Psilogamasus hurlbutti Athias-Henriot, 1969

Both sexes. Dorsal idiosoma with less than 30 pairs of setae; setae z5 of dorsal hexagon similar to j5 and j6 in form (smooth), while different in length (z5 longer); tritosternum biramous; opisthogastric shield bearing five to six pairs of setae; setae ZVI and gland pores gv2 absent (present in P. decemtrichus sp. nov.); seta al of palp femur comblike, all and al2 of palp genu entire and spatulate distally; corniculi small; epistome trispinate.

Female with separated podonotal shield with 16–18 pairs of setae, and opisthonotal shield with five to six pairs of setae (ten pairs in P. decemtrichus sp. nov.); genital shield triangular or subtriangular; peritrematal shield anteriorly fused to podonotal shield and posteriorly free; movable digit of chelicerae with three or four teeth; setae avl and av2 on femur II, avl on genu II and tibia II acicular.

Male with holodorsal shield and transverse suture in central region; movable digit of chelicera with five or six teeth; setae avl and av2 on femur II modified into spurs fused at base; seta avl on genu II and tibia II each modified into spur.

Female. Podonotal and opisthonotal shields with 18 and five pairs of setae, respectively; setae j1 slightly pilose, r3 simple; endogynium comprised of a short semi-circular sac with three to five small teeth on each side of the leading edge; opisthogastric shield bearing six pairs of setae; setae ZV1 and gland pores gv2 absent; Peritrematal groove extending anteriorly to beyond coxa II; movable digit of chelicera with four teeth.

Male. Seta j1 slightly pilose; opisthogastric region with seven pairs of setae; central prong of gnathotectum serrated apically and lateral prongs acuminate distally; movable digit of chelicera with four teeth; dorsal seta on fixed digit of chelicera smooth; femur II with a main spur (proximal) and an axillary process (distal), genu II and tibia II each with a small spur (Fig. 5E). Other characteristics as in female.

Female (N = 4). Idiosoma weakly sclerotized, length 672–710, width 481–498.

Dorsum (Fig. 1A). Podonotal and opisthonotal shields separated and with rough reticulation. Podonotal region with 19 pairs of setae, of which 18 pairs on podonotal shield and a pair (seta r6) off shield. Opisthonotal region bearing seven pairs of setae, of which J1–J3 and Z1, Z2 on opisthonotal shield, J4 and J5 off shield. Seta j1 stout and slightly pilose, other dorsal setae smooth. Seta r3 longer than others, setae j2, j3, z1, z2, s3, s6, r2, r4, r6 and J4 tiny and short. Lengths of dorsal setae: j1 74–78, j2 15–17, j3 32–35, j4 66–70, j5 58–62, j6 58–61, z1 26–28, z2 16–18, z4 47–50, z5 90–95, z6 57–62, s3 31–34, s4 58–61, s5 60–62, s6 15–17, r2 15–17, r3 159–165, r4 15–17, r6 15–17, J1 79–82, J2 78–82, J3 80–84, J4 16–17, J5 92–95, Z1 57–61, Z2 65–69.

Venter (Figs 1B, 2A). Tritosternum with two pilose laciniae (111–120) and a smooth base (42–45). Presternal platelets absent. Sternal shield reticulated, bearing three pairs of setae (st1–st3), st1 (48–52) longer than st2 (38–41) and st3 (42–43). Metasternal shields separated from sternal shield by medially arched groove, bearing setae st4 (39–42). Epigynial shield bearing setae st5 (40–42). Anterior margin of epigynial shield with glassy angulation apex. Endogynium comprised of a short semi-circular sac with three to five small teeth on each side of the leading edge, and anterolaterally with two inner spindle-shaped structures underneath metasternal shields (Fig. 2A). Setae ZV1 and gland pores gv2 absent. Opisthogastric shield reticulate, bearing six pairs of setae (JV1–JV4, ZV2 and ZV3). Setae pa and po equal in length (27–30). Peritrematal groove length 219–238, extending to anterior level of coxa II. Peritrematal shield fused with podonotal shield anteriorly and separated at level of seta j2. Opisthogastric soft cuticle with three pairs of setae. All ventral setae smooth. Lengths of setae on opisthogastric shield: JV1 42–45, JV2 46–49, JV3 47–49, JV4 47–50, ZV2 32–34, ZV3 42–43.

Gnathosoma (Fig. 2B–E). Gnathotectum (Fig. 2B) with three prongs, serrated apically and emerging from base with one to three small teeth on each side. Movable digit of chelicera with four teeth, fixed digit with six teeth (Fig. 2C). Corniculus length 27–34, short and horn-shaped; deutosternal groove with 11 denticulate rows. Setae h1–h3 smooth, h1 46–50, h2 40–43, h3 47–50 in length; pcx pilose, 48–52 in length (Fig. 2D). Palp length 228–239; trochanter with two pilose setae, v1 stouter than v2; femur with five setae, of which al comblike, d3 pilose; genu with six setae, of which al1 and al2 spatulate distally, remaining setae smooth. Trochanter, femur and genu of palp as in Fig. 2E.

Legs (Fig. 3). Lengths of legs I–IV: I 865–910, II 572–634, III 565–642, IV 907–990. Most leg setae smooth and setae on genu IV and tibia IV usually longer than others. Seta al on trochanter I stout and pilose. Most setae on tarsi II and tarsi III slightly pinnate. Setae av1 and pv1 on tarsi II–IV spur-like. Seta pd2 (282–301) on tarsus IV longer than all other leg setae.

Male (N = 3; Figs 4, 5) Idiosoma length 476–495, width 306–317.

Dorsum (Fig. 4A). Reticulate holodorsal shield covering entire dorsum, with a suture closely anterior to setae J1, not reaching lateral margin of idiosoma. Podonotal region with 18 pairs of setae. Opisthonotal region bearing eight pairs of setae. All setae inserted on reticulate holodorsal shield. Seta j1 slightly pilose, other dorsal setae smooth. Setae j2, j3, z1, z2, s3, s6, r2, r4, r6 finer than others. Lengths of dorsal setae: j1 47–50, j2 17–19, j3 27–30, j4 40–44, j5 35–38, j6 35–39, z1 19–21, z2 16–19, z4 29–33, z5 50–55, z6 36–40, s3 24–26, s4 31–33, s5 35–39, s6 21–23, r2 18–20, r3 128–132, r4 14–15, r6 14–15, J1 48–53, J2 55–58, J3 63–67, J4 74–76, Z1 47–48, Z2 51–53, Z3 37–40.

Venter (Fig. 4B). Tritosternum with two pilose laciniae (42–50), and a smooth base (17–20). Presternal shields absent. Genital lamina poorly visible, anteriorly extending to form a hyaline and smooth protrusion. Sternogenital shield bearing five pairs of setae (st1–st5). Anterior margin of sternogenital shield concave, posterior margin fused to opisthogastric region. Opisthogastric region with seven pairs of smooth setae. Setae pa and po equal in length (22–25). Peritrematal groove as in female, length 191–224. Lengths of setae on sternogenital region: st1 35–37, st2 32–34, st3 26–28, st4 26–28, st5 30–32, as well as on opisthogastric one: JV1 30–32, JV2 36–39, JV3 38–40, JV4 47–50, JV5 48–50, ZV2 32–34, ZV3 42–43.

Gnathosoma (Fig. 5). Gnathotectum (Fig. 5A) with three prongs, central one serrated apically and lateral ones acuminate distally, emerging from nude base. Movable and fixed digit of chelicera with four teeth, respectively (Fig. 5B). Palp 189–205 in length, as in female, trochanter, femur and genu as shown in Fig. 5C. Subcapitulum (Fig. 5D) with setae pcx (30–31) pilose, h1 (36–38), h2 (32–35) and h3 (40–43) smooth; deutosternal groove with ten rows, corniculus (23–25) and internal mala acute as in female.

Legs. Lengths of legs I–IV: I 799–812, II 531–544, III 512–539, IV 838–880. Leg II stouter than others. Femur II with a main spur (proximal) and an axillary process (distal), genu II and tibia II each with a small spur (Fig. 5E). Other characteristics as in female.

Unknown.

This species is named after its endogynium, which is composed of a short, semi-circular sac structure.

Holotype. China • 1 ♀ (slide no. XZ2019071901), Xizang Autonomous Region, Linzhi City, Bome County; 29°54'33"N, 95°29'36"E; 2624 m a.s.l.; 19 Jun. 2019; collected from decomposing leaves by Jian-Xin Chen, Paratypes. China • 3 ♀ and 3 ♂ (XZ2019071902–XZ2019071902), the same data as the holotype.

The holotype and paratypes are deposited in the Institute of Entomology, Guizhou University, Guivang, China (GUGC).

The female of the newly described species is morphologically similar to P. bidens Ren & Yi, sp. nov. in the setal numbers on the podonotal, opisthonotal and opisthogastric shields, and the shape of seta j1. However, the female P. brachysaccatus Yao & Jin, sp. nov. is different from P. bidens Ren & Yi, sp. nov. as follows: (1) dorsal seta r3 simple, vs. pilose in the latter; (2) presternal platelets absent, vs. a pair of presternal platelets present in the latter; (3) three prongs of gnathotectum each apically serrated and emerging from base with 1–3 small teeth on each side, vs. bifid and emerging from nude base in the latter; (4) endogynium with a semi-circular sac, vs. tongue-shaped in the latter; and (5) seta v1 on palp trochanter pilose, vs. simple in the latter.

Female. Podonotal and opisthonotal shields with 18 and ten pairs of setae, respectively; setae j1 and r3 simple; endogynium tongue-shaped with some small teeth on each side of the leading edge; setae ZV1 and gland pores gv2 present; opisthogastric shield with six pairs of setae; Peritrematal groove extending anteriorly to beyond coxa II; movable digit of chelicera with three teeth.

Female (N = 5). Idiosoma weakly sclerotized, length 428–468, width 259–278.

Dorsum (Fig. 6A). Podonotal and opisthonotal shields separated and with rough reticulation. Podonotal region with 19 pairs of setae, of which 18 pairs on podonotal shield (seta r5 on podonotal shield) and two pairs (setae r4 and r6) off shield. Opisthonotal shield bearing ten pairs of setae. All dorsal setae smooth, setae z1, s6, r2, r4, r5 and r6 tiny. Lengths of dorsal setae: j1 28–30, j2 35–38, j3 47–49, j4 39–41, j5 47–49, j6 40–42, z1 7–8, z2 27–28, z4 47–50, z5 90–95, z6 57–62, s3 31–34, s4 58–61, s5 60–62, s6 15–17, r2 15–17, r3 159–165, r4 15–17, r5 16–17, r6 17–18, J1 50–54, J2 56–57, J3 63–65, J4 55–59, Z1 50–56, Z2 62–65, Z3 58–59, S1 48–52, S2 48–50, S3 58–60.

Venter (Figs 6B, 7A). Tritosternum with two pilose laciniae (64–73) and a smooth base (24–29). Presternal platelets absent. Sternal shield without reticulation, bearing three pairs of setae (st1–st3), st1 (66–72) longer than st2 (58–64) and st3 (46–50). Metasternal shields separated from sternal shield by medially arched groove, bearing setae st4 (45–52). Epigynial shield bearing setae st5 (35–37). Endogynium tongue-shaped with some small teeth on each side of the leading edge, and anterolaterally with two inner roller-shaped structures underneath metasternal shields, connected by a ribbon structure (Fig. 7A). Setae ZV1 and gland pores gv2 present. Opisthogastric shield reticulate, bearing six pairs of setae (JV1–JV4, ZV1 and ZV2). Setae pa and po equal in length (17–23). Peritrematal groove length 356–379, extending anteriorly to level of coxa II. Opisthogastric soft cuticle with three pairs of setae. All ventral setae smooth. Lengths of setae on opisthogastric shield: JV1 42–45, JV2 46–49, JV3 52–56, JV4 47–48, ZV1 12–15, ZV2 45–48.

Gnathosoma (Fig. 7B–E). Movable digit of chelicera with three teeth, fixed digit with five teeth (Fig. 7B). Corniculus length 23–28, short and horn-shaped; deutosternal groove with ten denticulate rows. Setae h1–h3 smooth, h1 25–5026, h2 21–23, h3 22–25 in length; pcx slightly pilose, 32–36 in length (Fig. 7C). Gnathotectum (Fig. 7D) with three prongs, central one bifid apically and lateral ones acuminate distally, emerging from nude base. Palp length 224–232; trochanter with two setae, v2 slightly pilose; femur with five setae, of which al comblike, d3 pilose; genu with six setae, of which al1 and al2 spatulate distally, remaining setae simple. Trochanter, femur and genu of palp as in Fig. 7E.

Legs (Fig. 8). Lengths of legs I–IV: I 470–481, II 294–326, III 305–320, IV 465–485. Most leg setae smooth. Setae av1 and pv1 on tarsi II–IV spur-like. Setae pd2 on tarsus IV, length 95–107, longer than all other setae.

Unknown.

The name of the species is derived from “ decem-”, meaning “ten”, and–trichus, meaning “setae”. It refers to the opisthonotal shield with ten pairs of setae in females, which is diagnostic for this species.

Holotype. China • 1 ♀ (slide no. YN2022070601), Yunnan Province, Pu’er City, Jingdong Yi Autonomous County, Taizhong Town; 24°32'28"N, 101°1'25"E; 2466 m a.s.l.; 6 Jun. 2022; collected from moss by Ye-Yi Shuai and Gui-Ming Mu. Paratypes. China • 4 ♀ (YN2022070602–YN2022070605), the same data as the holotype.

The holotype and paratypes are deposited in the Institute of Entomology, Guizhou University, Guivang, China (GUGC)

Psilogamasus decemtrichus Ren & Yi, sp. nov. can be easy distinguished from other species of the genus due to the setal number on the opisthonotal shield, which bears ten pairs rather than five or six pairs, and the presence of setae r5, ZV1 and gland pores gv2.

Female. Podonotal and opisthonotal shields with 18 and five pairs of setae, respectively; setae j1 and r3 slightly pilose; endogynium tongue-shaped with some small teeth on each side of the leading edge; opisthogastric shield bearing six pairs of setae; setae ZV1 and gland pores gv2 absent; Peritrematal groove extending anteriorly to beyond coxa II; movable digit of chelicera with four teeth.

Female (N = 4). Idiosoma weakly sclerotized, length 575–668, width 408–425.

Dorsum (Fig. 9A). Podonotal and opisthonotal shields separated and with reticulation. Podonotal region with 19 pairs of setae, of which 18 pairs are on podonotal shield and a pair (seta r6) is off shield. Opisthonotal shield bearing five pairs of setae. Seta J4 off shield. Setae j1 and r3 slightly pilose, j2, z1, z2, r2, r4 and r6 tiny. Lengths of dorsal setae: j1 50–55, j2 8–11, j3 42–46, j4 48–52, j5 53–55, j6 53–58, z1 13–18, z2 9–13, z4 47–50, z5 67–72, z6 63–65, s3 34–38, s4 53–56, s5 56–62, s6 16–20, r2 13–18, r3 113–121, r4 10–13, J1 66–70, J2 75–80, J3 77–82, J4 45–50, Z1 65–70, Z2 61–65.

Venter (Figs 9B, 10A). Tritosternum with two pilose laciniae and a smooth base. Pair of small presternal platelets present. Sternal shield with reticulation, bearing three pairs of setae (st1–st3), st1 (42–46) longer than st2 (34–37) and st3 (33–37). Metasternal shields separated from sternal shield by medially arched groove, bearing setae st4 (30–35). Epigynial shield bearing setae st5 (37–43). Endogynium saccular, tongue-shaped in ventral view, with some small teeth on each side, and anterolaterally with two inner reniform structures (Fig. 10A). Setae ZV1 and gland pores gv2 absent. Opisthogastric shield reticulate, bearing six pairs of setae (JV1–JV4, ZV2 and ZV3). Setae pa (22–25) and longer than po (15–17). Peritrematal groove length 178–188, extending to anterior level of coxa II. Peritrematal shield fused with podonotal shield anteriorly and separated at level of seta j2. Opisthogastric soft cuticle with two pairs of setae. All ventral setae smooth. Lengths of setae on opisthogastric shield: JV1 37–42, JV2 40–44, JV3 44–47, JV4 47–50, ZV2 47–51, ZV3 49–53.

Gnathosoma (Fig. 10B–E). Gnathotectum (Fig. 2B) with three prongs, each apically bifid and emerging from nude base. Corniculus length 32–38, short and horn-shaped; deutosternal groove with ten denticulate rows. Setae h1–h3 smooth, h1 52–58, h2 40–43, h3 57–63 in length; pcx pilose, 70–75 in length (Fig. 10C). Movable digit of chelicera with four teeth, fixed digit with five teeth (Fig. 10D). Palp trochanter bearing two setae, v2 pilose; femur with five setae, of which al comblike; genu with six setae, of which al1 and al2 spatulate distally, remaining setae smooth. Trochanter, femur and genu of palp as in Fig. 10E.

Legs (Fig. 11). Lengths of legs I–IV: I 783–850, II 518–576, III 508–580, IV 937–970. Most leg setae smooth and setae on femur IV, genu IV, tibia IV and tarsi IV usually longer than setae on other legs. Most setae on tarsi II and tarsi III slightly pinnate. Setae av1 and pv1 on tarsi II–IV spur-like.

Unknown.

This new species is named based on the three prongs of the gnathotectum, where each prong exhibits an apical bifurcation (bidens).

Holotype. China • 1 ♀ (slide no. YN2024051601), Yunnan Province, Honghe Hani and Yi Autonomous Prefecture, Pingbian County, Daweishan National Nature Reserve; 22°54'48"N, 103°41'47"E; 2038 m a.s.l.; 16 May, 2024; collected from decomposing leaves by Hu-Die He and Rong Ren. Paratypes. China • 1 ♀ (YN2024051602), the same data as the holotype. China • 1 ♀ (YN2024052901), Yunnan Province, Baoshan City, Longyang District, Mangkuan Yi and Dai Ethnic Township, Gaoligong Mountain National Nature Reserve; 25°17'28"N, 98°46'17"E; 2392 m a.s.l.; 29 May, 2024; collected from decomposing leaves by Hu-Die He and Rong Ren. China • 1 ♀ (YN2024051701), Yunnan Province, Honghe Hani and Yi Autonomous Prefecture, Mengzi City; 23°11'25"N, 103°22'54"E; 1649 m a.s.l.; 17 May, 2024; collected from moss by Hu-Die He and Rong Ren.

The holotype and paratypes are deposited in the Institute of Entomology, Guizhou University, Guivang, China (GUGC)

The female of the newly described species is morphologically similar to P. longascidiformis in the setal number on the opisthonotal shield, dental number of the fixed digit on chelicera, and the endogynium with a tongue-shaped suck. However, the female P. bidens Ren & Yi, sp. nov. is different from P. longascidiformis as follows: (1) opisthogastric shield bearing six pairs of setae, vs. five pairs in the latter; (2) dorsal setae j1 and r3 pilose, vs. simple in the latter; (3) fixed digit of chelicera with four teeth, vs. three in the latter; and (4) setae j3 about four times longer than j2 in length, vs. equal in the latter.