Review of the millipede family Trichopolydesmidae in the Oriental realm (Diplopoda, Polydesmida), with descriptions of new genera and species

Abstract In the Oriental Region, the large, basically Northern Hemisphere family Trichopolydesmidae is shown to currently comprise 18 genera and 43 species. Based mainly on gonopod structure, all of them, as well as the whole family, are (re)diagnosed, including five new genera and seven new species. These new taxa are keyed, also being the first to be described from Indochina in general and from Vietnam in particular: Aporodesmella gen. n., with three species: A. securiformis sp. n. (the type species), A. similis sp. n. and A. tergalis sp. n., as well as the following four monotypic genera: Deharvengius gen. n., with D. bedosae sp. n., Gonatodesmus gen. n., with G. communicans sp. n., Helicodesmus gen. n., with H. anichkini sp. n., and Monstrodesmus gen. n., with M. flagellifer sp. n. In addition, Cocacolaria hauseri Hoffman, 1987, hitherto known only from New Ireland Island, Papua New Guinea, is redescribed based on material from Vanuatu whence it is recorded for the first time. One of the new genera, Gonatodesmus gen. n., provides a kind of transition or evolutionary bridge between Trichopolydesmidae and Opisotretidae, thus reinforcing the assignment of these two families to the single superfamily Trichopolydesmoidea.


Introduction
The large, chiefly Northern Hemisphere millipede family Trichopolydesmidae has recently been rediagnosed and, together with the much smaller, Oriental and Papuan family Opisotretidae , shown to compose the superfamily Trichopolydesmoidea, suborder Polydesmidea (Golovatch 2013). The bulk of trichopolydesmid diversity, both generic and species, is taken up by what has until recently been considered as an independent pantropical family Fuhrmannodesmidae. Hoffman (1980Hoffman ( , 1982 counted about 80 species from over 50 genera as unequivocally belonging to Fuhrmannodesmidae while another eight species in five genera were included in that family only provisionally. Because the present contribution focuses on the fauna of the Oriental realm alone, by default all tropical and subtropical Asian, plus the few known Papuan trichopolydesmids have hitherto been treated as fuhrmannodesmids. However, following the recent synonymization of Fuhrmannodesmidae and several other, smaller, Holarctic, Nearctic or Palaearctic families with Trichopolydesmidae (Golovatch 2013), the names "fuhrmannodesmids" or "Fuhrmannodesmidae" will be referred to here in quotation marks. Golovatch (1992Golovatch ( , 1994, when sorting out the rich "fuhrmannodesmid" fauna of the Neotropical realm, suggested the following evolutionary scenario. He accepted as the basalmost those genera showing rather small, subglobose gonopod coxae that form no significant gonocoel in which to hinge the largely exposed, usually rather simple and elongate telopodites. Moreover, as in some Holarctic Trichopolydesmoidea, the prefemoral (= setose) part of the gonopod is mostly orientated transversely to the body axis, extending fully mesally across the coxae. Following a series of transitional states, such forms ultimately culminate in having the gonopod coxae strongly enlarged, forming a large gonocoel in which to conceal the clearly shortened, usually highly complex and deeply sunken telopodites. Their prefemoral parts already tend to be positioned increasingly parallel to the body's main axis, thus providing a transition between the usually small-sized Trichopolydesmoidea (= so-called "micropolydesmoids") to the normally medium-to large-sized Polydesmoidea (= so-called "macropolydesmoids").
Naturally, similar general trends can be surmised to have occurred in the "fuhrmannodesmids" of the Afrotropical and, especially, Oriental realms, which also support fairly diverse faunas of this family. Prompted by the need to identify and allocate several species from Vietnam and Vanuatu, the present paper is an attempt to review all Oriental Trichopolydesmidae, i.e. 36 species or subspecies from 13 genera, arranged in alphabetic order:

Ootacadesmus humilis
We can also add here one more genus and species from the region concerned: 36. Cocacolaria hauseri Hoffman, 1987, the type species of Cocacolaria Hoffman, 1987, by original designation, described from New Ireland, Papua New Guinea by Hoffman (1987). He refrained from assigning it to a family, but placed it close to or inside the Haplodesmidae. Here we consider Cocacolaria as a genus of Trichopolydesmidae on account of body and gonopod structure, especially, the shape of the collum and second tergite, these being drastically different from those observed in Haplodesmidae (Golovatch et al. 2009a(Golovatch et al. , 2009b(Golovatch et al. , 2010. Furthermore, below we provide the first record of this species in Vanuatu. The following taxa must be excluded from Trichopolydesmidae or remain unclassified: 1. Glenniea Turk, 1945, with six species from the Himalayas of India, Nepal and Bhutan (Golovatch 1988a), as well as one species in Guangxi, southern China (Golovatch et al. 2012). A further two species, the first presumed troglobitic congeners, have been encountered in Sichuan, southern China (Golovatch & Geoffroy, in preparation). Hoffman (1980) listed this genus in Fuhrmannodesmidae, but Golovatch (1988a) transferred it to the Polydesmidae. 2. Typhlopygmaeosoma hazeltonae Turk, 1972, the type species of Typhlopygmaeosoma Turk, 1972, described from a cave near Shimla (formerly Simla), Himachal Pradesh, northern India (Turk 1972); first revised by Shear (1986) who equivocally assigned it to the family Opisotretidae, then by Golovatch (1988b) who placed it in the Polydesmidae.
In addition, closer unidentified "Fuhrmannodesmidae", provisionally referred to as Gen. sp. 1, Gen. sp. 2 and Gen. sp. 3, have been recorded in the Cat Tien National Park, southern Vietnam ). These species are described below.
As one can see from the above list, only one species, Pseudosphaeroparia cavernicola, is known too poorly (Turk 1945) to realistically become recognized. It is bound to remain enigmatic until a ♂ topotype has been obtained and properly described. In addition, Coonoorophilus monstruosus was based on a gynandromorph, thus strongly obscuring the identity both of the genus and species.
The main objective of the present paper is to address the generic classification of Trichopolydesmidae in the Oriental Region in order to identify and name a number of fresh samples from Vietnam and Melanesia.

Material and methods
Most of the material treated below was taken by Louis Deharveng, Anne Bedos (MNHN) and/or their collaborators in Vietnam. Several samples derive from ZMUM, collected by Alexander Anichkin (Joint Russia-Vietnam Tropical Center, Ho Chi Minh City, Vietnam) in a national park in southern Vietnam. SEM micrographs were taken using a JEOL JSM-6480LV scanning electron microscope. After examination, SEM material was removed from stubs and returned to alcohol, all such samples being kept in MNHN.
The course of the seminal groove was always checked and, if necessary, depicted using transmission light microscopy.

The main characters used in the classification of Trichopolydesmidae
The following characters have been used for defining genera in Oriental Trichopolydesmidae (= "Fuhrmannodesmidae"). Note that there is nothing particular in the peripheral, non-gonopod features that would uniquely characterize the Trichopolydesmidae (Golovatch 2011. The family-level differences tend to lie solely in gonopod conformation (see discussion below).

-Number of body segments
Like in most other families in Polydesmida, the number is 18, 19 or 20, largely being sex-characteristic. Thus, 20 segments in both sexes are known in most of the Oriental Trichopolydesmidae, 19 in both sexes only in Assamodesmus, Peronorchus, Aporodesmella gen. n., Gonatodesmus gen. n. and Helicodesmus gen. n., 19 in the ♂, but 20 in the ♀ in Cocacolaria, at least 19 in the ♂ of Coonoorophilus and Ootacadesmus. Deharvengius gen. n. is the sole genus in Trichopolydesmoidea which has only 18 segments in both sexes.

-Metatergal setae
All known species of Trichopolydesmidae show 3 transverse rows of tergal setae. The setation pattern is typical of the Polydesmidea, being 3+3 or more setae per row, only exceptionally 2+2 (Deharvengius gen. n.), plus 2 or 3 setae at each lateral margin. How ever, the setae themselves are typically ribbed, often helicoid, varying from long and sharp, like in Cocacolaria, Mastodesmus or Deharvengius gen. n., through short and simple, like in Nasodesmus or Ootacadesmus, to long and bacilliform, like in Assamodesmus, Deharvengius gen. n., Helicodesmus gen. n. or Gonatodesmus gen . n., or short and clavate, like in Magidesmus, Pseudosphaeroparia, Sholaphilus or some species of Aporodesmella gen. n. At least the bacilli-and claviform setae seem to always be modified, ribbed all along (e.g. Figs 11L,13L,M,16N,O). However, similar setae occur in some other families of Polydesmida such as Opisotretidae or Paradoxosomatidae (e.g. Golovatch et al. 2013).

-Metatergal sculpture
The pattern of metatergal sculpturing is typical of the Polydesmidea, i.e. 3 transverse rows of polygonal bosses or rounded tubercles, either with a more or less deep sulcus separating the first row from the two following ones or with clear sulci between all 3 rows. Each boss or tubercle is typically surmounted by a seta sometimes borne on a small knob. Among the Oriental Trichopolydesmidae, only very few species show truly distinct bosses or tubercles, e.g. Cocacolaria or Mastodesmus, whereas in the vast majority of cases the bosses are either flat or missing, and the transverse sulcus or sulci are largely superficial to wanting.

-Location and size of ozopores
Unlike species of Opisotretidae , Oriental Trichopolydesmidae usually show the ozopores small, opening flush on the dorsal surface and mostly located closer to the lateral margin of paraterga than to the caudal one. In Cocacolaria the ozopores are unusually prominent and, like in Hingstonia, Mastodesmus or Nasodesmus, placed just at or near the caudolateral paratergal corner. All other Oriental Trichopolydesmidae have the ozopores, albeit only rarely quite as large as in Kukkalodesmus, lying near the penultimate lateral incision of poriferous paraterga. So far as is known, the pore formula is always 5, 7, 9, 10, 12, 13, 15-17(18, 19), except in Aporodesmella gen. n., which is the sole genus in Trichopolydesmoidea which shows no ozopores whatever.
-Shape and size of paraterga Variation in the degree of development of paraterga is considerable, ranging from fully wanting (some species of Aporodesmella gen. n.), through very poorly developed (nearly missing in Cocacolaria, Peronorchus or Mastodesmus) to evident or strong (Nasodesmus, Magidesmus, Deharvengius gen. n. or certain species of Aporodesmella gen. n.), usually varying between species in speciose genera. As in the other Polydesmida, paraterga tend to be slightly underdeveloped and set lower in ♀♀ and juveniles compared to ♂♂.

-Antennae
Normally, the antennae in Trichopolydesmoidea tend to be geniculate between antennomeres 5 and 6, these segments also usually bearing conspicuous apicodorsal groups of bacilliform sensilla. However, in a few Oriental Trichopolydesmidae, e.g. Cocacolaria or Mastodesmus, this geniculation is either feeble or totally wanting. Only exceptionally is ♂ antennomere 6 supplied with a conspicuous dorsoparabasal stump (some species of Aporodesmella gen. n.).

-♂ head modifications
The ♂ vertex in Oriental Trichopolydesmidae, unlike that in some species from the Neotropical and Afrotropical realms (e.g. Golovatch 1994, Mauriès andHeymer 1996), usually remains unmodified. Only the ♂ of some species of Aporodesmella gen. n., as well as in Gonatodesmus gen. n. either shows a vertigial hump or the entire head in both sexes is clearly flattened dorsoventrally (Deharvengius gen. n.). Although the pre sence of such modifications is often considered as genus-characteristic (e.g. Mauriès and Heymer 1996), we believe they are only species-specific (e.g. Golovatch et al. 2013).

-Legs
Variation in leg length and armament in Oriental Trichopolydesmidae is quite pronounced, ranging from rather short and stout, sometimes also supplied with special ventral trichomes in the ♂, e.g. in some Hingstonia, to long and slender, e.g. in most of Hingstonia species, but the bulk of species show medium-sized, moderately to considerably stout legs which are usually devoid of modified trichomes in the ♂ and thus fail to differ much between the sexes. This contradicts Simonsen (1990) who stated that ♂ legs in "fuhrmannodesmids" show sphaerotrichomes. Only in Kukkalodesmus, Nasodesmus and Ootacadesmus does the ♂ have clearly inflated and elongated legs 3. Claw length seems to vary proportionately to leg length. In Gonatodesmus gen. n., ♂ tarsi 1 are supplied with modified, mostly bi-or trifid setae on the ventral side (Fig. 12B).

-Gonopod structure
In the systematics of any subgroup of the order Polydesmida, the gonopods offer most of the characters deemed useful, if not crucial, for the discrimination of genera and species. This fully applies to Trichopolydesmidae as well.
The gonopods in Trichopolydesmidae appear to vary much more strongly than in the Opisotretidae, the sole other family of Trichopolydesmoidea, in agreement with the fact that Trichopolydesmidae is much larger and is widespread throughout the Northern Hemisphere. Moreover, a gonopod-based diagnosis of Trichopolydesmidae is still not entirely satisfactory (Simonsen 1990, Golovatch 2011, 2013. This family appears to unite the micropolydesmoids in which the gonopod coxae are subglobose, from rather small to very large, while the prefemoral part is often orientated transversely to the body axis, usually extending fully mesally across the coxae. However, as the gonopod prefemora in trichopolydesmids grow shorter, the acropodites become orientated increasingly along the body axis, thus providing transitions to the superfamily Polydesmoidea . Simonsen (1990), in his cladistic analysis of the suborder Polydesmidea, allotted the Opisotretidae the rank of an independent superfamily, Opisotretoidea. He also distinguished the "Fuhrmannodesmidae" from the other "families" of Trichopolydesmoidea through the presence of a separate tooth (= solenomere) terminating the seminal groove. Even if a solenomere is present in some other trichopolydesmoids, it was said its position would not be apical.
Such a definition is basically correct, although a few Neotropical "fuhrmannodesmids" show no solenomere whatsoever (Golovatch 1994). The lack both of an accessory seminal chamber and a hairy pulvillus is typically also correct, but this is characteristic of nearly all Trichopolydesmoidea except Opisotretidae (at least as opposed to the Polydesmoidea). What is definitely wrong in Simonsen's (1990, p. 81) diagnosis of "Fuhrmannodesmidae" is the statement that the gonopod coxae, however large, fail to form a gonocoel, while the telopodite is devoid of a mesal branch (endomere). In contrast, according to Golovatch (1992Golovatch ( , 1994, the degree of development of the gonocoxae (and their gonocoel) seems to be instrumental in properly assessing the main evolutionary trends in the family. In addition, the gonotelopodite in various Trichopolydesmidae is usually supplied with additional branches or other outgrowths, including mesal ones.
Amongst the Oriental Trichopolydesmidae, like in the Neotropical ones (Golovatch 1992(Golovatch , 1994, the genera in which the gonopod coxae and their gonocoel are still relatively small, leaving the telopodites strongly exposed, can be viewed as the basalmost. This condition is characteristic of Assamodesmus, Cocacolaria or Mastodesmus. In Topalodesmus and some Sholaphilus, the gonopod coxa has a strong frontal (= anterior) process which, like a rather deep gonocoel, is deemed to provide additional protection to the clearly exposed telopodites. Similar conditions have been noted in some Neotropical "Fuhrmannodesmidae" as well (Golovatch 1992(Golovatch , 1994. The deepest, maximally developed gonocoel, where the telopodites are extremely low, fully sunken and supplied with a tooth-shaped solenomere at the bottom of a mesal hollow, is found only in Magidesmus. Most of the remaining genera seem to represent intermediate states, whereas such species-rich genera as Hingstonia, Pseudosphaeroparia and Sholaphilus show a degree of intrageneric variation. Only the gonopods of Gonatodesmus gen. n. stand apart in showing a kind of transition to Opisotretidae. Indeed, the gonocoel is small, the telopodites are strongly exposed and well separated, their basal parts are held parallel to the main axis, whereas their distal parts, following a clear midway geniculation, are directed abruptly laterad. Moreover, this genus demonstrates a strongly developed, hairy pulvillus and a small accessory seminal chamber so characteristic of most species of Opisotretidae (and Polydesmidae).

-Vulva
No special studies have been conducted on the conformation of the vulva in "Fuhrmannodesmidae". Turk (1945) provided a crude sketch of an elongate and strongly setose vulva in Pseudosphaeroparia cavernicola. Mauriès and Heymer (1996) illustrated a rather short and poorly setose vulva of a Sphaeroparia species from Uganda, tropical Africa. The epigynal crest has never been described in any Trichopolydesmidae. Because these structures are too small and inconspicuous in the samples we have examined, they have been omitted from the descriptions.

Generic reclassification
Based on the above information, as well as facing the need to properly allocate several new genera and species described below, we propose the following new diagnosis of Trichopolydesmidae and a new classification of the family's constituent Oriental genera.
Gonopods with subglobose, medially fused coxae, these being rather small to quite large (with correspondingly large gonocoel), micropapillate and at most only slightly setose laterally, sometimes with a frontal (= anterior) process, each supporting a cannula medially (exception: Caucasodesmus Golovatch, 1987, in which there is no cannula) and a sack-shaped to elongate telopodite. The latter ranging from stout and short, deeply sunken inside a deep gonocoel, to slender and long, nearly fully exposed, strongly to modestly curved caudad or mesad, only exceptionally geniculate (distal half directed abruptly laterad: Gonatodesmus gen. n.) or perforating coxal wall with a prominent process (Schizotelopus Verhoeff, 1941), usually complex, with various processes or outgrowths, sometimes fringed; seminal groove normally terminating distally or apically on a separate branch or tooth (= solenomere), rarely on a tooth inside gonocoel, exceptionally absent (Caucasodesmus). Typically neither an accessory seminal chamber nor a hairy pulvillus (a few exceptions, e.g. Gonatodesmus gen. n.).
Type genus. Trichopolydesmus Verhoeff, 1910. Remarks. Most of the above somatic and gonopod features of Trichopolydesmidae are in no way unique to the family, sometimes being also encountered, in various combinations, in the micropolydesmoid family Opisotretidae of the same superfamily Trichopolydesmoidea, as well as in certain macropolydesmoid members of the family Polydesmidae, superfamily Polydesmoidea , Golovatch 2013. The finely microspiculate limbus is also characteristic of most of the Polydesmidea, and is another feature whose importance was obviously overestimated by Simonsen (1990). It is only the gonopod structure that seems to be characteristic of Trichopolydesmidae, at least so to a certain extent. Superficially, female and/or juvenile trichopolydesmids from the Oriental realm are not or only barely distinguishable from the often sympatric or even syntopic female or juvenile Opisotretidae or smaller Polydesmidae.
Remarks. This well-defined Himalayan genus remains monobasic.
Remarks. This genus remains monobasic, its sole constituent species being quite widespread in Melanesia. C. hauseri is redescribed below, based on samples from Vanuatu. Diagnosis. 20 segments (♂, ♀); pore formula normal, ozopores lying opposite 3 rd incision, placed closer to lateral than to caudal margin of paratergite; ♂ vertex unmodified, paraterga keel-shaped, rather well developed, 3 rows of short, bacilliform to clavate setae on knobs; ♂ legs nearly normal, often with sphaerotrichomes; gonopod coxae from modest to large (gonocoel also from modest to deep), telopodites strongly exposed, usually massive, never fringed; sph (distal part of telopodite) complex, at least with one process or outgrowth, usually more; sl a rather long, simple, apical or subapical branch.
Remarks. This relatively species-rich, well-defined, Himalayan genus mostly contains relatively large species (up to 20 mm long).
Remarks. This monotypic genus seems to be rather poorly defined versus Sholaphilus, Pseudosphaeroparia, Coonoorophilus and Ootacadesmus, especially given the strong variation in gonopod structure in the relatively species-rich genera Sholaphilus and Pseudosphaeroparia (see also above and below).
Remarks. This small Himalayan genus is well-defined.
Remarks. This monobasic genus strongly resembles Peronorchus and Nasodesmus, but seems to be sufficiently well defined.
Remarks. This monobasic genus strongly resembles Peronorchus and Mastodesmus, but seems to be sufficiently well defined.
Remarks. This monotypic genus seems to be rather poorly defined versus Sholaphilus, Pseudosphaeroparia, Coonoorophilus and Kukkalodesmus (see also above and below).
Remarks. This genus strongly resembles Nasodesmus and Mastodesmus, but seems to be sufficiently well defined.
Remarks. This small genus is quite poorly defined versus Sholaphilus, Coonoorophilus, Ootacadesmus and Kukkalodesmus (see also above and below).

Sholaphilus Carl, 1932
http://species-id.net/wiki/Sholaphilus Diagnosis. 20 segments (♂, ♀); pore formula normal, ozopores placed closer to lateral than to caudal margin of paratergite; ♂ vertex unmodified, paraterga modest to well developed, 3 rows of short clavate metatergal setae; gonopod coxae very large (gonocoel deep) to modest, sometimes with a strong frontal process; telopodites rather deeply sunken and usually only little exposed, but sometimes rather strongly exposed, with or without parabasal processes; sph uni-to only faintly bipartite, with various outgrowths, densely fringed, sl a small apical or subapical tooth or branchlet.
Type species. Sholaphilus albidus Carl, 1932, by monotypy. Remarks. Even though this rather small genus is quite poorly defined versus Ootacadesmus, Pseudosphaeroparia, Coonoorophilus and Kukkalodesmus (see above), several species of Sholaphilus from the Himalayas have been described.
Remarks. This monobasic Himalayan genus is well-defined (see also below under Monstrodesmus gen. n.). Redescription. Length of adults of both sexes 4-6 mm (♂, ♀), width of midbody pro-and metazonae ca 0.3 and 0.4 mm, respectively. Coloration in alcohol from uniformly pallid to light yellowish.
Remarks. This species, originally described from a single ♂ taken in a cave in Lelet Plateau, New Ireland, Papua New Guinea (Hoffman 1987), appears to be common and widespread in Vanuatu. However, among the literally hundreds of specimens taken on Espiritu Santo and Malo islands by the famous SANTO 2006 expedition, held by the MNHN (Bouchet et al. 2009(Bouchet et al. , 2011(Bouchet et al. , 2012, there were only two adult males. This might be evidence of seasonality or partial parthenogenesis, or both. The original description is quite detailed and nicely illustrated (Hoffman 1987) and we are certain about the identity of our Vanuatu samples. We provide SEM images (Figs 1 and 2) to document the identity and to complement Hoffman's (1987) description.
Name. To emphasize the lack of ozopores, feminine. Type species. Aporodesmella securiformis sp. n., by present designation.

Remarks.
The new genus is unique among the Trichopolydesmoidea for its complete loss of ozopores. Among Oriental Trichopolydesmidae, Aporodesmella gen. n. seems to be especially similar to Peronorchus, sharing with it not only 19 body segments in both sexes, but also the gonopods demonstrating a modest gonocoel, elongate, clearly exposed and modestly curved telopodites which are (sub)contiguous medially and held parallel to each other (and to the main body axis), the solenophore being enlarged, more or less cup-shaped and membranous while the solenomere is a short subapical process or tooth. However, the prefemoral (= densely setose) part of the gonopod in Peronorchus is clearly shorter.
The following three new species are attributed to Aporodesmella gen. n. Name. To emphasize the axe-shaped solenophore. Diagnosis. Differs from congeners except A. similis sp. n. by the presence of a remarkable dorsoparabasal stump on ♂ antennomere 6, from A. similis sp. n. and other congeners by a peculiar, unusually short, axe-shaped solenophore and a simple, lanceolate, shorter and stout solenomere.
Gonopod aperture transversely oblong-oval, slightly subcordate, taking up most of ventral part of metazonite 7 (Fig. 4D). Gonopods (Fig. 4D-G) simple, with globose, scaly, medially fused coxae carrying a few setae on ventral face and a normal cannula mesally. Telopodites nearly straight, mostly exposed, in situ held parallel to each other, contiguous medially, largely unipartite due to prominent, rather densely setose prefemoral parts, rather short and stout, only distal quarter distinctly divided into a peculiar, axe-shaped, lateral solenophore (sph) and a smaller, anteriorly lying, sublanceolate solenomere (sl) directed slightly laterad. Seminal groove running entirely mesally, terminating on top of sl. Name. To emphasize the particularly strong similarity to the previous new species. Diagnosis. Differs from all congeners, except A. securiformis sp. n., in the presence of a peculiar, dorsoparabasal stump on ♂ antennomere 6, from A. securiformis sp. n. in the shape of the solenophore and solenomere.
Body moniliform, subcylindrical ( Fig. 5A-J), with 19 segments (♂). All characters as in A. securiformis sp. n. (Figs 5, 6A), except as follows. Gonopods (Fig. 6B, C) more complex, especially due to an elaborate and subtruncate tip of a more elongate and slenderer telopodite. Solenophore branch (sph) long, membranous, somewhat spoon-shaped, directed laterad, with a long, caudolateral, similarly membranous, subspiniform process (s) starting at base of sph and remaining coaxial with a prominent prefemoral portion. Mesal part of telopodite tip divided into 2 small horns (a and b) bearing a very small, dentiform solenomere (sl) lying in front and in between. Paratypes: 1 ♂, 1 ♀ (SEM), same locality, together with holotype. Name. To emphasize the well-developed paraterga. Diagnosis. Differs from congeners by well developed paraterga, short tergal setae, the ♂ also by the presence of a peculiar, central hump above the antennae, the laterally bent, beak-shaped solenophore and the absence of a solenomere. Description. Length of adults ca 4.0 mm, width of midbody pro-and metazonae 0.4 and 0.5 mm (♂). Coloration in alcohol uniformly pallid, tegument nearly translucent.
Gonopod aperture transversely oblong-oval, slightly subcordate, taking up most of ventral part of metazonite 7 (Fig. 8C). Gonopods (Fig. 8C-F) rather complex, with globose, microgranulate, medially fused coxae carrying a few setae on ventral face and a normal cannula mesally. Telopodites mostly exposed, in situ held parallel to each other, nearly contiguous medially, each unipartite, with a rather large, densely setose prefemoral part clearly set off from acropodite by an oblique ventral sulcus and a curved dorsal spine (k); acropodite divided into 2 subequally long parts, each also about equal in length to prefemoral portion; basal half of acropodite remaining coaxial with prefemoral portion, slightly broadened distad and carrying an evident orifice (o) of a fully mesally running seminal groove on a vestigial mesal solenomere (= tubercle), whereas distal half of acropodite, or solenophore (sph), acuminate, directed abruptly laterad, subflagelliform (b), carrying a parabasal apical tooth (t) and a conspicuous, curved, denticulate lamina (a) beginning from near o and turning around b on lateral side.
Remarks. This species served elsewhere  to illustrate a somewhat transitional condition in its gonopod structure, especially an elongate and laterad directed apical part, between the Trichopolydesmidae (= "Fuhrmannodesmidae") and Opisotretidae within the same superfamily Trichopolydesmoidea. A far more spectacular example of the same trend is seen in Gonatodesmus gen. n. (see below).
Name. To honour Louis Deharveng (MNHN), one of the principal collectors, masculine.
Remarks. In having only 18 body segments, this new genus is almost unique amongst the Trichopolydesmoidea. The same segment counts seem to solely concern Moojenodesmus pumilus Schubart, 1944, only one of the species of the rather small Neotropical genus Moojenodesmus Schubart, 1945, from the same fami ly Trichopolydesmidae; M. pumilus is especially minute (< 2.5 mm long), and it seems to be parthenogenetic and quite widespread in Brazil (Golovatch 1992(Golovatch , 1994. Among the Oriental Trichopolydesmidae, partly globally as well, Deharvengius gen. n. stands well apart also in having a less convex head, only 2+2 tergal setae per row and very unusual gonopods. The latter are long, simple, unipartite, strongly curved and crossing medially, thus being quite similar to the condition observed in Cocacolaria (Fig. 2B-E). Yet in Deharvengius gen. n. the gonopods are much more strongly appressed to the venter while the seminal groove runs mostly on the ventral = lateral (not mesal) side to terminate apically on a simple and slender (not at about midway on a stout and calyciform) solenomere. By its habitus and even gonopod structure, Deharvengius gen. n. resembles some Euro-Mediterranean genera of Trichopolydesmidae as well (see reviews by Mauriès (1983) and Golovatch et al. (2013)). Some of them show a deeply bipartite and strongly curved gonopod telopodite, the prefemoral part of which is quite elongate, but lies more or less transversely to strongly angular, largely (sub)parallel telopodites and extends across the nearly entire ventral width of segment 7. Such are Trichopolydesmus Verhoeff, 1898 (together with the subgenus Banatodesmus Tabacaru, 1980), Bacillidesmus Attems, 1898, Napocodesmus Ceuca, 1974and Caucasodesmus Golovatch, 1985. In contrast, the gonotelopodites in Verhoeffodesmus Strasser, 1959, Cottodesmus Verhoeff, 1936and Occitanocookia Mauriès, 1980 have increasingly shortened prefemoral parts, being enlarged and laterally flattened distad and unipartite, but mostly less strongly curved, in Cottodesmus and Occitanocookia also devoid of a solenomere, but sometimes supplied instead with what can be seen as a primordial accessory seminal chamber. In Trichopolydesmus, Heterocookia Silvestri, 1898, Ingurtidorgius Strasser, 1974and, especially, Mastigonodesmus Silvestri, 1898, the solenomere is almost to fully flagelliform, branching off near the base of the femorite. In all these genera, the gonotelopodites are strongly exposed, not sunken inside an obvious gonocoel .
Gonopod aperture transversely oblong-oval, taking up most of ventral part of metazonite 7 (Fig. 10C-E). Gonopod coxae with gonocoel not deep; telopodites clearly exposed, but lying tightly appressed and parallel to venter, strongly curved, semi-circular, unipartite, slender, directed mesad and strongly overlapping; prefemoral parts about half as long as telopodites, set off from acropodites neither by a sulcus nor a cingulum; each acropodite with a small solenophore (sph) lying basal to a spiniform, apical solenomere (sl). Seminal groove running mostly along ventral (= lateral) surface of a subbasally obviously twisted acropodite.
Remarks. This new genus is highly disjunct in being the sole member of the family which shows a remarkable midway geniculation of the gonopod telopodite. The gonopod tip being directed laterad is not unique in Trichopolydesmidae, shared also with Aporodesmella tergalis sp. n. However, the entire distal, post-geniculation half of the gonopod in Gonatodesmus gen. n. is obviously twisted and strongly elongate, also sho wing a remarkably distinct hairy pulvillus on top of a small, but evident accessory seminal chamber. Only vestiges of the latter are occasionally observed in a couple of Euro-Mediterranean genera of Trichopolydesmidae (Golovatch 2013), whereas an obvious hairy pulvillus seems to be singular in the family. In contrast, such a gonopod conformation vividly resembles the conditions largely characterizing the family Opisotretidae , but the prefemoral parts in Gonatodesmus gen. n. are clearly elongate and held parallel to the main axis while the acropodites distal to the unique geniculation are yet relatively short to be directed dorsolaterad. So the assignment of Gonatodesmus gen. n. to Trichopolydesmidae, not Opisotretidae, is preferred. However, one may justly regard Gonatodesmus gen. n. as a kind of transition or bridge between these two families of Trichopolydesmoidea. This new genus rather demonstrates an evolutionary trend from the more basal Trichopolydesmidae towards the advanced Opisotretidae. Name. The species epithet refers to the gonopod conformation somewhat transitional between the families Trichopolydesmidae and Opisotretidae.
Gonopod aperture transversely oblong-oval, taking up most of ventral part of metazonite 7 (Fig. 12D). Gonopod coxae (Fig. 12D-G) rather small (gonocoel not deep), sparsely setose and clearly micropapillate laterally, each with a subtriangular ventral projection (x); telopodites clearly exposed, but lying rather tightly appressed and parallel to venter, unipartite, slender, abruptly geniculate and directed laterad distal to prefemoral parts, the latter about half as long as telopodites, held parallel to main axis, each with an apicomedian field of strong curved spines (d), set off from a twisted acropodite by a strong geniculation cingulum (c); acropodite elongate, near midway with a remarkably large hairy pulvillus (p) on top of a small accessory seminal chamber; acropodite distal to pulvillus particularly slender, slightly curved caudad, subacuminate; neither a separate solenophore branch nor a solenomere. Seminal groove (sg) running mostly on mesal side, turning caudad (= ventrad) only beyond geniculation.
Remarks. This new genus is remarkable within Trichopolydesmidae in showing particularly strongly twisted gonopods, including their prefemoral parts, such that the seminal groove turns ca 180° around the highly complex transverse acropodite. Also noteworthy is the complete lack of a solenomere. Name. To honour Alexander E. Anichkin, who provided for study all millipede material he had collected in Cat Tien National Park, including three trichopolydesmids described here.
Body with 19 segments (♂, ♀). Tegument dull, texture of nearly entire body delicately alveolate to scaly, only sterna nearly smooth (Fig. 13A-I). Head very densely and finely pilose; epicranial suture highly superficial; genae squarish ( Fig. 13A, D, G, K); gnathochilarium rather broad, sparsely and uniformly setose (Fig. 13K); isthmus between antennae about 1.2-1.3 times as broad as diameter of antennal socket (Fig. 13G, K). Antennae short (Fig. 13A, D, G), reaching only behind collum when stretched dorsally, not geniculate, rather strongly clavate due to a particularly enlarged antennomere 6, the latter with a usual, tight, distodorsal group of numerous, bacilliform sensilla; a similar, but smaller, also distodorsal group of sensilla on antennomere 5; antennomere 7 with a smaller distodorsal group of only a few shorter and curved sensilla in front of a tiny mid-dorsal knob.
Gonopod aperture transversely oblong-oval, taking up most of ventral part of metazonite 7 (Fig. 14A). Gonopod coxae rather small (gonocoel not deep), sparsely setose and clearly micropapillate laterally (Figs 14,15); telopodites quite well exposed  and unusually transverse, but stout and remarkably complex, very strongly twisted, partly fimbriate(curved ventral projections c1 and c2) or plumose (a long lateral process k), with several outgrowths of varying shapes (a stump-shaped, rounded, mesal i and 2 indistinctly separated, densely microdentate, also rounded m and l); prefemoral part about half the height of telopodite, demarcated on lateral (not medial!) side by an oblique seminal groove running further mesad onto a medioventral outgrowth of acropodite to terminate distally at joint base of c1 and c2, with neither a solenomere nor an accessory seminal chamber, nor a pulvillus.
Name. To emphasize the monstrously long flagellum of the gonopod, masculine. Type species. Monstrodesmus flagellifer sp. n., by present designation.
Remarks. This new genus seems to be particularly similar to Topalodesmus Golovatch, 1988, monobasic, from the Himalayas of India (Golovatch 1988b). Indeed, both share basically the same gonopod conformation: coxae quite massive; gonocel rather deep, but telopodites clearly exposed, deeply tripartite, untwisted, curved caudad, subcontiguous medially and held parallel to main axis; seminal groove running entirely mesally along a very strong frontal endomere branch (= solenomere, sl). However, the differences are definitely significant enough to keep these two genera separate. Unlike Topalodesmus which shows 20 segments in both sexes, the gonopod coxa in Monstrodesmus gen. n. is devoid of a frontal process, the exomere (ex) prominent (vs vestigial), the caudomesal branch (fl) unusually long and flagelliform (vs thick and unciform) while the solenomere (sl) a very long, strong, frontal branch. Paratype: 1 ♂ (SEM), same locality, together with holotype. Name. The species epithet, a noun in apposition, is to emphasize the remarkably long gonopod flagellum.
Body with 19 segments (♂). Tegument dull, texture of nearly entire body delicately alveolate to scaly, only sterna nearly smooth (Fig. 16A-I). Head very densely and finely pilose; epicranial suture highly superficial; genae squarish ( Fig. 16A, D, G); gnathochilarium rather broad, sparsely and uniformly setose (Fig. 16K); isthmus between antennae about 1.2 times as broad as diameter of antennal socket (Fig. 16G). Antennae short (Fig. 16G, L), reaching only behind collum when stretched dorsally, not geniculate, rather strongly clavate due to a particularly enlarged antennomere 6, the latter with a usual, tight, distodorsal group of numerous, bacilliform sensilla; a similar, but smaller, also distodorsal group of sensilla on antennomere 5; antennomere 7 with a smaller distodorsal group of only a few shorter and curved sensilla in front of a tiny mid-dorsal knob.
Gonopod aperture transversely obcordate, taking up most of ventral part of metazonite 7 (Fig. 17C, E). Gonopod coxae large (gonocoel rather deep), with 2 long setae and clearly micropapillate laterally, but without any frontal outgrowths 18); telopodites quite well exposed, not twisted, tripartite, elongate, moderately curved caudad, subcontiguous medially and held parallel to each other; acropodites lying distal to prefemoral parts much longer than and coaxial with the latter; solenomere (sl) (= endomere) a strong, simple, frontal branch about as long as an apically bifid lateral exomere (ex); an extremely long, flagelliform, mesal branch (fl) at base of both sl and ex; seminal groove (sg) running entirely along mesal side of sl to terminate on top with neither an accessory seminal chamber nor a pulvillus.
A key to genera and species of Trichopolydesmidae currently known from Vietnam/Indochina, based mainly on male characters Since brief diagnoses of all previously known Oriental trichopolydesmid genera are given above, and their scopes and statuses also considered, below we only present a key to the new genera and species, the first to be reported from Indochina in general and from Vietnam in particular. Janvier) in 2005, 2006 and 2008; the field work was carried out in collaboration with the Institute of Tropical Biology and the National University of Ho Chi Minh City.
Special thanks go to Robert Mesibov, Cathy Car and a third, anonymous reviewer who kindly provided very important critiques and suggestions to improve the paper.