Middle-sized callipodidans with well-developed pleurotergal crests, poriferous ones prominent; male head either unmodified or with a prominent bulge. Pleurotergal setae apically pointed, usually in anterior position until PT4, on PT 5 some setae migrate posteriorly, and from PT6 all are in posterior position. Gonopods: parallel, diverging or converging. Sternum reduced or fused with coxae; coxae freely connected through a medial membranous lamina. Each gonopod with one or two prefemoroidal processes clavate and setose (pf1, pf2); one or two coxal lobes and a mesal coxal process varying in size; telopodite (T) long, unbranched in proximal parts, sometimes curved, twisted or forming a sharp angle at mid-length, distally complex with apical folds and lamellae and smaller projections, ending with solenomere (s) and parasolenomere (ps). Leg 2 in adult females reduced to two simple sclerites.

In most representatives of the family we examined, the chaetotaxy in the anterior pleurotergites is the same and follows this distribution (Table 1), except in the Vietnamese species Paracortina multisegmentata and P. kyrang. As already established by Wang and Zhang (1993), some paracortinids have a greater number of setae on each hemipleurite (6 or 7) from PT 6 onwards. However, the majority of the species show a 5+5 pattern.

AngulifemurZhang 1997 – two species.

Crassipetalum Akkari & Stoev, gen. nov. – two species.

Paracortina Wang & Zhang, 1993 – 13 species.

ScotopetalumShear 2000, stat. rev. – two species.

Angulifemur tridigitis Zhang, 1997.

Angulifemur tridigitis Zhang, 1997; Angulifemur unidigitis Zhang, 1997.

Head with no projection on vertex, leg-pair 7 with a long subfalcate mesal process and a broader triangular one on coxa. Gonopods diverging from the base. Each gonopod with two short, clavate, uniformly setose prefemoroidal processes (pf1 and pf2); reduced coxal processes: (a) an anterior lobe-like projection and (b) a generally reduced thin, hyaline subfalcate or cone-shaped process not reaching telopodite’s mid-length. Telopodite (T) with a stout stem forming an angular projection at ~ 1/3 to mid-length, distal part twisting and sharply narrowing, tapering towards its apex. Telopodite distally twisted, with one (A. unidigitis) or more (A. tridigitis) spine-like or tooth-like processes. Differs from Paracortina and Scotopetalum by the diverging stems of telopodite and from the genus Crassipetalum gen. nov. by the much smaller prefemoroidal process/es and a subfalcate coxal process (b) never surpassing the telopodite.

It can easily be distinguished from A. unidigitis by having larger falcate coxal process (b) nearly reaching mid-length of the telopodite, much less sinuous distal part of telopodite (T) and more angular projection (Tp). Distal part of the telopodite differing in the presence of two downturned spine-like processes (vs one in A. unidigitis).

Known only from the original description (Zhang 1997).

Known only from Yang-fen and Niupeng-yanzi caves in Mengzi County, Yunnan, China (Fig. 28)

1 female, China, Yunnan, Menzi County, Wulichong Sinkhole Cave (No 3), 04.01.1989, P. Beron leg. (BG-NMNHS-INV-000000006259 NMNHS), Stoev det. 25.07.2003, 1 male, China, Yunnan, Menzi County, Long Bao Pao Dong (cave), 07.01.1989, P. Beron leg. (BG-NMNHS-INV-000000006260 NMNHS).

It can easily be distinguished from A. tridigitis by the much shorter and upright coxal process, a distally more sinuous telopodite, bearing a pointed process at its mid length (Tp); distal part of telopodite with one tooth-shaped process (k).

Habitus matching the description of Paracortina wangi (Stoev 2004). The species is characterised by long walking legs and antennae, absence of projection on head vertex in adult males, reduced number of ommatidia and a strongly enlarged organ of Tömösváry (Fig. 1).

Leg-pairs 1 and 2 reduced and more setose than the rest, showing prefemoral and tarsal brushes (Fig. 1E), leg-pair 2 with a small anterior process and posterior gonopore, leg-pair 3 with a smaller triangular process on coxa (Fig. 1E), leg-pair 6 with one small hyaline triangular mesal process on coxa, prefemur showing proximally a constriction on the posterior margin (Fig. 26A), leg-pair 7 with two coxal processes (Fig. 26B), a long subfalcate mesal process and a shorter, larger, subtriangular one (corresponding to f and t, respectively in Stoev 2004: fig. 6), coxal sacs (Fig. 1E) present on leg-pair 3–23.

Gonopods (Fig. 2). Each gonopod with two short, clavate, setose prefemoroidal processes (pf1 and pf2), with pf1 slightly larger and more setose than pf2 (Fig. 2A, C). Coxa with two reduced processes on the median margin: (a) a rounded lobe directed mesad (Fig. 2A, C, D), and (b) a reduced, cone-shaped one, pointing distad (Fig. 2 A, B, D). Telopodital (T) stem proximally broad, with a pointed triangular projection (Tp) at the third to mid-length of its posterior margin, marking an abrupt twist and narrowing of the process (Fig. 2A–D). Distal half of T sinusoidal, gently narrowing distad, and bent laterad. Distal part of T darkly pigmented, with a sharp triangular tooth (k) and a much smaller blunt one (tb) on the lateral margin (Fig. 2B–D). T further narrowing distad, marking a complete loop, its apex projecting in a short curved downturned process, bifurcated into solenomere (s) and parasolenomere (ps).

The specimens studied here are part of the type series of the species Paracortina (Altum) wangi Stoev, 2004. Stoev (2004) described this millipede as a new species of the genus Paracortina and subgenus Altum based on the presence of five posterior setae on the sixth hemipleurite. While describing P. wangiStoev (2004) was unaware of the publication of Zhang (1997). Being also described from the same type locality (Longbaopo-Wulichong cave system) in Mengzi County, Stoev et al. (2008) subsequently synonymised P. wangi with Angulifemur unidigitis.

Until now, the species is known only from Long Bao Pao - Wulichong cave system and Laoxiao Cave, Mengzi County, China (Fig. 28).

Crassipetalum magnum Akkari & Stoev, sp. nov.

Crassipetalum magnum Akkari & Stoev, sp. nov.; Crassipetalum inflatum (Chen, Zheng & Jian, 2023), comb. nov.

Head with no projection on vertex, leg-pairs 6 and 7 without noticeable modifications. Gonopods parallel, distal part of the telopodites crossing. Each gonopod with a large clavate prefemoroidal process (pf1) reaching the distal part of telopodite (and sometimes accompanied by a smaller one); coxa with a protruding rounded anterior projection and a large coxal process, latter almost of the same size as the telopodite. Telopodite (T) with a stout stem, distally expanding in three main folds including a horizontal mesal projection accommodating the solenomere (s) and parasolenomere (ps). Different from all the other genera of Paracortinidae by the enlarged mesal falcate coxal process and prefemoroidal process, and by the shape of the distal part of the telopodites.

A combination of crassus, meaning fat/stout, referring to the large mesal coxal process and petalum a suffix used in many genera in the order Callipodida.

Holotype: adult male, China, Gansu Province, Cha-gang Village, Zhou-qu County, alt. 1650 m., on 12.05.1998, leg. Chen De-niu, Zhang Guo-qia (TM_206979 IZCAS).

Species epithet refers to the unusually large mesal coxal and prefemoroidal processes.

Different from Crassipetalum inflatum by the larger and elongated shape of the prefemoroidal process, the absence of a second prefemoroidal process, and the different distal part of telopodite.

Body cylindrical, length 37–38 mm, maximal width ca 2.2 mm at PT6; body narrowing anteriad and posteriad from PT6; 54 (52 + 2 apodous) pleurotergites (PTs) + telson. Live colour unknown. Preserved specimen with yellow to pale brownish metazona (Fig. 3A, B); prozona greyish white (Fig. 3B); no stripes or other particular colour patterns; legs yellowish (Fig. 3C). Head: same colour as the body, vertex slightly darker, antennae whitish yellow (Fig. 3A). Fields of ommatidia subtriangular, blackish, composed of ~ 65 transparent ommatidia in eight rows from dorsal to ventral. Organ of Tömösváry ~ 2–3 × larger than ommatidium, situated close to and touching anterior side of eye. Head convex, with no particular modifications (Fig. 3C), covered with minute setae. Antennae short, extending backwards to around mid-length of PT5 (Fig. 3A, C); length of antennomeres (mm): 1 = 0.2; 2 = 0.87; 3 = 0.7; 4 = 0.76; 5 = 0.32; 6 = 0.45; 7 = 0.19. PTs composed of smooth prozona and carinate metazona, latter being greater in diameter than prozona. Prozona without crests, anterior part of metazona with scale-like ornamentation followed by a sharply raising posterior part forming well-developed longitudinal narrow and subparallel crests (Fig. 3B), well-separated from one another and extending over whole-body ring; crests gradually reduced in size laterally and ventrally. Chaetotaxy: all setae in anterior position on PTs 1–4, setae b, c, e migrated posteriorly on PT5; all setae on posterior position from PT6 onwards. Crests well developed, also on collum, comprising primary and secondary series; collum with seven or eight crests on each hemipleurite. Ozopores visible from sixth to the 49^thPT, located on fourth (largest) crest. Hypoproct tripartite, median sclerite largest, subrectangular, bearing a pair of basal macrosetae; lateral sclerites smaller, triangular, with one seta each. Paraprocts divided into large ventral and smaller dorsal sclerites, each paraproct with a pair of long macrosetae. Spinnerets long and slender, arising from the caudal edge of epiproct and extending well beyond the margins of paraprocts.

PTs 6 and 7 enlarged, leg-pairs 1 and 2 reduced and more setose than the rest, showing femoral and tarsal “brushes”, leg-pair 2 with posterior gonopore, legs 1–7 without noticeable modifications (Fig. 3C), coxal sacs present (visible) on leg-pairs 3–16.

Gonopods (Figs 3C, D, 4). Parallel, distally crossing. Each gonopod with one elongated, setose, clavate prefemoroidal process (pf1), reaching the distal part of telopodite (Fig. 4A, C, D). Setae of prefemoroidal process large and dense. Coxa with a protruding rounded anterior lobe (Ca) (Fig. 4D) and a large coxal process (b), almost of the same size as telopodite (Fig. 4), narrowing at mid-length and apically projecting in a pointed tip lodged in small lateral notch of the distal part of the telopodite (Fig. 3D). Telopodite (T) with a stout stem, distally with a large lateral triangular downturned projection (k), a large mesal notch (n) separating a mesal spur-like process (p) and a posterior plateau-like horizontal process with a bifurcated mesal projection accommodating the solenomere (s) and parasolenomere (ps).

Female unknown.

Zhou-qu County, Cha-gang Village, China (Fig. 28).

Different from Crassipetalum magnum Akkari & Stoev, sp. nov. by the ovoid shape of the prefemoroidal process, the presence of a second, smaller prefemoroidal process, and by the differently shaped and more complex distal part of the telopodite (Chen et al. 2023).

Hongqi Longtan Cave, Yintiaoling National Nature Reserve, Wuxi County, Chongqing, China (Fig. 28).

Paracortina leptoclada Wang & Zhang, 1993.

P. asciformis Akkari & Stoev, sp. nov. – Lixian County, Sichuan, China.

P. carinata (Wang & Zhang, 1993) – Shangrila County (=Zhong Dian/ Zhongdian County), Yunnan, China.

P. kabaki Akkari & Stoev, sp. nov. – Shangrila County, Yunnan, China.

P. kyrang Nguyen, Stoev, Nguyen & Vu, 2023 – Ky Rang Cave, Quoc Toan Commune, Quang Hoa District, Cao Bang, Vietnam.

P. leptoclada Wang & Zhang, 1993 – Shangrila County, Yunnan, China.

P. multisegmentata Stoev & Geoffroy, 2004 – Ngọc Lặc County, Thanh Hoa District, Vietnam.

P. serrata (Wang & Zhang, 1993) – Deqin County, Yunnan, China.

P. stimula (Wang & Zhang, 1993) – Shangrila County, Yunnan, China.

P. thallina (Wang & Zhang, 1993) – Batang County, Sichuan, and Shangrila County, Yunnan, China.

P. viriosa (Wang & Zhang, 1993) – Shangrila County, Yunnan, and Mang kang County/Markam? County, Tibet Autonomous Region, China.

P. voluta Wang & Zhang, 1993 – Yajiang County and Yanyuan County (new record), Sichuan, China.

P. yinae Liu & Tian, 2015 – Cave in Yanchang Village, Guangxi, China.

P. zhangi Liu & Tian, 2015 – Cave Qiaoxia Dong, Guizhou, China.

The type genus of the family Paracortinidae, which differs from Angulifemur by having parallel stems of telopodites; from Scotopetalum by the presence of large anteromedian subfalcate coxal process, and from the genus Crassipetalum gen. nov. by the much smaller prefemoroidal process/es and a subfalcate coxal process b (never surpassing the telopodite).

Holotype: 1 adult male China, Sichuan Prov., Lixian County, SW of Tonghua Village, 31°33'29"N, 103°19'36"E, 08.07.2012, alt. 1905 m, I. Belousov & G. Davidian leg. (Rd 5347 ZMUM); paratype: 1 adult female, 60 PTs + telson, same data as holotype (Rd 5348 ZMUM).

The species epithet ascia + formis, referring to the distal shape of the telopodite having a shape of an axe in lateral view. Adjective.

Different from all other species of the genus Paracortina by the distinctive shape of the distal part of telopodite resembling an axe.

Length 39 mm, maximal width ca 2.3 mm at PT6; body narrowing anteriorly and posteriorly from PT6; 60 (59 + 1 apodous) pleurotergites + telson. Live colour unknown. Preserved specimen dark brown, metazona dorsally dark brown, especially on crests, laterally and ventrally paler; prozona greyish; legs yellowish (Figs 5A, 6A). Head: frontal part yellowish, vertex slightly dark brown, antennae yellow (Figs 5C, 6A).

Fields of ommatidia subtriangular, blackish, composed of ~ 56 transparent ommatidia in eight or nine rows (Fig. 5B). Organ of Tömösváry ~ 2 × an ommatidium situated close to and touching anterior side of eye. Antennae moderately long (Figs 5C, 6A). Length of antennomeres (mm): 1 = 0.12; 2 = 0.93; 3 = 0.86; 4 = 0.58; 5 = 0.65; 6 = 0.33; 7 = 0.11. PTs composed of smooth prozona and carinate metazona (Fig. 5D, E), latter being more pronounced and greater in diameter in the posterior part. Prozona void of crests, anterior part of metazona with low carinae followed by a sharply raising posterior part forming well-developed longitudinal narrow and subparallel crests, well-separated from one another; crests gradually reduce in size laterally and ventrally (Fig. 5C–E). Chaetotaxy follows the pattern of all setae being in anterior position on PTs 1–4, setae b, c, e migrating posteriorly on PT5 and all setae posteriorly on PT6 onwards. Crests moderately developed, also on collum, comprising alternating primary and secondary series, primary slightly higher than secondary; collum with ca nine crests on each hemipleurite. Ozopores visible from 6^th to 59^thPT, located on 6^th (largest) PT. Hypoproct tripartite, median sclerite largest, subrectangular, bearing a pair of basal macrosetae; lateral sclerites smaller, triangular, with one seta each. Paraprocts divided into large ventral and smaller dorsal sclerites, each pair with a pair of long macrosetae. Spinnerets long and slender, arising from the caudal edge of epiproct and extending well beyond the margins of paraprocts (Fig. 6B).

Head with a pronounced beak-shaped projection (Figs 6C, 7A), covered with minute setae. Leg-pairs 1 and 2 reduced and more setose than the rest, leg-pair 2 with a small anterior process and posterior opening of the gonopores, leg-pair 7 with a protruding curved mesal process pointing laterad and a shorter subtriangular one on coxa, trochanter with an anterior triangular projection covered with setae (Fig. 27E) Coxal sacs present (noticeable) on leg-pairs 3–13/16.

Gonopods. Parallel, each gonopod with two short, slender, clavate, asymmetrical, and apically setose prefemoroidal processes pf1 and pf2 (Fig. 7B–D); coxa with a low rounded lobe on the anterior margin (Ca), one long falcate mesal coxal process (b), reaching the distal part of the telopodite, its distal part showing ca four beaded structures (Fig. 6C). Telopodite (T) stout, with a broad stem proximally, gradually narrowing until its distal third before expanding in two main darkly pigmented parts separated by a rounded notch (n), the larger part axe-shaped (Fig. 7C, D), showing a round apical margin and a sharp triangular opposite end (k), second part as a slender curved stem, apically bifurcated in solenomere (s) and parasolenomere (ps) and bearing a smaller subapical triangular tooth (M) (Fig. 7).

Known only from its type locality (Fig. 28).

P. carinata appears most similar to P. stimula especially in the expanded distal part of the telopodite, of which the distal part is downturned and crossing with the curved process of the solenomere, differing in the shape of the distal process, showing as a subrectangular plate in carinata vs dome-shaped in P. stimula. Both species could be recognised also by the body colouration which is dark brown in P. carinata and yellow in P. stimula.

(based on Wang and Zhang 1993) Holotype 42 mm long, 2.5 mm wide, 60 podous + 2 apodous PTs, with a dark brown colour.

Gonopods. Each gonopod with two asymmetrical prefemoroidal processes (pf1, pf2), with pf1 larger and more setose than pf2, a stout and falcate coxal process, reaching 2/3^rd of the telopodite; telopodite (T) with a uniformly broad stem, distal part abruptly expanding antero-posteriad and showing in a lateral view (Wang and Zhang 1993, fig. 29) a subrectangular plate with an irregular apical margin, and a notch on the anteromesal side separating the main branch from a curved narrow process pointing distad, terminating in a slender branch bifurcated in solenomere (s) and parasolenomere (ps).

Shangrila (= Zhong Dian) County, Yunnan, China (Fig. 28).

Known only from its original description (Wang and Zhang 1993).

Holotype: China, Yunnan, Shangrila County, Degen, 214 Ntn Road, NE slope of SE Baima Mt. Range, between Cukatongcun & Nali, alt. 2465 m, 28°2'23"N, 99°12'16"E, 8.06.2013, I. Belousov, I. Kabak & G. Davidian leg. (Rd 5349 ZMUM); Paratype: 1 male 54PTs, same data as holotype (Rd 5350 ZMUM).

The species epithet is a patronym to honours of one of the collectors, Ilya Kabak from the Zoological Institute of the Russian Academy of Sciences St Petersburg. Noun in the genitive case.

Different from all species of the genus Paracortina by the distinctive shape of the distal part of telopodite with the ruffle of distolateral lamella.

Body cylindrical, length 77.4 mm, maximal width ca 3.2 mm at PT5; body narrowing anteriorly and posteriorly from PT6; 60 (59 + 1 apodous) pleurotergites (PTs) + telson. Live colour unknown. Preserved specimen with a general dark brown to greyish aspect contrasted with pale legs and antennae (Fig. 8A, B), prozona greyish, sputtered with fine brown dots (Fig. 8A, D); metazona dorsally dark greyish brown especially on crests, anterior part greyish, finely sputtered with pale brown interrupted by larger irregular yellow alveolate spots, colour paler laterally below the ozopores and ventrally; legs yellowish (Fig. 8C, D). Head: frontal part pale brown to yellowish, vertex dark grey-brown, antennae yellow (Fig. 8A, B).

Fields of ommatidia subtriangular, black, composed of ~ 75 transparent ommatidia in nine or ten rows. Organ of Tömösváry large, ~ 1.2 mm, 3 × as large as an ommatidium, situated close to and touching anterior side of eye (Fig. 8A). Antennae long; length of antennomeres (mm): 1 = 0.18; 2 = 1.29; 3 = 1.27; 4 = 1.01; 5 = 1.08; 6 = 0.69; 7 = 0.23.

PTs composed of smooth prozona and carinate metazona, latter being more pronounced in the posterior part. Prozona with no crests, anterior part of metazona with low, fine carinae, posterior part sharply raising forming well-developed longitudinal narrow and subparallel crests, well-separated from one another; crests gradually reduce in size laterally and ventrally (Fig. 8C). Chaetotaxy follows the pattern of all setae being in anterior position on PTs 1–4, setae b, c, e migrating posteriorly on PT5 and all setae posteriorly on PT6 onwards. Crests moderately developed, also on collum, comprising alternating primary and secondary series, primary slightly higher than secondary; collum with ca nine crests on each hemipleurite. Ozopores visible from 6^th to 59^thPT, located on 6^th (largest) PT. Hypoproct tripartite, median sclerite largest, subrectangular, bearing a pair of basal macrosetae; lateral sclerites smaller, triangular, with one seta each. Paraprocts divided into large ventral and smaller dorsal sclerites, each pair with a pair of long macrosetae. Spinnerets long and slender, arising from the caudal edge of epiproct and extending well beyond the margins of paraprocts.

Head with a pronounced beak-shaped projection covered with minute setae (Fig. 8A, B). Leg-pairs 1 and 2 reduced and more setose than the rest, leg-pair 2 with a small anterior process and posterior opening of the gonopores. Leg-pair 7 with a large cone-shaped and apically rounded mesal process on coxa, a lateral angular margin separated by a notch, an apical tuft of setae on trochanter, prefemur with a strong constriction proximally on the anterior margin, then strongly swollen distally (Fig. 27F). Coxal sacs present (noticeable) on leg-pairs 3–13/16.

Gonopods (Figs 9, 10). Parallel, each gonopod with asymmetrical, clavate prefemoroidal processes: a thin, short (pf1) process bearing a few apical setae, and a much larger densely setose (pf2) one (Fig. 9A, B); coxa with rounded lobes on the anterior side (Ca) and the lateral side (Cl) respectively, engulfing the prefemoroidal processes (Fig. 9 A), and a long falcate mesal coxal process (b), reaching the distal part of the telopodite (Fig. 9A, B, D). Telopodite (T) stout and straight, with a uniformly broad stem expanding distally in a complex apex comprising a large hyaline lamella (dl) with a serrated margin extending anterolaterally in a double horizontal ruffle (Fig. 9B), and a darkly pigmented median projection (dp) apically folded and pointing distolaterad (Figs 9, 10); a slender mesal process, curved 180 degrees and pointing anteriad, slightly swollen apically (Figs 9C, D, 10A) before further narrowing and bifurcating in solenomere (s) and parasolenomere (ps).

The gonopods of this species differ from those of the other congeners in the sinuous aspect of the telopodite, distally narrowing, reminding more of the genus Angulifemur, from which this species differs by the absence of (Tp) process and the presence of a long coxal process (b) reaching the distal part of telopodite.

(based on Nguyen et al. 2023) Species with 68–74 PTs + telson, general colour pale, living specimens greenish-white, head strongly modified in males with a well-protruding projection, 19–20 ommatidia in two or three rows.

PTs 6 and 7 strongly enlarged, leg-pairs 1 and 2 smaller and more setose than the rest, showing femoral and tarsal “brushes”, leg-pair 2 with a small anterior process and posterior gonopore, leg-pair 7 with a round mesal projection and a small spine (Nguyen et al. 2023: fig. 6a, b), coxal sacs present on leg-pairs 3–26.

Gonopods. Each gonopod with two clavate, slender, and setose prefemoroidal processes (pf1, pf2), coxa low with anterior and lateral rounded lobes and a long falcate mesal process, reaching the distal part of the telopodital stem. Telopodite (T) sinuous bearing a distomesal triangular tooth, further twisted and expanding mesolaterad, then strongly constricted and apically narrowed, terminating in a slender branch bifurcated into solenomere (s) and parasolenomere (ps).

Ky Rang Cave, Quoc Toan commune, Quang Hoa District, Cao Bang Province, Vietnam (Fig. 28).

Nguyen et al. (2023) described a slightly different chaetotaxy for Paracortina kyrang with two pairs of setae distributed posteriorly on the collum (usually all setae are positioned anteriorly) and five pairs of posterior setae on PT5 (instead of three pairs).

Most similar to P. thallina, with an expanded distal part of the telopodite bearing a large rounded lateral lamella and a hook-shaped process pointing anterodistad. Different in the shape and orientation of the distal lamella, laterally positioned and folded 180 degrees and a shorter mesal coxal process.

Male holotype 55 mm long, 2.3 mm wide, general colour brown, 55 podous +2 apodous PTs, coxa of leg pairs 1 and 7 with two processes (Wang and Zhang 1993; Wang 1996), head with a large projection on the vertex (Wang 1996).

(based on Wang and Zhang 1993: fig. 19) Leg-pair 7 with two processes on coxa.

Gonopods. Parallel and slightly diverging. Each gonopod with two uniformly setose, clavate prefemoroidal processes (pf1 and pf2), one large falcate coxal process narrowing at mid-length and apically projecting in a pointed tip, reaching the distal part of the telopodite. Telopodite (T) with a stout stem, distally expanding in a larger process projecting in a broad lateral folded lamella and a thin curved mesal process pointing anterodistad, apically bifurcated to accommodate the solenomere (s) and parasolenomere (ps).

Shangrila County, Yunnan, China (Fig. 28).

Species known only from its original description.

1 male paratype, Vietnam, Thanh Hoa Province, Ngọc Lặc, Moc–Trach Cave, alt. 15 m, 8–10.12.1929, Colani leg. (BG-NMNHS-INV-000000006261 NMNHS). Stoev det. April 2004.

Unique in having the highest number (81–85) of pleurotergites and gonopods with proximally crossing telopodites, distally bent at 90 degrees.

Species with 81–85 PTs + telson, general colour of conserved specimens pale brownish (Fig. 11A, B), head convex, unmodified (Figs 11A, 12A), ~ 40 ommatidia in five or six rows (Fig. 11A).

PTs 6 and 7 strongly enlarged, leg-pairs 1 and 2 reduced and more setose than the rest, showing prefemoral and tarsal brushes, leg-pair 2 with the posterior gonopore (Fig. 12A, B), leg-pair 7 with a small mesal spine on coxa and a tuft of setae on trochanter (Fig. 26C), coxal sacs present on leg-pairs 3–23.

Gonopods (Figs 12B, 13). Converging, proximally crossing (Fig. 12B). Each gonopod with one slender and distally uniformly setose prefemoroidal process (pf1), reaching to overpassing the mid-length of telopodite (Fig. 13); coxa with a mesal rounded lobe (a) connected to a slender falcate mesal process (b), latter reaching mid-length of the telopodite. Telopodite (T) with uniformly slender stem, distally 90 degrees bent laterad (Fig. 12A, B), distal part expanding and terminating in two asymmetrical branches (Fig. 13): a shorter horizontally leaf-like subapical process, surmounted by a triangular tooth (k) pointing distolaterad, second branch longer, extending laterad before curving distad, with the apical part terminating in two asymmetrical bulges, the largest accommodating the bifurcated branch with the opening of the solenomere (s) and parasolenomere (ps).

Ngoc-Lac and Loc Thinh, Thanh Hoa, Vietnam (Fig. 28).

This species possesses unique characters within the family, not only by having the highest number of pleurotergites but also in being the only species of Paracortinidae with telopodites proximally crossing and their distal part being bent to 90 degrees. This combination of characters could justify the description of a new genus to accommodate the species. However, similar to P. kyrang, until more material becomes available, we refrain from erecting new genera for these two species and leave them in the genus Paracortina until further analyses are available.

Most similar to the new species P. kabaki sp. nov., especially in the distal part of the telopodite with a large, serrated lamella, differing by the short trapezoid lamella (vs larger rectangular one).

Holotype 45 mm long, 2.9 mm wide, 52 podous + apodous PTs, general colour brown.

Leg-pair 7 with two coxal processes (Wang and Zhang 1993; Wang 1996). Gonopods (based on Wang and Zhang 1993: figs 24–26). Parallel, each gonopod with two asymmetrical, clavate prefemoroidal processes, with (pf1) larger and more setose than (pf2), the latter distally folded; one large broad and long coxal process (b), reaching the distal part of the telopodite and apically projecting in a pointed tip. Telopodite (T) with a stout stem, distally expanding into a lateral lamella with a serrated margin, separated by a deep notch from a median branch. Latter presenting a blunt subapical projection, and a longer twisted process, curved and bifurcating at the tip, with the opening of the solenomere (s) and parasolenomere (ps).

Deqin County, Yunnan, China (Fig. 28).

Species known only from its original description.

Most similar to P. carinata, differing in the distal process, being dome-shaped (vs sub rectangular in P. carinata). Both species could be recognised also by the body colouration which is dark brown in P. carinata and yellow in P. stimula.

Holotype 35.5 mm long, 1.9 mm wide, number of PTs in holotype not specified, in female allotype 53 podous + 3 apodous; general colour light yellow (Wang and Zhang 1993).

Gonopods (based on Wang and Zhang 1993: figs 10, 11). Each gonopod with two asymmetrical clavate prefemoroidal processes with (pf1) large and setose, (pf2) small with only a pair of large setae; one large falcate coxal processes (b) reaching the distal part of the telopodite, apically projecting in a pointed tip. Telopodite (T) with a stout stem, distally expanding into dome-like plate, with a notch on the mesal margin separating two oppositely directed crossing projections of more or less similar length: a downturned projection and upturned process pointing distomesad, bifurcated at tip with the opening of the solenomere (s) and parasolenomere (ps).

Shangrila (= Zhong Dian) County, Yunnan, China (Fig. 28).

Species known only from its original description.

1 male, China, Yunnan, Shangrila, Degen, SW of Benzibanzhen, 214 Nm Road, NE slope of SE Baima Mt. Range, 28°6'50"N, 99°12'24"E, alt. 3260, 07.06.2013, I. Belousov, I. Kabak & G. Davidian leg. (Rd 5344 ZMUM), Stoev & Akkari det. 2023.

Most similar to P. leptoclada in the expanded distal part of the telopodite bearing a large rounded lateral lamella and a hook-shaped process pointing anterodistad. Different in the shape and orientation of the distal lamella, (vs laterally expanded and folded lamella and a shorter mesal coxal process in P. leptoclada).

Male with 55 PTs + Telson. Length ca 39.7 mm. Live colour unknown. Preserved specimen with a general dark brown to greyish colour, legs and antennae yellowish with a dark sputter (Figs 14, 15A), prozona greyish with fine brown sputter (Figs 14A, 15B); metazona dark greyish brown dorsally especially on crests, anterior part greyish with a fine pale brown sputter interrupted by larger irregular yellow alveolate spots, colour gradually fading below the ozopores and ventrally. Head with dark pigmentation on the vertex and frons, mandibular stipes and gnathochilarium yellowish (Fig. 14B, C). Fields of ommatidia subtriangular, composed of ~ 62 ommatidia in ten rows. Organ of Tömösváry very large, ~ 0.8 mm, situated close to and touching the anterior side of eye (Fig. 14B).

Head with a triangular protruding projection on vertex (Figs 14B, C, 15A). Leg-pairs 1 and 2 reduced and setose (Fig. 14C), showing prefemoral and tarsal brushes, leg-pair 2 with a dome-shaped anterior process on coxa and posterior gonopore, leg-pair 4 with an anterior triangular process on coxa (Fig. 15A), leg-pair 6 with a small mesal tooth on coxa (Fig. 26D), leg-pair 7 with one mesal and one lateral slender hyaline pointed processes on coxa (Fig. 26E), coxal sacs (Fig. 15C) noticeable from leg-pair 3–23.

Gonopods (Figs 15D, E, 16). Diverging. Each gonopod with two large, setose, clavate prefemoroidal processes (pf1, pf2) with pf1 slightly larger than pf2 (Fig. 15D); coxa with a large lobe laterally (Cl) and a low projection (Ca) anteriorly (Figs 15D, 16), a mesal anterior triangular process (a) and a long falcate coxal processes (b) reaching the distal part of the telopodite (both broken in the studied specimen). Telopodite (T) with a long slightly curved stem, distally abruptly expanding in a sub-rectangular posterior process with rounded margins (Fig. 16C, D) connected to a transparent jagged lamella (dl) projecting anteriad (Fig. 15D), apically folded (Fig. 16C, D), and a curved hook-shaped process pointing meso-anteriad (Fig. 16), narrowing towards its apex and bifurcating into the opening of the solenomere (s) and parasolenomere (ps).

Batang County, Sichuan, and Shangrila County, Yunnan, China (Fig. 28).

This is the second record of the species since its original description. Here we provide the first micrographs illustrating the habitus of the species (Figs 14, 15).

1 male, China, W Lijiang, W Yangtze, W Xinhuacun, 0.7 km NW Daqingtou, 26°56'23"N, 99°52'16"E, 2720m, 01.06.2018, I. Belousov & I. Kabak leg. (Rd 5354 ZMUM), Akkari det. 2023, 2 males, China, NW Lijiang, W Chang J. NW Jinzhuang, 2.5 km N Tuozhi Vill, 27°09'32"N, 99°41'47"E, 2315 m, 17.05.2017, I. Belousov & I. Kabak leg. (Rd 5345 ZMUM), Akkari det. 2023.

Most similar to P. voluta especially in the distal part of the telopodite with two main folds and a strong hook-shaped median processes, but differs from the latter by the shape of the distal process, in posterior view subquadrate with a shallow notch (vs earlobe-shaped), the shape and position of the anterior lamella (at the basis of the distal part, rounded and serrated on the lower margin vs more distal and smaller).

Male with 68 PTs + telson. Length ca 60.5 mm. Live colour unknown. Preserved specimen with a general tawny dark brown, legs and antennae with a slightly fading colour but showing hints of dark sputter (Fig. 17A), prozona dark brown with paler alveolate spots (Fig. 17C, E); metazona dorsally dark brown, especially on crests, interrupted by larger irregular yellow alveolate spots on the lateral crests; colour gradually fading below the ozopores and ventrally. Head with dark pigmentation on the vertex and frons, mandibular stipes and gnathochilarium with yellowish spots, labral area paler (Fig. 17A, B). Fields of ommatidia subtriangular, composed of ~ 60 ommatidia in eight rows. Organ of Tömösváry large, situated close to and touching, anterior side of eye (Fig. 17A).

Head with a small projection on vertex (Fig. 17B). Leg-pairs 1 and 2 reduced and more setose than the rest, showing prefemoral and tarsal brushes (Fig. 17B), leg-pair 2 with a large dome-shaped anterior process on coxa and posterior gonopore (Fig. 17D), leg-pairs 3 and 4 with anterior triangular projections on coxa (Fig. 17D), leg-pair 6 with a small rounded mesal projection on coxa and a slight constriction of prefemur proximally on the posterior margin (Fig. 27A), leg-pair 7 with strongly modified coxa, anteriorly projecting in a large mesal slightly curved horn (Fig. 27B), trochanter with strong setae.

Gonopods. Parallel, distal solenomeral processes of telopodites crossing (Fig. 18A, B, D, E). Each gonopod with two asymmetrical clavate prefemoroidal processes, with pf1 broader and more setose than pf2 (Figs 18A, B, 19); coxa with a large rounded anterior lobe (Ca) and a smaller lateral one (Cl) (Fig. 19A); long and falcate mesal coxal process (b), reaching the distal part of the telopodite and distally projecting in a pointed tip (broken in the studied specimen). Telopodite (T) with a long and uniformly broad stem, distally abruptly expanding in an apically folded subquadrate plate, with, in posterior view, a slightly oblique and indented lateral margins (Fig. 18A), in anterior view (Fig. 18B) showing a darkly pigmented jagged lamella (dl) projecting antero-laterad (Fig. 18C–E), and a strong hook-shaped curved process pointing distad, gently narrowing towards its apex (Figs 18, 19) and bifurcating into the opening of the solenomere (s) and parasolenomere (ps).

Shangrila and Lijiang County, Yunnan, and Mangkang/Markam? County, Tibet Autonomous Region, China (Fig. 28).

The structures on the tip of the falcate mesal coxal process of the gonopod were also illustrated in the original description of P. viriosa by Wang and Zhang (1993) although never mentioned in the description of the species (Wang and Zhang 1993: 382, fig. 21).

2 males, 1 female, China, Sichuan Province, NW Pingchuan, 27°40'07"N, 101°44'04"E, 18.07.2011, I. Belousov & I. Kabak leg. (Rd 5346 ZMUM), Akkari det. 2023.

Most similar to P. viriosa in the shape of the distal part of the telopodite with two main folds and a strong hook-shaped median processes, differing in the earlobe-shaped distal process and the smaller and more distally located anterior lamella.

Male with 56PTs+Telson. Length ca 49.5 mm. Live colour unknown. Preserved specimen with a brownish general colour, legs and antennae dark brown (Figs 20, 21A), Head with dark pigmentation on the vertex and frons (Fig. 20B, C), mandibular stipes and gnathochilarium with yellowish spots. Fields of ommatidia subtriangular, composed of ~ 47 ommatidia in ten rows (Fig. 20B, C). Organ of Tömösváry very large, ~ 1.2 mm, situated close to and touching anterior side of eye (Fig. 20B). Prozona brownish sputtered with a paler colour; metazona dorsally dark tawny-brown, especially on crests, anterior part pale with brown alveolate spots (Fig. 20A, B).

Head with a protruding triangular projection on vertex (Fig. 20B, C, 21A). Leg-pairs 1 and 2 reduced and more setose than the rest, showing prefemoral and tarsal brushes, leg-pair 2 with a large anterior process on coxa and posterior gonopore (Fig. 21A), leg-pair 4 with anterior triangular projection on coxa (Fig. 21A), leg-pair 6 with one short triangular mesal process and a smaller lateral one on coxa, prefemur proximally slightly constricted on the posterior margin (Fig. 27C), leg-pair 7 with one mesal hyaline pointed process and a rounded projection surmounted by a similar but slightly smaller one, trochanter with a tuft of strong setae (Fig. 27D).

Gonopods. Parallel, slightly converging with the distal solenomeral processes of telopodites crossing (Fig. 21B–D). Each gonopod with two asymmetrical, short, clavate prefemoroidal processes with (pf1) broader and more setose than (pf2) (Figs 21B, C, 22); coxal anterior lobe lower than the lateral lobes low (Fig. 21C), long and falcate coxal process (b) reaching the distal part of the telopodite and apically pointed (Figs 21C, 22A, B, D). Telopodite (T) with a long stem, distally expanding in an earlobe shape with rounded lateral margin seen in posterior view (Fig. 21C, D), in anterior view as an oblique subtrapezoidal plate (Fig. 21B), with a transparent lamella (dl) attached on the lower part, marking and S-shape and serrated on the lower margin (Fig. 21B), mesal process curved upward, twisted and narrowing towards its apex (Figs 21B–D, 22A, B), bifurcating into the opening of the solenomere (s) and parasolenomere (ps).

This species was originally described from Ya Jang (= Jajiang) County, Sichuan, China. Here we add a new record from Yanyuan County which is ~ 250 km away in a straight line from the type locality (Fig. 28).

Although we have no doubt about the identity of the studied specimens, when comparing the gonopod of the new material in mesal view (Fig. 20D) with the drawing provided in the original description of P. voluta (Wang & Zhang, 1993: fig. 6), we noticed a few differences in the shape of the distal process of the telopodite, with the mesal process more twisted and curved, the anterior lamella more serrated and turned downwards, and the “s-twist” more obvious in our specimen (visualised with a rounded notch in mesal view).

Both available identification keys for the family Paracortinidae (Stoev and Geoffroy 2004; Liu and Tian 2015) mention eight or nine “macrosetae” on the small prefemoroidal process and use this character to separate the species from its congener P. leptoclada. However, in the specimens we examined, this number greatly exceeds that (see Figs 21, 22), proving that this character is not reliable for species discrimination.

Gonopods very similar to those in Paracortina zhangi. The species, can, however, be recognised by the presence of a spiniform mesal process on coxa 6, and a different shape of the coxa of leg 7 (Liu and Tian 2015).

(after Liu and Tian 2015) Species with 53–61 PTs + telson, general colour pale brownish yellow, head with a well protruding beak-shaped projection, ommatidia 21–32 in four irregular rows.

Head with a small beak-shaped projection on vertex (Liu and Tian 2015: fig. 23), PT6 strongly enlarged, leg-pairs 1 and 2 reduced and more setose than the rest, leg-pair 2 with a small anterior process and posterior opening of the gonopores, leg-pair 6 with a small pointed mesal process on coxa, leg-pair 7 with a mesal slender and pointed triangular process and a large rounded projection on coxa (Liu and Tian 2015: figs 30, 31), coxal sacs noticeable on leg-pairs 3–25.

Gonopods. Parallel, with a general slender aspect. Each gonopod with one prefemoroidal process that is clavate, slender, and setose (pf1), coxa with an anterior lobe and a short falcate mesal process (b) not reaching mid-length of the telopodite. Telopodite (T) broad at the base, gently narrowing distad, distal part dark with a lamella extending in a subtriangular fold, apically blunt and almost rounded, subapically more acuminate and the base slightly uneven, and a short slender bifurcated process, terminating in solenomere (s) and parasolenomere (ps).

Cave I, 24.875732°N, 105.150143°E, Yanchang Village, Tianshengqiao Town, Longlin County, Guangxi, South China (Fig. 28).

Very similar to P. zhangi (see below), differing mostly in the presence of small, pointed, mesal processes on coxae 6 in males and different shape of the coxa on leg-pair 7 (Liu and Tian 2015). The gonopods of the two species are strikingly similar but an accurate comparison is virtually impossible as the authors did not illustrate the gonopods in the exact same view.

Most similar to Paracortina yinae, from which it differs only in the absence of the spiniform process on the mesal side of coxa 6, different shape of coxa 7 (Liu and Tian 2015).

(based on Liu and Tian 2015) Species with 55–58 PTs +telson, general colour pale brownish yellow, head with a well protruding beak-shaped projection, ommatidia: 16–23 in four irregular rows.

Head with a large beak-shaped projection on vertex (Liu and Tian 2015: figs 1, 2), PT6 strongly enlarged, leg-pair1 and 2 reduced and more setose than the rest, leg-pair 2 with a small anterior process and posterior opening of the gonopores, leg-pair 6 with no modifications on coxa, leg-pair 7 with a protruding mesal triangular process and a very large subtriangular-rounded projection on coxa (Liu and Tian 2015: fig. 8), coxal sacs noticeable from leg-pairs 3–23.

Gonopods. Parallel, with a general slender aspect. Each gonopod with one clavate, slender, setose prefemoroidal process (pf1), coxa with an anterior lobe and a short falcate mesal process (b), not reaching mid-length of the telopodite (T). Telopodite broad at the base and gently narrowing distad, distal part dark with a transparent lamella (seen in lateral view; Liu and Tian 2015: fig. 9) extending in an apical fold, and laterally in a second one circling in part of the thin bifurcated branch terminating in solenomere (s) and parasolenomere (ps).

Cave Qiaoxia Dong 24°03.008'N, Rongdu Village, Qianxinan Zizhizhou, Ceheng County, Guizhou, southern China. The coordinates in Liu and Tian (2015) include a typo (24°03.008'N instead of 25°03.008'N), rendering the type locality appearing 100 km south of their locality description and map. In the distribution map (Fig. 28), we used the corrected coordinates.

The interpretation of the distal part of the telopodite remains tentative and rendered difficult as it is entirely based on the original description of the leg-pair 7 and gonopods (Liu and Tian 2015: figs 8–10, 15–18).

Scotopetalum warreni Shear, 2000.

Scotopetalum chinensis (Stoev & Geoffroy, 2004), comb. nov.; Scotopetalum warreni Shear, 2000.

Differs from Angulifemur by having parallel stems of telopodites; from Paracortina by the absence of large anteromedian subfalcate coxal process, and from the genus Crassipetalum gen. nov. by the much smaller prefemoroidal process/es and the very reduced subfalcate coxal process (b).

Shear (2000) described the genus Scotopetalum in the family Schizopetalidae, with the following diagnosis: “distinct from other genera of Schizopetalidae in lacking any indication of a sternum or coxal process in the gonopod, and in having no crest transition (full number of primary crests present on all segments). Each hemipleurite bears a series of five setae; all are in anterior position on segments 1–4, setae b, d, and e migrating posteriorly on segment 5, and all setae are posterior on segment 6.” The author doubted the validity of family Paracortinidae, which he believed could only have a status of subfamily within Schizopetalidae. He also interpreted the long falcate process typical for the family to be of a sternal origin.

In their review of the family, Stoev and Geoffroy (2004) described two new species of Paracortinidae from China and Vietnam, with the Chinese species (Paracortina chinensis) being quite similar to the species previously described by Shear (2000). The authors correctly noted this fact and compared the two species, highlighting the characters that distinguish them. They also synonymised Scotopetalum with Paracortina, considering the absence of a falcate coxal process and a second prefemoroidal process to be variable characters in the family. However, Stoev and Geoffroy (2004) failed to compare the structure of the telopodite in detail, which is quite specific in these two species. After a careful analysis, and now having much more material for comparison (including some of the Paracortina species described by Wang and Zhang 1993), we believe that Scotopetalum is a clearly defined morphological group and here we revive its original status.

Paratypes: 1 male, 2 subadult females, China, Yunnan Region, Zheng Xiong County, Liao Jun Don Cave (Touristic cave), millipedes collected close to rat corpse, 17.08.1999, J. & B Lips leg. (BG-NMNHS-INV-000000006262), Stoev det. April 2004.

Different from Scotopetalum warreni in the presence of a reduced mesal coxal process (vs absent in S. warreni), as well as the distal part of the telopodite. Also, in the number of ommatidia 30 ommatidia in five or six rows (vs 15 ommatidia in 6 rows), and by having 2+2 dorsal crests between poriferous crests (vs 6+6).

Corresponds to the description of the species as provided by Stoev and Geoffroy (2004); see also Figs 23, 24A, B.

Leg-pairs 1 and 2 reduced and more setose than the rest (Fig. 23B), leg-pair 2 with a small anterior process and posterior opening of the gonopores. Leg-pair 7 with a short mesal triangular process and a large, rounded projection on coxa, trochanter with a smaller, rounded projection covered with setae (Fig. 27G).

Gonopods. Parallel (Figs 24C, D, 25). One reduced, slender, and distally uniformly setose prefemoroidal process (less than half telopodite length) (pf1). Coxa with a very reduced anterior lobe (Ca) (Fig. 25A), mesally with a triangular lobe (a) and a rudimentary posterior tooth (b) (Fig. 24D, 25B, C). Telopodite (T) with a uniformly slender stem, gently curved, distally with a broad notch (n) separating a downturned bifurcated process (Fig. 24C, D, 25) bearing the solenomere (s) and parasolenomere (ps), overpassing a shorter anteriorly directed process (M), and a third flattened and acuminate process (k) emerging laterally.

Known from the caves Ke Ma Dong (Grotte du Brouillard Matinal), Liao Jun Dong (Tourist cave) and Da Hei Dong (Grande Grotte Noirre) in Zhen Xiong County, Yunnan, China.

Different from Scotopetalum chinensis in the complete absence of the mesal coxal process (vs a reduced tooth-shaped process in S. chinensis), as well as the distal part of the telopodite. Also, the presence of 15 ommatidia in three rows and 6+6 dorsal crests between poriferous crests.

Species with 53 PTs +telson, general colour yellowish-tan, head without modifications, 6+6 dorsal crests between poriferous crests, 15 ommatidia in three rows, pleurotergal setae 5+5, coxal sacs on legpairs 3–19, coxa 7 unmodified (meso-ventral thorns). Gonopods: parallel (based on Shear 2000: fig. 1). One reduced slender and distally uniformly setose prefemoroidal process (< ½ telopodite length) (pf1). Coxa with an anterior triangular coxal lobe (a). Telopodite (T) with a uniformly slender and gently curved stem, distally with a broad notch (n) separating an apical curved process pointing anteriad and a second downturned bifurcated process into solenomere (s) and parasolenomere (ps), overhanging a third flattened and acuminate process (k). At the level of the notch, a small hook-like process is inserted on the mesal side (Shear 2000: fig. 1, process ttp).

The species is only known from its original description thus not much can be said about its morphology nor the configuration of the gonopods in other views besides the lateral one (Shear 2000: fig. 1). Therefore, it remains unclear if the “hook-like basal process (ttp)” described for this species could actually be homologues with process (k) of Paracortina chinensis.

Caves at Hong Mat, Hoa Binh, Vietnam. In the distribution map (Fig. 28), we used the original coordinates as stated by Shear (2000).