ologamasid genera, including the genus Sessiluncus; (2) based on Petrova & Tascaeva (1968, figure 6 - 1), there is only one pair of setae on the opisthogastric soft integument in the species, not two (another pair are located on the lateral margins of the dorsal shield extending ventrally), just like all African species of Gamasellopsis; (3) the endopodal platelets between coxae III – IV in females of two species of the African Gamasellopsis are free from the sternal shield (G. curtipilus Loots & Ryke, 1966 and G. longipilus Loots & Ryke, 1966), but they are fused to the sternal shield in two others (G. magoebaensis Loots & Ryke, 1966 and G. vandenbergi Loots & Ryle, 1966). Consequently, we follow Petrova & Tascaeva’s (1968) opinion about the species placement under the genus Gamasellopsis. However, description of the legs of G. puchus, especially the shape of the pretarsus I, would be useful to strengthen its taxonomic position. Antennolaelaps also resembles Sessiluncus by sharing features such as podonotal and opisthonotal shields completely fused, with no visible fusion line, ventrianal shield free posteriorly, sternal shield fused to all endopodal elements, all exopodal elements fused as a continuous strip and joined to parapodal platelet, metapodal platelets incorporated into ventrianal shield, and peritrematal shield free from the exopodal strip. However, in addition to the different shape of the pretarsus I, sessile in Sessiluncus and pedunculate in Antennolaelaps (if present), these two genera can be separated by the following characters: (1) peritreme with deeply crenate outer margin (vs. almost smooth margin in Sessiluncus); (2) genu III with nine setae, including two ventral setae (vs. 8 setae in Sessiluncus, including only one ventral seta); (3) male spermatodactyl gently curved anteriorly (vs. strongly recurved in Sessiluncus); (4) usually a small narrow, free platelet bearing the cribral spicules present behind ventrianal shield in Antennolaelaps (vs. similar platelet absent in Sessiluncus); and (5) a pair of crenate projections on the outer margin of the peritrematal shield at level of coxae II – III which are present in Sessiluncus species, but appear absent in Antennolaelaps. Presumably, based on the similarity of these genera, Domrow (1957) illustrated a specimen as S. heterotarsus, although he was aware that his specimens differ “ in the armature of leg II and in pretarsus I from the illustrations of S. heterotarsus of Vitzthum (1926) ”. Later, Lee (1970) transferred S. heterotarsus sensu Domrow (1957) to the genus Antennolaelaps noting that it might be conspecific with A. testudo Lee, 1970, a new species of Antennolaelaps described in his paper.	en	Kazemi, Shahrooz, Nasr, Abdelrady Korashy, Ramadan, Mahmoud Mohamed, Klompen, Hans (2021): Review of the genus Sessiluncus (Acari: Mesostigmata: Ologamasidae), description of male and redescription of female of Sessiluncus aegypticus, and notes on some morphological characters of the genus. Zootaxa 5061 (2): 271-299, DOI: https://doi.org/10.11646/zootaxa.5061.2.3
039787E32E12FFAEFF7B1E4AFD48F9EA.taxon	diagnosis	Diagnosis (female and male). Dorsal shield with 37 pairs of short setae; glandular opening gd 8 absent, gd 9 present. Presternal platelets free, though abutting sternal shield. Sternal seta st 1 barbed, other sternal setae smooth and shorter than st 1. Ventrianal shield slightly longer than wide. Poststigmatic region of peritrematal shield well developed, wide, obliquely truncate, reaching beyond posterior level of coxa IV. Peritreme straight, extending to anterior level of coxa II. Corniculus without inner tooth. Setae h 1 – h 3 and pc barbed. Lateral transverse ridges connected to deutosternal groove smooth. Movable and fixed digits of chelicera in female with three and four teeth, respectively, and with two and five teeth in male. In female, trochanter II with a small projection posterolateral dorsally; femur III with a small rounded ventral projection; trochanter IV with three anterolateral projections, including one large dorsal projection and two smaller ones ventrally, and one large posterolateral spur-like projection. Male with large spur-like seta av on femur II; seta av on genu and tibia II knob-like, but av on tibia II with a sharp apex; femur III with one large ventral cuticular spur.	en	Kazemi, Shahrooz, Nasr, Abdelrady Korashy, Ramadan, Mahmoud Mohamed, Klompen, Hans (2021): Review of the genus Sessiluncus (Acari: Mesostigmata: Ologamasidae), description of male and redescription of female of Sessiluncus aegypticus, and notes on some morphological characters of the genus. Zootaxa 5061 (2): 271-299, DOI: https://doi.org/10.11646/zootaxa.5061.2.3
039787E32E12FFAEFF7B1E4AFD48F9EA.taxon	description	Description. Adult male (n = 2) (Figures 1 – 8, 10 – 12, 25 – 27, 29, 37) Dorsal idiosoma (Figures 1, 25). Dorsal shield suboval, 473 – 494 long, 279 – 292 wide, anterior region of shield somewhat truncate, with a blunt, somewhat serrate, protrusion on each anterolateral shield corner, flanking either a narrow sclerotised strip anterior to dorsal shield (Figures 1, 3) or a series of narrow discrete platelets (Figure 9). Dorsal shield covering entire dorsal idiosoma and slightly extending ventrally posterolaterally, reticulate throughout, except for anteromedian area between setae j 1 – j 4 and area posterior to seta J 4; with 37 pairs of short setae: j 1 (32 – 35), j 2 (31 – 34) and Z 5 (27 – 29) barbed, z 2, z 4, s 2, s 4 smooth (26 – 29), others 18 – 25 long, mostly smooth; shield with 17 pairs of poroids, including id 1 – id 2, id 4 – id 6, idm 1 – idm 6, idl 1 – idl 4, is 1, idx; in addition to one pair of pcs between idm 2 and idm 3; four pairs of gland pores (gd 1, gd 5, gd 6, gd 9). Ventral idiosoma (Figures 2, 26 – 27). Tritosternal base trapezoidal, short, 22 – 24 long, 22 – 24 wide at base and 9 – 10 wide at apex, sparsely pilose laciniae free, 48 – 51 long. One pair of presternal platelets well sclerotised, free, flanking base of tritosternum. Sternal shield reticulate throughout, 179 – 184 long, 110 – 115 wide, fused to endopodal platelets between coxae I – IV and also fused to continuous exopodal strip anteriorly via the endopodal shield between coxae I – II (area bearing gland pores gvb) and posteriorly via the parapodal shield behind coxae I – IV; male genital opening in anterior region of shield, anterior margin of shield irregularly straight, with two small lateral processes flanking presternal platelets, posterior margin of shield straight; shield with five pairs of setae, st 1 (36 – 38) barbed and longest, st 2 (31 – 33), st 3 (26 – 29), st 4 (27 – 28) and st 5 (25 – 26) smooth, and three pairs of poroids (iv 1 – iv 3); setae st 2 (79 – 85) farther apart than pairs of st 1 (62 – 65), st 3 (68 – 76) and st 4 (65 – 74). Ventrianal shield 202 – 208 long, 207 – 211 wide, reticulate throughout except for smooth posterior area around anal opening, bearing six pairs of opisthogastric setae and circumanals: Jv 1 – Jv 3 smooth (22 – 25), Zv 1 (26 – 28) and Zv 2 (20 – 23) barbed, Zv 3 smooth (26 – 28), para-anal (pa) (22 – 23) and postanal (ps) (24 – 26) setae barbed, with four pairs of poroids, including iv 5 and four pairs of ivo; cribrum narrow, with minute spicules, narrowly extending laterally to level of postanal seta (Figure 27). Opisthogastric soft cuticle with two pairs of setae Jv 4 (20 – 22) and Jv 5 (24 – 25), and three pairs of poroids, idRp, ivo and ivp. Peritrematal shield well developed laterad peritreme, anteriorly fused to dorsal shield and posteriorly free; with two crenate protrusions on lateral margin of shield, at posterior level of coxa II and anterior level of coxa III (Figures 2, 26), bearing one gland pore between crenate projections and one poroid anteriad anterior crenate projection, in addition to one gland pore anterior to the tip of peritreme; poststigmatic shield region slightly wider, obliquely truncate, extending beyond posterior margin of coxa IV, with one poroid and one moderately large gland pore (Figure 26). Peritreme more or less straight, extending to anterior level of coxa II. Gnathosoma (Figures 3 – 4, 29 – 30). Anterior margin of gnathotectum with a median triangular projection, flanked by two shorter acute projections, and sometimes with 1 – 2 denticles in between (Figures 3, 29). Labrum triangular and finely fringed, almost reaching anterior apex of corniculus; with one pair of denticulate paralabra near the base of the labrum; a long directed stylus arising anteriorly from each paralabrum, laying beneath the labrum and extending to anterior labrum tip. Corniculus horn-like; internal malae with a pair of narrow, long and smooth median projections, flanked by oblique, densely fringed margins; subcapitular setae barbed, h 1 – h 3 subequal, 24 – 29 long, longer than pc (19 – 20); deutosternal groove with nine denticulate rows: most anterior row convex to subtriangular, second row straight to slightly concave, both with similar width, third row with markedly larger teeth only medially, fourth to seventh rows with same width and usually bearing minute sparse denticles, eighth row narrower, with distinct teeth, ninth row narrow, as wide as third row, and groove ending by a smooth ridge; with smooth lateral transverse ridges connected to deutosternal groove posteriorly. Second segment of chelicera stout, 152 – 159 long, including fixed digit (72 – 74 long), bearing four teeth, distalmost tooth minute, pilus dentilis short, setiform; movable digit of chelicera almost half as long as second segment of chelicera, 74 – 76 long, with three teeth; dorsal cheliceral seta setiform, smooth; dorsal and antiaxial poroids distinct (Figures 4, 30). Palp length 164 – 172; palp chaetotaxy 2 - 5 - 6 - 14 - 15; setae on trochanter, femur and genu slightly pilose in apical half, setae al on femur and al 1 on genu densely barbed in apical half, d 2 on femur and pl on genu smooth, al 2 on genu apically blade-like, all setae on tibia and tarsus smooth, except al on tibia slightly pilose; palptarsus apotele 3 - tined. Legs (Figures 5 – 8, 10 – 12, 37). Tarsus I with four relatively long subapical setae; ambulacrum I sessile, sheath broadly fused to tarsus and only long enough to contain retracted claw complex (Figure 5); legs II – IV each with three small apicoventral projections on tarsus, and relatively long ambulacral stalk, 34 – 40 long (Figures 10 – 12). Length of legs: I 488 – 507, II 361 – 391, III 301 – 326, IV 409 – 426. Lengths of femora I 103 – 115, II 70 – 76, III 65 – 73, IV 88 – 94; genua I 68 – 72, II 54 – 62, III 41 – 44, IV 56; tibiae I 79 – 83, II 62 – 68, III 41 – 47, IV 62 – 65; tarsi I 138 – 144, II 97 – 100, III 79, IV 103 – 106. Setation of legs I – IV normal for the genus, genu IV with one seta pl (2, 2 / 1, 3 / 0, 1). Leg setae simple, mostly slightly pilose, relatively short to moderately long. Modified setae (Figure 37): av on femur II as a large spur (Figure 6); av on genu and tibia II knob-like, av on tibia apically tapered (Figure 7). Femur III with a large ventral cuticular spur (Figures 8, 37).	en	Kazemi, Shahrooz, Nasr, Abdelrady Korashy, Ramadan, Mahmoud Mohamed, Klompen, Hans (2021): Review of the genus Sessiluncus (Acari: Mesostigmata: Ologamasidae), description of male and redescription of female of Sessiluncus aegypticus, and notes on some morphological characters of the genus. Zootaxa 5061 (2): 271-299, DOI: https://doi.org/10.11646/zootaxa.5061.2.3
039787E32E06FFB6FF7B18A3FC6BFD3E.taxon	description	(Figures 38 – 44)	en	Kazemi, Shahrooz, Nasr, Abdelrady Korashy, Ramadan, Mahmoud Mohamed, Klompen, Hans (2021): Review of the genus Sessiluncus (Acari: Mesostigmata: Ologamasidae), description of male and redescription of female of Sessiluncus aegypticus, and notes on some morphological characters of the genus. Zootaxa 5061 (2): 271-299, DOI: https://doi.org/10.11646/zootaxa.5061.2.3
039787E32E06FFB6FF7B18A3FC6BFD3E.taxon	description	Karg (1964) described S. hungaricus based on female specimens collected in Hungary. Afterward, this species was reported from Israel (Costa & Nevo 1969), Azerbaijan (Bregetova 1977), Slovakia (Fenďa & Ciceková 2009), Iran (Kazemi & Rajaei 2013) and Georgia (Murvanidze et al. 2019). In this study, we examined some female specimens of the species collected in northern Iran, from Golestan and Mazandaran provinces, in addition to the holotype of the species. Despite the generally high-quality original description of S. hungaricus, we found some discrepancies between the original description of this species and the specimens we examined, including the holotype. To address this, we also present an updated diagnosis of this species.	en	Kazemi, Shahrooz, Nasr, Abdelrady Korashy, Ramadan, Mahmoud Mohamed, Klompen, Hans (2021): Review of the genus Sessiluncus (Acari: Mesostigmata: Ologamasidae), description of male and redescription of female of Sessiluncus aegypticus, and notes on some morphological characters of the genus. Zootaxa 5061 (2): 271-299, DOI: https://doi.org/10.11646/zootaxa.5061.2.3
039787E32E06FFB6FF7B18A3FC6BFD3E.taxon	diagnosis	Diagnosis. Dorsal shield with 38 pairs of moderately long and barbed setae; gland pores gd 9 absent, gd 6 and gd 8 located relatively near each other (Figure 38). Presternal plates free. Sternal seta st 1 barbed and longer than smooth setae st 2 – st 4 (Figure 39). Ventrianal shield longer than wide, length / width ratio = 1.17 – 1.25. Poststigmatal extension of peritrematal shield rounded posteriorly, not extending beyond the posterior margin of coxa IV; peritreme straight, and short, not reaching to anterior level of coxa II (Figure 40). Anterior margin of gnathotectum irregularly subtriangular, median projection relatively long, with irregular teeth laterally (Figures 41 – 44). Corniculus without inner tooth; setae h 1 – h 3 and pc barbed, subequal in length; posterior lateral transverse ridges connected to deutosternal groove denticulate. Movable and fixed digits of chelicera in female with three and four teeth, respectively. Genu IV with 10 setae (2, 1 / 1, 3 / 1, 2).	en	Kazemi, Shahrooz, Nasr, Abdelrady Korashy, Ramadan, Mahmoud Mohamed, Klompen, Hans (2021): Review of the genus Sessiluncus (Acari: Mesostigmata: Ologamasidae), description of male and redescription of female of Sessiluncus aegypticus, and notes on some morphological characters of the genus. Zootaxa 5061 (2): 271-299, DOI: https://doi.org/10.11646/zootaxa.5061.2.3
039787E32E06FFB6FF7B18A3FC6BFD3E.taxon	materials_examined	Material examined. Holotype female, collected in litter under oak, Quercus sp. [Fagaceae], bushes, in Tihany, Hungary, 24 July 1962, deposited in Arachnologischen Sammlung des Museums für Naturkunde, Berlin, Germany. Three females collected in soil-litter in Baran Kouh, Gorgan Province, 10 June 2009, one specimen deposited in OSAL, others in ACISTE; three females collected in soil-litter in Gaem Shahr, Mazandaran Province, 10 October 2018, deposited in ACISTE; two females collected in soil-litter in Chalous County, Mazandaran Province, 05 July 2007, deposited in ACISTE. Note. Re-examination of the holotype in addition to a study of the Iranian specimens showed the following discrepancies with the original description of the species: (1) seta z 1 absent (Karg (1964, figure 4) illustrated this seta (labeled r 1) on the dorsal shield); (2) setae h 1 – h 3 and pc lightly barbed (vs. illustrated as smooth in the original description); (3) genu IV with ten setae (with two pl setae), setation of the other leg segments normal for the genus (vs. setation of the leg segments not presented in the original description); and (4) crenate lateral projections present (barely illustrated in the original description). Also, Karg (1964) did not illustrate glandular openings gd 6 and gd 8 or the pit-like cuticular structure, pcs, on the dorsal shield of the species.	en	Kazemi, Shahrooz, Nasr, Abdelrady Korashy, Ramadan, Mahmoud Mohamed, Klompen, Hans (2021): Review of the genus Sessiluncus (Acari: Mesostigmata: Ologamasidae), description of male and redescription of female of Sessiluncus aegypticus, and notes on some morphological characters of the genus. Zootaxa 5061 (2): 271-299, DOI: https://doi.org/10.11646/zootaxa.5061.2.3
039787E32E01FFB7FF7B1B76FA32FF1A.taxon	description	(Figures 45 – 56)	en	Kazemi, Shahrooz, Nasr, Abdelrady Korashy, Ramadan, Mahmoud Mohamed, Klompen, Hans (2021): Review of the genus Sessiluncus (Acari: Mesostigmata: Ologamasidae), description of male and redescription of female of Sessiluncus aegypticus, and notes on some morphological characters of the genus. Zootaxa 5061 (2): 271-299, DOI: https://doi.org/10.11646/zootaxa.5061.2.3
039787E32E01FFB7FF7B1B76FA32FF1A.taxon	diagnosis	Diagnosis (female). Dorsal shield with 35 (36?) pairs of setae, heterogeneous in shape and size; elongate setae slightly flattened near the tip (Figure 46); length ratio of Z 5 / J 5 = 7 – 8.5 (Figure 52); glandular opening gd 8 absent, gd 9 present (Figures 45, 52). Presternal plates free. Sternal shield sculptured with large suboval ornamentations; sternal setae subequal in length, lightly barbed (Figures 47, 52). Seta st 5 finely barbed. Ventrianal shield markedly wider than long, length / width ratio = 0.8 (Figure 52). Poststigmatic region of peritrematal shield well developed, wide, obliquely truncate, extending beyond coxa IV (Figures 49, 52). Peritreme straight, extending to anterior level of coxa II (Figure 52). Anterior margin of gnathotectum with a widely triangular, short medial projection, flanked by one pair of short lateral prongs (Figure 53). Corniculus with an inner tooth (Figure 55); setae h 1 – h 3 and pc barbed; posterior lateral transverse ridges connected to deutosternal groove smooth (Figure 54). Movable and fixed digits of chelicera with three teeth (Figure 56). Tibia IV with 8 setae (1, 1 / 1, 3 / 1, 1). Trochanter IV with one large hatchet-like projection and one small protrusion dorsally (Figures 49 – 50 a, b); femora III – IV each with one finger-like projection (Figures 49, 50 a, 51); ventral seta on genu III inserted on a small protrusion (Figure 51).	en	Kazemi, Shahrooz, Nasr, Abdelrady Korashy, Ramadan, Mahmoud Mohamed, Klompen, Hans (2021): Review of the genus Sessiluncus (Acari: Mesostigmata: Ologamasidae), description of male and redescription of female of Sessiluncus aegypticus, and notes on some morphological characters of the genus. Zootaxa 5061 (2): 271-299, DOI: https://doi.org/10.11646/zootaxa.5061.2.3
039787E32E01FFB7FF7B1B76FA32FF1A.taxon	materials_examined	Material examined. One female specimen, Panama (no further collection information), OSAL 0017119. Note. This species was originally described from Hawai (Vitzthum 1935), and was subsequently reported from India (Bhattacharyya 1965), and now from Panama. These geographical data are unusual, suggesting a pantropical distribution. The Panama record would also make S. oculatus the first Sessiluncus species reported from the Americas. The original description of the species and its redescription show fewer than 30 pairs of setae on the adult male and female dorsal shield. However, examination of the specimen at hand indicated that the species has 6 – 7 additional pairs of short setae on the marginal areas of the shield (Figure 52). In his complementary description of S. oculatus, Bhattacharyya (1965) illustrated the exopodal strips fused to the ventrianal shield in both sexes (figures 2 B, 3 B). This does not match with the original description of the species or our observation on the Panama specimen.	en	Kazemi, Shahrooz, Nasr, Abdelrady Korashy, Ramadan, Mahmoud Mohamed, Klompen, Hans (2021): Review of the genus Sessiluncus (Acari: Mesostigmata: Ologamasidae), description of male and redescription of female of Sessiluncus aegypticus, and notes on some morphological characters of the genus. Zootaxa 5061 (2): 271-299, DOI: https://doi.org/10.11646/zootaxa.5061.2.3
