Ischnothyreus fobor, Kranz-Baltensperger, Yvonne, 2011

Kranz-Baltensperger, Yvonne, 2011, The oonopid spider genus Ischnothyreus in Borneo (Oonopidae, Araneae), Zootaxa 2939, pp. 1-49 : 27-46

Ischnothyreus fobor sp. nov.

( Figs 20–21 , 35 )

Type material: Holotype: male (PBI_OON 00016082), MALAYSIA: Sabah: Danum Valley Field Centre, 6.– 16.V.1991, leg. C.L. & P.R. Deeleman, RMNH. Paratypes: 2 males & 2 females (PBI_OON 00032229), collected together with holotype, RMNH.

Additional material examined: 2 males (PBI_OON 00031469), MALAYSIA: Sabah: Kinabalu National Park, 1550m, 21.–27.VII.1980, leg. C.L. & P.R. Deeleman ( RMNH). 1 male (PBI_OON 00032231), Bru-88/12. BRU- NEI DARUSSALAM: Brunei-Muara District: près du pont sur le ruisseau Sungai Lubang Barus , route venant de Tutong, 33km de Bandar Seri Begawan, prélèvement de sol au pied de deux grands arbres proches des habitations, env. 20m (translated: close to bridge over Sungai Lubang Barus river, route from Tutong, 33 km from Bandar Seri Begawan, soil extraction at base of two large trees close to habitations, ca. 20m); 16.XI.1988; leg. B. Hauser (Berlese à Seri Begawan) ( MHNG), 1 female (PBI_OON 00015355), Bru-88/33. BRUNEI DARUSSALAM: Belait District: Labi Hills Forest Reserve, Teraja, 42km S de Sungai Liang (12km au Sud de Labi), environs de Rumah Panjang, forêt primaire (translated: Labi Hills Forest Reserve, Teraja, 42km south of Sungai Liang (12km south of Labi), proximity of Rumah Panjang), mixed dipterocarp forest, 40m; 22.XI.1988, leg. C. Lienhard ( MHNG).

Etymology: The specific name, a noun in apposition, is an abbreviation of "found in Borneo".

Diagnosis: The male of I. fobor can be recognized by the palpal bulb with its extremely long and thin embolus ( Fig. 20 E–F). The female genital area is characterized by a small strongly winding tube running posteriorly ( Fig. 21 F–G).

Description: Male (holotype). Total length 1.66 mm. Carapace: domed in lateral view, fovea present, lateral margin slightly rebordered. Clypeus: curved downwards in frontal view. Eyes: ALE touching. Sternum: setae abundant. Mouthparts: chelicerae slightly divergent, without prominent process at base of fangs, fang groove with few small and one larger denticles ( Fig. 20 G). Anterior margin of labium indented at middle. Anteromedian tip of endites with one strong, tooth-like projection (stp) ( Fig. 20 D). Abdomen: scutum extending far dorsal of pedicel. Dorsal scutum covering 1/2 to 3/4 of abdomen, fused to epigastric scutum. Epigastric and postepigastric scutum short, almost rectangular, covering about 2/3 of abdominal length. Spinneret scutum present, incomplete ring, with fringe of needle-like setae. Legs: spine formula: femora: I p0-1-1; II p0-0-1; tibiae: I, II p2-1-1; r2-1-1; metatarsi: I, II p1-1-0; r1-1-0. Genitalia: Palp strongly sclerotized, proximal segments dark brown, trochanter with large ventral projection (vp) ( Fig. 20 D–F), femur normal size, patella shorter than femur, not enlarged, cymbium dark brown, fused with bulb, bulb dark brown, more than two times as long as cymbium, stout, tapering apically, with ventral protuberance (vpr) and lobe (l), embolus (e) very long and filamentous, originating between several membranous outgrowths (mo) ( Fig. 20 E–F).

Female (paratype). Total length 1.68 mm. As in male except as noted. Carapace: without any pattern, broadly oval in dorsal view, pars cephalica strongly elevated in lateral view. Clypeus: straight in frontal view. Eyes: ALE separated by less than their radius. Mouthparts: labium not fused to sternum, anterior margin not indented at middle. Endites unmodified. Femur of female palp with three ventral spines, tibia with three trichobothria. Abdomen: dorsal scutum covering about 1/2 of abdomen, not fused to epigastric scutum. Postepigastric scutum widely hexagonal, covering about 1/3 of the abdominal length, with short posteriorly directed lateral apodemes (a) ( Fig. 21 F). Dense patch of setae anterior to spinnerets present. Legs: spine formula: femora: I p0-1-1; r0-1-1; II p0-0-1; r0-0-1; tibiae: I, II p2-1-1; r2-1-1; metatarsi: I, II p1-1-0; r1-1-0. Genitalia: simple, in the middle of the anterior margin of the postepigastric scutum starts a winding tube (wt), running posteriorly, ending in globlet-like structure (gls) ( Fig. 21 F–G).

Distribution: Sabah and Brunei ( Fig. 35 ).

Ischnothyreus hooki sp. nov. ( Figs 22–23 , 35 )

Type material: Holotype: male (PBI_OON 00031692), INDONESIA: East Kalimantan : Tenggarong, light forest, leaflitter, 4.VIII.1980, coll. Deeleman, RMNH. Paratypes: 1 male (PBI_OON 00031363), INDONESIA: East Kalimantan : Sepaku, 40km NNW from Balikpapan, degraded primary forest, 2.VIII.1980, coll. Deeleman, RMNH. 2 females (PBI_OON 00031769), INDONESIA: East Kalimantan : Sepaku, 40km NNW of Balikpapan, primary forest, dry period, 21./ 22.VII.1982, coll. Deeleman, RMNH.

Additional material examined: 1 female (PBI_OON 00031777), INDONESIA: East Kalimantan : Sepaku, 40km NNW of Balikpapan, degraded rainforest, litter, 2.–5.VIII.1980, coll. Deeleman ( RMNH). 1 male (PBI_OON 00031628), INDONESIA: East Kalimantan : Sungai Wain Protection Forest, ca. 15 km N of Balikpapan (1°08’36”S, 116°50’59”E), 80m, secondary forest adjacent to primary forest, 5./ 7.X.2008, leg. P. Schwendinger ( MHNG).

Etymology: The specific name is derived from Captain Hook from the novel Peter Pan, written by James M. Barrie, and refers to the similarity of the distal part of the male palp with the left arm of Captain Hook.

Diagnosis: The male of I. hooki can be recognized by the hook-like embolus ( Fig. 22 G–J). With its strongly winding tube, the female genital area of I. hooki is similar to I. fobor , but the winding tube in I. hooki is larger.

Description: Male (holotype). Total length 1.33 mm. Carapace: broadly oval in dorsal view. Clypeus: curved downwards in frontal view, low, ALE separated from edge of carapace by less than their radius. Eyes: PLE circular, posterior eye row straight from above, procurved from front. Sternum: setae abundant. Mouthparts: chelicerae without prominent process at base of fangs. Labium triangular. Anteromedian tip of endites with one strong, toothlike projection (stp) ( Fig. 22 B, C, F). Abdomen: scutum extending far dorsal of pedicel. Legs: spine formula: femora: I p0-1-1; r0-0-1; II v0-0-2; tibiae: I, II v4-2 -2; metatarsi: I, II v2-2 -0. Genitalia: Sperm pore situated in front of anterior spiracles. Palps strongly sclerotized, proximal segments brown, trochanter with ventral projection, patella about as long as femur, not enlarged, cymbium brown, fused with bulb, bulb brown, more than two times as long as cymbium, stout, tapering apically, with ventral protuberance (vpr) ( Fig. 22 H, J) and lobe (l) ( Fig. 22 . G, I), distal part with ear-like outgrowth (elo) prolaterally ( Fig. 22 H, J), embolus (e) short hook ( Fig. 22 G, I, J).

Female (paratype). Total length 1.80 mm. As in male except as noted. Carapace: without any pattern. Eyes: posterior eye row procurved from above. Mouthparts: endites unmodified. Femur of female palp with four ventral spines, tibia with three trichobothria. Abdomen: scutum not extending far dorsal of pedicel. Dorsal scutum covering less than 1/2 of abdomen, less than 1/4 abdomen width, not fused to epigastric scutum. Postepigastric scutum widely hexagonal, only around epigastric furrow, with short posteriorly directed lateral apodemes (a) ( Fig. 23 E). Dense patch of setae anterior to spinnerets present. Legs: spine formula: femora: I p0-2-1; r0-0-1; II p0-0-2; tibiae: I, II p2-1-1; r2-1-1; metatarsi: I, II p1-1-0; r1-1-0. Genitalia: the posterior margin of the epigastric scutum is lined with numerous needle-like setae. In the middle of the postepigastric scutum is a strongly winding tube (wt) ( Fig. 23 E–H) visible, which runs posteriorly.

Distribution: East Kalimantan ( Fig. 35 ).

Remarks: Male and female of this species were not collected together. However, since the somatic morphology is very similar they are tentatively considered as conspecific.

Ischnothyreus jojo sp. nov. ( Figs 24–25 , 35 )

Type material: Holotype: male (PBI_OON 00032184), INDONESIA: Central Kalimantan : Kaharian, 2°02'S, 113°40'E, 2.–16.IX.1985, swampy primary forest, leaflitter, leg. Suh. Djojosudharmo, coll. Deeleman, RMNH. Paratypes: 3 females (PBI_OON32181), collected together with holotype, RMNH.

Additional material examined: 2 females (PBI_OON 00031468), INDONESIA: Central Kalimantan : Tumbang Tahai, 2°02'S, 113°35'E, primary marshy forest, 2.–13.IX.1985, coll. Deeleman, leg. Suh. Djojosudharmo ( RMNH).

Etymology: The specific name is an arbitrary combination of letters.

Diagnosis: The male of I. jojo can be recognized by the plate-like basal process and the saw-like extension at the base of the cheliceral fang ( Fig. 24 E). The female genital area is characterized by the posteriorly running, strongly winding tube, anteriorly covered by a u-shaped, sclerotized structure ( Fig. 25 E–G).

Description: Male (holotype). Total length 1.76 mm. Clypeus: low, ALE separated from edge of carapace by less than their radius. Eyes: PME largest. Mouthparts: chelicerae slightly divergent, process at base of fangs platelike (pbp), with inwards pointing hook distally, and with a saw-shaped extension (sse), fang groove with few small and one larger denticles ( Fig. 24 D–E). Anterior margin of labium indented at middle. Anteromedian tip of endites with one strong, tooth-like projection (stp) ( Fig. 24 B). Abdomen: epigastric and postepigastric scutum fused. Postepigastric scutum long, almost rectangular, covering about 3/4 of abdominal length. Legs: spine formula: femora: I p0-1-1; r0-0-2; II p0-0-1; r0-0-1; tibiae: I, II p2-1-1; r2-1-1; metatarsi: I, II p1-1-0; r1-1-0. Genitalia: Palp strongly sclerotized, proximal segments brown, trochanter with small ventral projection (vp) ( Fig. 24 F), femur normal size, patella about as long as femur, not enlarged, cymbium brown, fused with bulb, bulb brown, 1 to 1.5 times as long as cymbium, stout, tapering apically, with ventral protuberance (vpr) and lobe (l), apex of bulb roundish with small pointed apophyses (spa), embolus not discernible ( Fig. 24 F–G).

Female (paratype). Total length 2.13 mm. As in male except as noted. Carapace: without any pattern, broadly oval in dorsal view, pars cephalica slightly elevated in lateral view. Clypeus: curved downwards in frontal view. Eyes: posterior eye row straight from above. Sternum: setae abundant. Mouthparts: chelicerae straight; without modification Labium triangular. Endites unmodified. Femur of female palp with four ventral spines, tibia with three trichobothria. Abdomen: dorsal scutum covering less than 1/2 of abdomen, less than 1/4 abdomen width, not fused to epigastric scutum. Epigastric scutum slightly protruding. Postepigastric scutum widely hexagonal, only around epigastric furrow, not fused to epigastric scutum, with short posteriorly directed lateral apodemes (a) ( Fig. 25 E–G). Dense patch of setae anterior to spinnerets present. Legs: spine formula: femora: I p0-1-2; r0-0-2; II p0-0- 1; r0-0-1; tibiae: I, II p2-1-1; r2-1-1; metatarsi: I, II p1-1-0; r1-1-0. Genitalia: the posterior margin of the epigastric scutum is lined with numerous, long, needle-like setae. The epigastric furrow is narrow. The margin of the postepigastric scutum is slightly thickened. In its middle starts a dark thin, winding tube (wt) running posteriorly. The tube is covered ventrally by a sclerotized u-shaped structure (uss). On both sides of the tube are small, curved sclerotized extensions (cse) ( Fig. 25 E–G) visible.

Distribution: Central Kalimantan ( Fig. 35 ).

Ischnothyreus kalimantan sp. nov. ( Figs 26–27 , 35 )

Type material: Holotype: male (PBI_OON 00032180), INDONESIA: Central Kalimantan : Kaharian, 2°02'S, 113°40'E, 2.–16.IX.1985, swampy primary forest, leaflitter, leg. Suh. Djojosudharmo, coll. Deeleman, RMNH. Paratypes: 2 males & 5 females (PBI_OON 00032183), collected with holotype, RMNH.

Etymology: The specific name is a noun in apposition and refers to the Indonesian name of Borneo, the island where this species was collected.

Diagnosis: The male of I. kalimantan can be recognized by the distal part of the palpal bulb, which is blunt and entirely surrounded by a translucent membrane ( Fig. 26 F–G). The female genital area is protruding, the strongly winding tube ends in a rather large sluice, which is folded underneath itself ( Fig. 27 F–H).

Description: Male (holotype). Total length 1.79 mm. Eyes: all subequal. Sternum: as long as wide. Mouthparts: chelicerae straight, fang groove with few small and one larger denticles. Anteriorly directed, slightly sclerotized process (ssp) at base of fangs ( Fig. 26 E). Labium triangular, anterior margin indented at middle. Anteromedian tip of endites with one strong, tooth-like projection (stp) ( Fig. 26 B). Abdomen: scutum extending far dorsal of pedicel. Dorsal scutum orange-brown, covering 1/2 to 3/4 of abdomen width. Epigastric and postepigastric scutum fused, postepigastric scutum short, almost rectangular, covering about 2/3 of abdominal length. Legs: spine formula: femora: I p0-1-1; r0-1-2; II p0-0-1; r0-1-2; tibiae: I, II p2-1-1; r2-1-1; metatarsi: I, II p1-1-0; r1-1-0; Genitalia: Palp strongly sclerotized, proximal segments brown, trochanter with ventral projection (vp) ( Fig. 26 F), femur normal size, patella longer than femur, not enlarged, cymbium brown, fused with bulb, bulb brown, 1 to 1.5 times as long as cymbium, stout, tapering apically, with ventral protuberance (vpr) and lobe (l), distal part of bulb blunt, with several small pointed apophyses (spa), entirely surrounded by translucent membrane (m) ( Fig. 26 F–G).

Female (paratype). Total length 1.88 mm. As in male except as noted. Carapace: orange-brown, without any pattern, broadly oval in dorsal view, pars cephalica slightly elevated in lateral view, fovea present. Endites unmodified. Femur of female palp with five ventral spines, tibia with three trichobothria. Abdomen: scutum not extending far dorsal of pedicel. Dorsal scutum covering about 1/2 of abdomen. Epigastric scutum strongly protruding. Postepigastric scutum widely hexagonal, only around epigastric furrow, not fused to epigastric scutum, with short, posteriorly directed lateral apodemes (a) ( Fig. 27 F–H). Dense patch of setae anterior to spinnerets present. Legs: spine formula: femora: I p0-1-1; r0-1-2; II p0-0-1; r0-1-2; tibiae: I, II p2-1-1; r2-1-1; metatarsi: I, II p1-1-0; r1-1-0. Genitalia: the posterior margin of the epigastric scutum is lined with numerous, long, needle-like setae. The epigastric furrow is wide. The margin of the postepigastric scutum is slightly thickened. In its middle starts a dark, thin, strongly winding tube (wt) running posteriorly, prolonged with a translucent sluice (ts), distally folded underneath itself ( Fig. 27 F–H). The sluice is ventrally lined with numerous, needle-like setae on both sides.

Distribution: Central Kalimantan ( Fig. 35 ).

Ischnothyreus matang sp. nov. ( Figs 28–29 , 35 )

Type material: Holotype: male (PBI_OON 00031470), MALAYSIA: Sarawak: Matang , 122m, leaflitter, 4.IV.1985, coll. Deeleman, leg. C.L. & P.R. Deeleman, RMNH. Paratypes: 1 female (PBI_OON 00032185), collected together with holotype, RMNH. 1 female (PBI_OON 00016081), MALAYSIA: Sarawak: Santubong, 20km N of Kuching, Camp Permai, 1°46'N, 110°19'E, 10m, 5.–10.VIII.2003, leg. A. Schulz (winkler-extraction), AS /03-2, MHNG.

Etymology: The specific name is a noun in apposition taken from the type locality.

Diagnosis: The male of I. matang can be recognized by the large ventral lobe and the collar-like membrane on the palpal bulb ( Fig. 28 E–F). The female genital area shows a strongly winding tube, ending in a goblet-like structure ( Fig. 29 D–E).

Description: Male (holotype). Total length 1.59 mm. Fovea present. Clypeus: low, ALE separated from edge of carapace by less than their radius. Sternum: wider than long. Mouthparts: chelicerae slightly divergent, without prominent process at base of fangs, fang groove with few denticles. Anteromedian tip of endites with one strong, tooth-like projection (stp) ( Fig. 28 D). Abdomen: scutum extending far dorsal of pedicel. Dorsal scutum covering less than 1/2 of abdomen, more than 1/2 to most of abdomen width, fused to epigastric scutum. Epigastric scutum and postepigastric scutum fused. Legs: spine formula: I p0-1-2; r0-0-1; tibiae: I p2-1-1; r2-1-1; metatarsi: I p1-1-0; r1-1-0. Genitalia: Sperm pore situated in front of anterior spiracles. Palp strongly sclerotized, proximal segments brown, trochanter with large ventral projection (vp) ( Fig. 28 E), patella about as long as femur, not enlarged, cymbium brown, fused with bulb, bulb brown, more than two times as long as cymbium, stout, tapering apically, with double ventral protuberance (vpr) and lobe (l), distal part with small, spine-like apophysis (sa) dorsally. Collar-like membrane (m) on retrolateral side, embolus (e) slightly curved ( Fig. 28 E–F).

Female (paratype). Total length 1.90 mm. As in male except as noted. Carapace: without any pattern, broadly oval in dorsal view. Fovea absent. Sternum: longer than wide, setae abundant. Labium triangular, anterior margin indented at middle. Endites unmodified. Abdomen: Dorsal scutum less than 1/4 abdomen width. Epigastric scutum strongly protruding. Postepigastric scutum widely hexagonal, covering about 1/3 of the abdominal length, not fused to epigastric scutum, with short posteriorly directed lateral apodemes (a) ( Fig. 29 D). Spinneret scutum with a fringe of needle-like setae. Dense patch of setae anterior to spinnerets present. Legs: spine formula: femora: I p0- 1-2; r0-0-1; II p0-0-1; r0-0-1; tibiae: I, II p2-1-1; r2-1-1; metatarsi: I, II p1-1-0; r1-1-0. Genitalia: the posterior margin of the epigastric scutum is lined with numerous, long, needle-like setae. The epigastric furrow is rather wide. The margin of the postepigastric scutum is thickened. In its middle starts a thin, strongly winding tube (wt), ending straight in elongated, narrow, goblet-like structure (gls), which is protruding from the scutum ( Fig 29 D–E).

Distribution: Sarawak ( Fig. 35 ).

Remark: Since only one male specimen (the holotype) and two female specimens are currently available, a more accurate examination (preparation of the chelicerae, for example) was not possible; further examinations should be done as soon as more specimens become available.

Ischnothyreus mulumi sp. nov. ( Figs 30–31 , 35 )

Type material: Holotype: male (PBI_OON 00012470), AS /03-7. MALAYSIA: Sarawak: Mulu, National Park, 100km SEE of Miri, 4°00'N, 114°49'E, 200m, 19.–24.VIII.2003, leg. A. Schulz (winkler-extraction), MHNG. Paratypes: 4 females (PBI_OON 00032196), same data as holotype, MHNG.

Additional material examined: 1 male & 1 female (PBI_OON 00036304), BRUNEI DARUSSALAM: Temburong District: Ashton Trail near Kuala Belalong Field Studies Centre, 21km SSW Bangar, 04°32.513'N, 115°09.300'E, 100–150m, primary mixed dipterocarp forest, sifting leaf litter, 1.X.2009, C. Griswold & N. Chousou Polydouri UT004, CASENT 9036044 ( CAS). 2 females (PBI_OON 00036326), same data as PBI_OON 0 0 0 36304 except miniwinkler extraction of concentrated leaf litter, 3.X.2009 ( CAS). 1 male (PBI_OON 00036335), same data as PBI_OON 0 0 0 36304 except 4–9.X.2009 ( CAS). 1 female (PBI_OON 00036333), same data as PBI_OON 0 0 0 36304 ( CAS). 1 male (PBI_OON 00036325), same data as PBI_OON 0 0 0 36326 ( CAS). 1 female (PBI_OON 00035260), same data as PBI_OON 0 0 0 36326 ( CAS). 1 female (PBI_OON 00031652), INDO- NESIA: East Kalimantan : Berau Distr., Hutan Wisata Sei Tangap, ca. 8 km W of Tanjungredeb (2°08’04”N, 117°24’39”E), 30m (primary forest), 2.X.2008, leg. P. Schwendinger ( MHNG). 1 female (PBI_OON 00031644), INDONESIA: East Kalimantan : Berau Distr., Hutan Mayang Mangurai, ca. 15 km SW of Tanjungredeb (2°06’13”N, 117°24’05”E), 20m (secondary forest), 30.IX.2008, leg. P. Schwendinger ( MHNG).

Etymology: The specific name is a noun in apposition taken from the type locality.

Diagnosis: The male of I. mulumi can easily be recognized by the unusual, crown-shaped terminal part of the bulb, with a beak-like apophysis on the ventral side ( Fig. 30 H–J). The female genital area is characterized by the strongly winding tube, ending posteriorly in a circle, surrounded by numerous short setae ( Fig. 31 G–J).

Description: Male (holotype). Total length 1.53 mm. Carapace: orange-brown, broadly oval in dorsal view, domed in lateral view, surface of elevated portion of pars cephalica strongly reticulate, sides strongly reticulate. Sternum: as long as wide, setae abundant. Mouthparts: chelicerae with anteriorly directed process (bp) at base of fangs and brush (b) on retromargin ( Fig. 30 G), fang groove with few denticles. Anterior margin of labium indented at middle. Anteromedian tip of endites with one strong, tooth-like projection (stp) ( Fig. 30 E). Abdomen: book lung covers large, elliptical. Pedicel tube medium, scutum extending far dorsal of pedicel. Dorsal scutum strongly sclerotized, orange, anteriorly and posteriorly darkened, covering full length of abdomen, middle surface and sides striated. Epigastric and postepigastric scutum strongly sclerotized, fused, postepigastric scutum long, almost rectangular, covering about 3/4 of abdominal length. Spinneret scutum with fringe of long setae. Legs: spine formula: femora: I p0-1-1; r0-1-0; II p0-0-1; tibiae: I, II p2-1-1; r2-1-1; metatarsi: I, II p1-1-0; r1-1-0. Genitalia: Palp strongly sclerotized, proximal segments brown, trochanter with ventral projection (vp) ( Fig. 30 E), patella about as long as femur, not enlarged, cymbium brown, fused with bulb, bulb brown, more than twice as long as cymbium, stout, tapering apically, with ventral protuberance (vpr) and lobe (l) ( Fig. 30 H), end of bulb enlarged, ribbed (ri), crown-shaped. Membranous, beak-shaped apophysis (bsa) and collar-like membrane (clm) ventrally ( Fig. 30 I–J).

Female (paratype). Total length 1.66 mm. As in male except as noted. Carapace: without any pattern, pars cephalica strongly elevated in lateral view. Sternum: longer than wide. Mouthparts: without basal process and brush. Labium anterior margin not indented at middle. Endites unmodified. Femur of female palp with three ventral spines. Abdomen: epigastric scutum slightly protruding (arrow) ( Fig. 31 C). Postepigastric scutum widely hexagonal, covering about 1/3 of the abdominal length, not fused to epigastric scutum, with short, curved, posteriorly directed lateral apodemes (a) ( Fig. 31 F). Dense patch of setae anterior to spinnerets present. Legs: spine formula: femora: I p0-1-1; r0-1-0; II p0-0-1; v0-0-1; tibiae: I, II p2-1-1; r2-1-1; metatarsi: I, II p1-1-0; r1-1-0. Genitalia: the posterior margin of the epigastric scutum is lined with numerous needle-like setae. The margin of the postepigastric scutum is thickened. At its middle starts a dark, thin, strongly winding tube running backwards (wt), ending in a dark, half-circle (hc), surrounded by numerous setae ( Fig. 31 G–J).

Distribution: Sarawak, Brunei and East Kalimantan ( Fig. 35 ).

Remark: The material collected in Brunei, 2009, is kept in 97% ethanol. The specimens are very dark.

Ischnothyreus rex sp. nov. ( Figs 32–33 , 35 )

Type material: Holotype: male (PBI_OON 00016064), MALAYSIA: Sabah: Kinabalu National Park, Power Station, 1960m, 4.V.1991, leg. C.L. & P.R. Deeleman, RMNH. Paratype: female (PBI_OON 00016065), collected with holotype, RMNH.

Etymology: The specific epithet is a noun in apposition meaning “king” in Latin. It refers to the crown-shaped process on the base of the male cheliceral fang.

Diagnosis: Very large species. The male of I. rex resembles the male of I. fobor in having a very long and thin embolus ( Fig. 32 I–J), but can easily be distinguished from the latter by the crown-shaped basal process on the cheliceral fang ( Fig. 32 F–H). The female of I. rex resembles the female of I. flippi in having a sclerotized y-shaped structure in the genital area, but can be distinguished from the latter by the presence of a dark circle, which seems to be a prolongation of the y-shaped structure ( Fig. 33 G–I).

Description: Male (holotype). Total length 2.94 mm. Carapace: orange-brown, slightly elevated in lateral view, surface and sides of elevated portion of pars cephalica finely reticulate, fovea present, lateral margin rebordered. Sternum: longer than wide, pale orange, uniform, not fused to carapace, surface smooth, setae abundant. Mouthparts: chelicerae slightly divergent, with a prominent, crown-shaped process (csp) at the base of the fangs ( Fig. 32 F–H). Anteromedian tip of endites with one strong, tooth-like projection (stp) ( Fig. 32 E). Abdomen: book lung covers large, elliptical (blc) ( Fig. 32 C). Scutum extending far dorsal of pedicel. Dorsal scutum yellow-brown, fused to epigastric scutum. Spinneret scutum present, incomplete ring, with fringe of long setae. Colulus present. Legs: spine formula: femora: I p0-1-1; II p0-1-0; tibiae: I, II p2-1-1; r2-1-1; metatarsi: I, II p1-1-0; r1-1-0. Each tibia with three trichobothria, each metatarsus with one trichobothrium. Genitalia: Palp strongly sclerotized, proximal segments almost black, trochanter with ventral projection (vp) ( Fig. 32 E), patella about as long as femur, not enlarged, cymbium almost black, fused with bulb, bulb almost black, 1 to 1.5 times as long as cymbium, stout, tapering apically, with ventral protuberance (vpr) and lobe (l), embolus (e) extremely long and thin, filamentous, base of embolus with several membranous outgrowths (mo) ( Fig. 32 I–J).

Female (paratype). Total length 3.62 mm. As in male except as noted. Carapace: without any pattern, broadly oval in dorsal view. Mouthparts: chelicerae without prominent basal process. Anteromedian tip of endites unmodified. Femur of female palp with six ventral spines, tibia with three trichobothria, end of tarsus finger-like ( Fig. 33 F, arrow). Abdomen: pedicel tube medium. Dorsal scutum covering less than 1/2 of abdomen, not fused to epigastric scutum. Epigastric scutum slightly protruding, with small lateral sclerites (sls) ( Fig. 33 E). Postepigastric scutum widely hexagonal, only around epigastric furrow, not fused to epigastric scutum, with short, posteriorly directed lateral apodemes (a) ( Fig. 33 E, G–I). Legs: spine formula: femora: I p0-1-1; r0-0-2; II p0-0-1; tibiae: I, II p2-1-1; r2-1-1; metatarsi: I, II p1-1-0; r1-1-0. Genitalia: the posterior margin of the epigastric scutum is lined with numerous needle-like setae. The margin of the postepigastric scutum is thickened. At its middle is a y-shaped, sclerotized structure visible (yss), whose posterior part leads to a tube. After overlapping itself, the tube runs as a circle, surrounds the y-shaped structure and finally leads to the strongly winding tube (wt) ( Fig. 33 E, G–I).

Distribution: Sabah ( Fig. 35 ).

Ischnothyreus serapi sp. nov. ( Figs 34 , 35 )

Type material: Holotype: male (PBI_OON 00032200), MALAYSIA: Sarawak: route Kuching– Matang , Gunung Serapi , prélèvement du sol dans la forêt le long de la route vers la station TV (translated: soil extraction in forest along street in direction of television station), 670m, 9.XII.1987, leg. B. Hauser (Berlese à Kuching), Sar-87/64, MHNG. Paratype: male (PBI_OON 00016218), same data as for holotype, MHNG.

Etymology: The specific name is a noun in apposition taken from the type locality.

Diagnosis: The male of I. serapi can be recognized by the anvil-shaped distal part of the palpal bulb ( Fig. 34 F–H).

Description: Male (holotype). Total length 1.15 mm. Carapace: whole carapace strongly reticulate. Eyes: all subequal, PLE circular. Mouthparts: chelicerae, endites and labium yellow. Chelicerae with small process (sbp) at base of the fangs. Brush (b) on retromargin near the basal process ( Fig. 34 E). Anteromedian tip of endites with one strong, tooth-like projection (stp) ( Fig. 34 B). Abdomen: dorsal scutum strongly sclerotized, covering full length of abdomen, more than 1/2 to most of abdomen width, middle surface striated, sides striated. Epigastric and postepigastric scutum strongly sclerotized, fused. Legs: spine formula: femora: I p0-1-1; r0-0-1; II p0-0-1; tibiae: I, II p2- 1-1; r2-1-1; metatarsi: I, II p1-1-0; r1-1-0. Genitalia: Palp strongly sclerotized, proximal segments brown, trochanter normal size, with ventral projection (vp), femur normal size, patella about as long as femur, not enlarged, cymbium brown, fused with bulb, bulb brown, more than two times as long as cymbium, stout, tapering apically, with ventral protuberance (vpr) and lobe (l), distal part of bulb laterally enlarged, anvil-shaped, ribbed (ri), with crown-shaped basis (csb) and small, pointed apophyses distally (pa) ( Fig. 34 F–H). Embolus not clearly discernible.

Female: Unknown.

Distribution: Sarawak ( Fig. 35 ).

Figures

FIGURE 20. Ischnothyreus fobor sp. nov. male. A, habitus, dorsal view; B, habitus, ventral view; C, carapace, dorsal view; D, carapace, ventral view; E, F, left palp, prolateral view; G, left chelicera, anterior view. vp, ventral projection; stp, strong-toothlike projection; vpr, ventral protuberance; l, lobe; e, embolus; mo, membranous outgrowth. Scale bars A, B = 1 mm; C, D = 0.5 mm; E, F, G = 0.1 mm.

FIGURE 21. Ischnothyreus fobor sp. nov. female. A, habitus, dorsal view; B, habitus, lateral view; C, carapace, dorsal view; D, carapace, ventral view; E, carapace, frontal view; F, genital area, ventral view, G, genital area, dorsal view. a, apodeme; wt, winding tube; gls, goblet-like structure. Scale bars A, B = 1 mm; C, D, E = 0.5 mm; F, G = 0.1 mm.

FIGURE 22. Ischnothyreus hooki sp. nov. male. A, habitus, dorsal view; B, habitus, ventral view; C, habitus lateral view; D, carapace, frontal view; E, carapace, dorsal view; F, carapace, ventral view; G, I, left palp, retrolateral view; H, J, left palp, prolateral view. stp, strong, tooth-like projection; e, embolus; l, lobe; vpr, ventral protuberance; elo, ear-like outgrowth. Scale bars A, B, C = 1 mm; D, E, F = 0.5 mm; G, H, I, J = 0.1 mm.

FIGURE 23. Ischnothyreus hooki sp. nov. female. A, habitus, dorsal view; B, habitus, ventral view; C, habitus lateral view; D, abdomen, ventral view; E, G, genital area, ventral view; F, H, genital area, dorsal view. a, apodeme; wt, winding tube. Scale bars A, B, C = 1 mm; D = 0.5 mm; E, F, G, H = 0.1 mm.

FIGURE 24. Ischnothyreus jojo sp. nov. male. A, habitus, dorsal view; B, habitus, ventral view; C, habitus lateral view; D, carapace, frontal view; E, left chelicera, anterior view; F, left palp, retrolateral view; G, left bulb, prolateral view. stp, strong, toothlike projection; pbp, plate-like basal process; sse, saw-shaped extension; vp, ventral projection; vpr, ventral protuberance; l, lobe; spa, small pointed apophysis. Scale bars A, B, C = 1 mm; D = 0.5 mm; E, F, G = 0.1 mm.

FIGURE 25. Ischnothyreus jojo sp. nov. female. A, habitus, dorsal view; B, habitus, ventral view; C, habitus lateral view; D, abdomen, ventral view; E, F, genital area, ventral view; G, genital area, dorsal view. cse, curved, sclerotized extensions; a, apodeme; uss, u-shaped structure; wt, winding tube. Scale bars A, B, C = 1 mm; D = 0.5 mm; E, F, G = 0.1 mm.

FIGURE 26. Ischnothyreus kalimantan sp. nov. male. A, habitus, dorsal view; B, habitus, ventral view; C, habitus lateral view; D, carapace, frontal view; E, left chelicera, posterior view; F, left palp, retrolateral view; G, left bulb, prolateral view. stp, strong, tooth-like projection; ssp, slightly sclerotized process; m, membrane; l, lobe; spa, small pointed apophysis; vp, ventral projection; vpr, ventral protuberance. Scale bars A, B, C = 1 mm; D = 0.5 mm; E, F = 0.1 mm; G = 0.05 mm.

FIGURE 27. Ischnothyreus kalimantan sp. nov. female. A, habitus, dorsal view; B, habitus, ventral view; C, habitus lateral view; D, carapace, frontal view; E, abdomen, ventral view; F, G, genital area, ventral view; H, genital area, dorsal view. a, apodeme; wt, winding tube; ts, translucent sluice. Scale bars A, B, C = 1 mm; D, E = 0.5 mm; F, G, H = 0.1 mm.

FIGURE 28. Ischnothyreus matang sp. nov. male. A, habitus, dorsal view; B, habitus, ventral view; C, carapace, dorsal view; D, carapace, ventral view; E, left palp, retrolateral view; F, left palp, prolateral view. stp, strong, tooth-like projection; m, membrane; vp, ventral projection; vpr, ventral protuberance; l, lobe; sa, spine-like apophysis. Scale bars A, B = 1 mm; C, D = 0.5 mm; E, F = 0.1 mm.

FIGURE 29. Ischnothyreus matang sp. nov. female. A, habitus, dorsal view; B, habitus, ventral view; C, D, genital area, ventral view; E, genital area, dorsal view. wt, winding tube; gls, goblet-like structure. Scale bars A, B = 1 mm; C, D, E = 0.1 mm.

FIGURE 30. Ischnothyreus mulumi sp. nov. male. A, habitus, dorsal view; B, habitus, ventral view; C, habitus lateral view; D, carapace, dorsal view; E, carapace, ventral view; F, carapace, lateral view; G, left chelicera, posterior view; H, left palp, retrolateral view; I, left bulb, prolateral view; J, left bulb, retrolateral view. stp, strong, tooth-like projection; vp, ventral projection; b, brush; bp, basal process; vpr, ventral protuberance; l, lobe; clm, collar-like membrane; bsa, beak-like apophysis; ri, ribbed. Scale bars A, B, C = 1 mm; D, E = 0.5 mm; G = 0.05 mm; F, H = 0.1 mm; I, J = 0.01 mm.

FIGURE 31. Ischnothyreus mulumi sp. nov. female. A, habitus, dorsal view; B, habitus, ventral view; C, habitus lateral view; D, carapace, dorsal view; E, carapace, ventral view; F, abdomen, ventral view; G, H, genital area, ventral view; I, J, genital area, dorsal view. a, apodeme; wt, winding tube; hc, half circle. Scale bars A, B, C = 1 mm; D, E, F = 0.5 mm; G, H, I, J = 0.1 mm.

FIGURE 32. Ischnothyreus rex sp. nov. male. A, habitus, dorsal view; B, habitus, ventral view; C, habitus lateral view; D, carapace, dorsal view; E, carapace, ventral view; F, carapace, frontal view; G, H, left chelicera, anterior view; I, J, left palp, prolateral view. blc, book-lung covers; stp, strong, tooth-like projection; vp, ventral projection; csp, crown-shaped process; vpr, ventral protuberance; l, lobe; mo, membranous outgrowth; e, embolus. Scale bars A, B, C = 1 mm; D, E, F = 0.5 mm; G, H, I, J = 0.1 mm.

FIGURE 33. Ischnothyreus rex sp. nov. female. A, habitus, dorsal view; B, habitus, ventral view; C, habitus lateral view; D, carapace, frontal view; E, G, I, genital area, ventral view; F, left palp, prolateral view; H, genital area, dorsal view. sls, small, lateral sclerite; a, apodeme; yss, y-shaped structure; wt, winding tube. Scale bars A, B, C = 1 mm; D = 0.5 mm; E, F, G, H, I = 0.1 mm.

FIGURE 34. Ischnothyreus serapi sp. nov. male. A, habitus, dorsal view; B, habitus, ventral view; C, carapace, lateral view; D, carapace, frontal view; E, left chelicera, posterior view; F, left palp, ventral view; G, left palp, prolateral view; H, left palp, retrolateral view. stp, strong, tooth-like projection; sbp, small, basal process; b, brush; csb, crown-shaped basis; ri, ribbed; vpr, ventral protuberance; l, lobe; pa, pointed apophysis. Scale bars A, B = 1 mm; C, D = 0.5 mm; E, F, G, H = 0.05 mm.

FIGURE 35. Records of Ischnothyreus species treated in the present study.