Iulomorphid millipedes (Diplopoda, Spirostreptida, Iulomorphidae) of Tasmania, Australia

Abstract Tasmanian Iulomorphidae are here assigned to the genera Amastigogonus Brölemann, 1913, Atelomastix Attems, 1911 and Equestrigonus gen. n. Descriptions or redescriptions are given for Amastigogonus danpicola sp. n., Amastigogonus elephas sp. n., Amastigogonus fossuliger Verhoeff, 1944, Amastigogonus hardyi (Chamberlin, 1920), Amastigogonus hellyeri sp. n., Amastigogonus michaelsae sp. n., Amastigogonus orientalis sp. n., Amastigogonus peninsulensis sp. n., Amastigogonus tasmanianus Brölemann, 1913 (type species of Amastigogonus), Amastigogonus verreauxii (Gervais, 1847), Atelomastix bonhami sp. n., Atelomastix smithi sp. n. and Equestrigonus tasmaniensis gen. n., sp. n. The synonymy of Amastigogonus nichollsii Verhoeff, 1944 with Amastigogonus hardyi is accepted, and lectotypes are designated for Amastigogonus nichollsii and Amastigogonus tasmanianus.


Introduction
In Tasmania, Australia, native species of Spirostreptida are found at all elevations and in most natural habitats, although they are rarely seen in coastal dune scrubs or in grasslands and moorlands. Spirostreptidans can be abundant in native forest and in Eucalyptus and Pinus radiata plantations. For example, spirostreptidans made up 65% (Mesibov 1993) and 48% (Mesibov 1998) of all millipedes collected in two of the author's hand-sampling studies in wet eucalypt forest and cool temperate rainforest. Spirostreptida include Tasmania's longest millipedes (Fig. 1A) and are well-known to many Tasmanian naturalists for the strong smell of their benzoquinone defensive secretions.
In the present study A. fossuliger, A. hardyi, A. tasmanianus and A. verreauxii are redescribed, lectotypes are designated for A. nichollsii and A. tasmanianus, and six new Tasmanian species are added to Amastigogonus. I also describe two new Tasmanian species of Atelomastix Attems, 1911, a genus previously known only from mainland Australia, and I propose a new genus for a distinctive iulomorphid species which is widespread and locally abundant in the north of Tasmania's main island.

Materials and methods
While preparing this paper I supplemented material in the collections of the Queen Victoria Museum and Art Gallery and the Tasmanian Museum and Art Gallery with fresh specimens from selected localities. Iulomorphid millipedes were hand collected in or under woody litter during the day, as well as on tree trunks at night.
In descriptions of individual spirostreptidans I follow Enghoff et al. (1993) in counting trunk rings by excluding the telson and giving podous + apodous ring counts, e.g. "(55+1) rings", and I give the count ranges I observed rather than count frequencies. In Atelomastix species, the three branches of the anterior gonopod are here called sclerites "a", "b" and "c", following  and Edward and Harvey (2010). Amastigogonus species descriptions only include diagnostically relevant features and the genus description for Amastigogonus should be consulted for other details.
Long-preserved Spirostreptida are often deeply stained and made brittle by defensive secretion, and it is difficult to dissect such specimens to examine gonopods without breaking the rings adjoining the gonopod aperture. However, Amastigogonus males usually have everted gonopods when first killed by freezing, then submerged in tap water for several hours at room temperature (Fig. 1B, C). I used this procedure to prepare some fresh Amastigogonus specimens for examination and description.  Verhoeff, 1944. A Living male on author's palm, later preserved in QVM 23:54468 B Long-preserved male with retracted gonopods, ex QVM 23:54290 C Male with gonopods everted after freeze-killing and soaking in water, ex QVM 23:54468. Scale bars: A = 10 mm, B, C = 5 mm.
Another methodological problem is that the pseudoflagellum on the anterior gonopod of several Amastigogonus species is remarkably thin and fragile. In this paper I provide gonopod drawings rather than scanning electron micrographs, as the SEM facility to which I have access does not have a critical-point dryer, and even brief drying can damage or distort an Amastigogonus pseudoflagellum.
Dissected gonopods and other body parts were first cleared in 80% lactic acid, then temporarily mounted in 1:1 glycerine:water and imaged using an eyepiece video camera mounted on an Amscope binocular microscope. Preliminary drawings of cleared parts were traced from printed copies of images. Drawings were then edited by reference to the actual part.
Photomicrographs were taken with a Canon EOS 1000D digital SLR camera mounted on a Nikon SMZ800 binocular dissecting microscope equipped with a beam splitter. Measurements were made to the nearest 0.1 mm with the same microscope using an eyepiece grid and a reference scale. Photomicrographs used in the figures are focus-stacked composites prepared with Zerene Stacker 1.04.
Plates were composed using GIMP 2.8. Backgrounds in some photomicrographs have been edited to remove distracting highlights and artifacts. Maps were drawn with QGIS 2.4.
Diagnosis. Like Victoriocambala Verhoeff, 1944 in having the coxite process on the anterior gonopod close to the telopodite and nearly as long, forming a chamber resembling a bird's beak in which the pseudoflagellum is protected. Differences between Amastigogonus/Victoriocambala, as noted by Jeekel (2009: 35), are leg 1 with free/fused tibia and tarsus, posterior gonopod without/with reduced telopodite.
Description. Living animals usually with black or dark grey rings with annular pale band at rear of each metazonite, often with a greenish tinge (live A. fossuliger more consistently green, see species description); head, collum and telson often faintly reddish brown; legs pale. With long storage in alcohol and staining by defensive secretion, animals dull grey with faintly reddish legs.
Female slightly larger in diameter than male with same ring count; leg 1 normally leg-like, claw-bearing; no prefemoral pads on any legs.
Remarks. Amastigogonus species are closely similar in size, general appearance and habits, and males can only be positively identified by close inspection, and usually dissection, of the anterior gonopods. There is also some variation in non-gonopodal male structures, as noted here and in the species descriptions. The most reliable of these differences are in cardo shape and modifications of near-aperture legs: Cardo. In A. danpicola sp. n. the cardo extends further ventrally in its posterior half than in its anterior half, i.e. the cardo is deeper posteriorly (Fig. 4A). In other Amastigogonus species the ventral edge of the cardo is either evenly convex or is deeper anteriorly (Fig. 4B).
Other differences between species do not seem to be large enough or consistent enough to be useful for taxonomic purposes: Legpair 1. The relative lengths and widths of the leg 1 podomeres vary a little between species (Fig. 4C-G), between individuals, and sometimes between right and left legs.
Prefemoral pads. There are differences between species in pad length, as shown in Fig. 5A and 5B (pa), but these differences are masked by the anteroposterior size gradient on single individuals as well as by variability from individual to individual.
Metazonal striae. The height reached by the horizontal striae on the metazonites diminishes slightly from anterior to posterior. At ca 2/3 body length, the topmost horizontal stria lies at ca 1/2 or ca 3/4 of the height to the ozopore ( Fig. 5C; st), depending on species, but with considerable variation between rings and between individuals. Diagnosis. Coxite process of the anterior gonopod divided by narrow fossae apically and anterobasally; legs 6, 7, 10 and 11 with elongated coxae.
Distribution. Eucalypt forest over ca 1000 km 2 on the East Coast of Tasmania, mainly in the Apsley, Douglas, St Pauls and Swan River catchments (Fig. 7C), from near sea level to at least 600 m. Possibly parapatric with A. elephas sp. n. in the upper St Pauls River catchment and with A. michaelsae sp. n. near Swansea. Sympatric with A. fossuliger and with A. orientalis sp. n.
Name. Abbreviation in lower case "danp" for Douglas-Apsley National Park plus Latin cola, inhabitant; noun in apposition. This species is abundant in the Park, which also contains the type locality.
Remarks. A. danpicola sp. n. is the most apomorphic species within the group included here in Amastigogonus. I place it in this genus because the structure and position of the pseudoflagellum and its supporting setae conform to the general pattern seen in the other Amastigogonus species. Other material. 6 males from 5 unique localities; details in Suppl. material 1. Diagnosis. Like A. verreauxii in having a telopodite with a subquadrate extension of the posterobasal margin and a posteriorly curving pseudoflagellum; distinguished from A. verreauxii in the pseudoflagellum having a small, tooth-like, distally directed extension basal to the posterobasally directed tip.
Distribution. Eucalypt forest at the eastern end of the Fingal Valley on the Tasmanian East Coast (Fig. 7C), to at least 700 m elevation. The small range of this species is home to other locally endemic invertebrates, including the millipede Tasmaniosoma nicolaus Mesibov, 2015 6B) is similar to that of A. verreauxii (Fig. 8D). The wide disjunction in the species ranges (more than 100 km) and the remarkable consistency of form in the anterior gonopod of A. verreauxii (across a linear range extent of ca 400 km) suggests that the two lineages have long been separated. Syntypes. At least 1 male and 1 female, Lake Leake, Tasmania, date and collector unknown (see Remarks, below), specimens not located. Other material. 130 males and 12 females from 66 unique localities; details in Suppl. material 1.

Amastigogonus fossuliger
Diagnosis. Coxite process of anterior gonopod with posterodistal margin not extended; pseudoflagellum with dense field of short setae on telopodite behind pseudoflagellum tip; pseudoflagellum with distinct shoulder, the prostatic groove making an S-bend before entering the abruptly tapered tip of the pseudoflagellum.
Coxite process on anterior gonopod ( Fig. 6C) with posterodistal margin not extended and folded over laterally. Telopodite with single row of prominent setae on posterior side of medial thickening to near telopodite apex, the thickening then widening and bearing dense brush of numerous minute setae. Pseudoflagellum ca 1/2 width of telopodite at base, tapering abruptly at ca 1/2 pseudoflagellum height to narrow, sharply pointed tip with rounded shoulder on anterior side of tapered section ( Fig.  3C; ps), sometimes with small, tooth-like, anterodistal extension on shoulder; prostatic groove ( Fig. 3C; pg) making S-bend from anterior side of pseudoflagellum into tapered tip.
Distribution. Widespread in the eastern half of Tasmania (Fig. 7B) in dry and wet eucalypt forest from near sea level to at least 1050 m, extending across the Central Plateau to the Cradle Mountain area. Parapatric with A. hellyeri sp. n. along the Mersey Break, a well-documented faunal divide for millipedes in north central Tasmania  (Mesibov 1999). Co-occurs with A. tasmanianus in northeast Tasmania. Overlaps with A. verreauxii on the Central Plateau and possibly in southern Tasmania, and to a small extent with A. danpicola sp. n. southeast of the Fingal Valley. The far southern record on the distribution map (Fig. 7B) is for two A. fossuliger males found on the verandah of a house at Francistown, and may represent an accidental translocation rather than a natural occurrence. Remarks. At least one male and one female of this species from the Lake Leake area were probably sent to Verhoeff by George Edward Nicholls, a Western Australian biologist who collected in Tasmania in 1928, 1929and 1939(Nicholls 1943. Verhoeff (1936: 14) had previously thanked Nicholls for providing specimens of an unrelated millipede species from Lake Leake.
I have trouble understanding the differences in the two anterior gonopods illustrated by Verhoeff (1944), both presumably from Lake Leake specimens and possibly from the same male. Verhoeff's fig. 6 shows a right gonopod tip in posterior view, fig. 7 a left gonopod tip in medial view. The thread-like pseudoflagellum in fig. 6 has a tooth-like extension on the shoulder and an intact posterobasal margin, while the shorter, tapered pseudoflagellum in fig. 7 has no tooth-like extension and a notched posterobasal margin. The remarkable thinness and fragility of the A. fossuliger pseudoflagellum may be the explanation for Verhoeff's difficulties in seeing and drawing these features. My Fig. 6C is based on a male from near the type locality, while the image in Fig. 3C is of a male from Ansons Bay, ca 100 km to the north. The only significant difference is the absence of a tooth-like extension in the latter.
Other material. 3 males and 3 females from 2 unique localities; details in Suppl. material 1.
Diagnosis. Like A. fossuliger in having the pseudoflagellum with a narrow, tapering, pointed tip; distinguished by the prostatic groove following a straight course on the pseudoflagellum rather than having an S-bend, and by the lack of a dense field of short setae on the telopodite behind the pseudoflagellum tip.
Coxite process on anterior gonopod (Fig. 6D) with small portion of posterodistal margin extended as rounded tab and folded over laterally. Telopodite with single row of prominent setae on posterior side of medial thickening and short row on anterior side near apex. Pseudoflagellum ca 1/2 telopodite width at base, slightly extended posteriorly at base, then gradually tapering to sharp, posterodistally directed point.
Distribution. Currently known only from eucalypt forest at two sites in the Hobart metropolitan area (Fig. 7B) , -1917, (Marks 1991. Hoffman (1972) examined and illustrated the E. hardyi holotype and assigned the species to Amastigogonus. The locality given for the types is simply "Tasmania" (Hoffman 1972: 204). Chamberlin (1920: 166-167) did not specify the number or gender of the E. hardyi paratypes.
Other material. 142 males and 10 females from 26 unique localities; details in Suppl. material 1.
Diagnosis. Like A. orientalis sp. n. in having a broad pseudoflagellum abruptly reduced apically; distinguished by having a smoothly curving rather than a subquadrate extension of the posterobasal telopodite margin, with a notch anteriorly at the base of the reduced pseudoflagellum tip and the tip relatively long and curving laterally or medially.
Coxite process on anterior gonopod ( Fig. 6E) with posterodistal margin extended as rounded tab and sharply folded over laterally. Telopodite with single row of prominent setae on posterior side of medial thickening. Pseudoflagellum ca 2/3 telopodite width at base, posterior margin sometimes sinuous in transverse plane; abruptly narrowing apically with a shallow notch dividing the apex into small, rounded, anterior tooth and short, thinly laminar, acutely pointed extension, the latter usually folded over laterally and carrying the prostatic groove to its pointed tip.
Distribution. Eucalypt forest and cool temperate rainforest in northwest Tasmania (Fig. 7B), from near sea level to at least 760 m. Meets A. fossuliger parapatrically along the Mersey Break (Mesibov 1999) and overlaps to a small extent in far northwest Tasmania with A. verreauxii.
Name. For Henry Hellyer (1790-1832), explorer of northwest Tasmania; noun in the genitive case.
Remarks. The tip of the pseudoflagellum in preserved males is often bent laterally into the space between the pseudoflagellum and the rest of the telopodite, as shown in Fig. 6E. In other specimens it may be bent medially towards the coxite tip, or extend past the tip of the telopodite. This species otherwise varies little across its range. Other material. 11 males and 1 probable female from 8 unique localities; details in Suppl. material 1.

Amastigogonus michaelsae
Diagnosis. Like A. peninsulensis sp. n. in having a relatively broad, gently tapering pseudoflagellum; distinguished by the pseudoflagellum tip directed distally rather than posteriorly and with a prominent, posterodistally directed tooth basally on the posterior margin.
Coxite process on anterior gonopod (Fig. 6F) with posterodistal margin not extended and folded over. Telopodite without pronounced medial thickening, but with usual row of setae from near posterior margin to midline at telopodite apex, continued basally as group of sparse setae (not shown in Fig. 6F) behind tip of pseudoflagellum. Pseudoflagellum ca 1/3 telopodite width at base, curving slightly posteriorly and tapering gradually to rounded, posteriorly directed apex, and with short, sharp, posterodistally directed tooth at ca 1/4 pseudoflagellum height on posterior margin.
Distribution. Eucalypt forest in southeast Tasmania from Coles Bay south to the Nugent area, including Maria Island (Fig. 7C), from sea level to at least 590 m. Possibly parapatric with A. danpicola sp. n. near Swansea, parapatric or overlapping with A. orientalis sp. n. west of Triabunna.
Name. For the ecologist Karyl Michaels, who trapped specimens in the previously little-sampled dry forests of southeast Tasmania; noun in the genitive case.
Remarks. Most of the non-type males are partial or fragmented specimens. Other material. 14 males and 3 probable females from 14 unique localities; details in Suppl. material 1.

Amastigogonus orientalis
Diagnosis. Like A. hellyeri sp. n. in having a broad pseudoflagellum abruptly narrowed apically; distinguished by having a subquadrate extension of the posterobasal telopodite margin, with the prostatic groove opening on a very short toothlike extension of the reduced pseudoflagellum tip, rather than on a relatively long, flexible extension.
Coxite process on anterior gonopod (Fig. 8A) with posterodistal margin substantially extended as rounded tab and folded over laterally to ca 1/2 process width. Telopodite with posterobasal surface produced posteriorly as large rounded flange ( Fig. 8A; fl) and with single row of prominent setae on posterior side of medial thickening. Pseudoflagellum ca 1/2 width of telopodite at base, expanded slightly posteriorly, tapering gradually before expanding distally in wedge shape, often curving laterally, with very short pointed extension at middle of distal margin; prostatic groove making S-bend from anterior side of pseudoflagellum into tip, terminating in pointed extension. Posterior margin of pseudoflagellum sometimes sinuous in transverse plane.
Distribution. Eucalypt forest over ca 100 km linear extent in the Eastern Tiers of Tasmania (Fig. 7A) from ca 150 to at least 600 m elevation; the disjunction in the distribution map is likely to be a sampling artefact. Possibly parapatric with A. elephas sp. n. near Gray; overlapping to a small extent with A. danpicola sp. n. in the Douglas-Apsley National Park and with A. fossuliger northwest of Triabunna; parapatric or overlapping with A. michaelsae sp. n. in the southern Eastern Tiers.
Name. Latin orientalis, eastern; adjective. This species is restricted to the East Coast region of Tasmania. Paratypes. 13 males and 5 females, details as for holotype, QVM 23:54545. Other material. 3 males and 1 female from 3 unique localities; details in Suppl. material 1.

Amastigogonus peninsulensis
Diagnosis. Like A. michaelsae sp. n. in having a relatively broad, gently tapering pseudoflagellum, but with the tip directed distally and without a prominent tooth on the posterior margin.
Coxite process on anterior gonopod (Fig. 8B) with very small portion of posterodistal margin slightly extended as rounded tab, bent laterally rather than folded over. Telopodite with single row of prominent setae on posterior side of medial thickening and shorter row of similarly prominent setae on anterior side. Pseudoflagellum ca 1/2 width of telopodite at base, posterior margin a little expanded at 1/3-1/2 pseudoflagellum height, apex acuminate and directed posteriorly.
Distribution. Eucalypt forest on Forestier and Tasman Peninsulas (Fig. 7A) in Tasmania, from near sea level to at least 260 m.
Name. For the Tasman Peninsula, type locality of this species; adjective.
Other material. 92 males, 1 probable female and 1 possible juvenile from 8 unique localities; details in Suppl. material 1.
Diagnosis. Distinguished from all other Amastigogonus species by having a long, gradually tapering, narrowly ribbon-like pseudoflagellum.
Distribution. Eucalypt forest and cool temperate rainforest at scattered locations in northeast Tasmania (Fig. 7A), from ca 100 m elevation to at least 1000 m. Cooccurs with A. fossuliger.
Remarks. The types were in excellent condition when examined in 2016. Because it is not possible to decide which of the two dissected male syntypes (or both) was illustrated by Brölemann, I am unable to follow Recommendation 74B (Preference for illustrated specimen) of the International Code of Zoological Nomenclature in choosing a lectotype, and instead have selected the intact male syntype. The lectotype is the third of the three males listed by Brölemann (1913: 154): "length 44 m/m; diameter 2.80 m/m; 56 segments; three segments apodous; 99 pair of legs". I suspect that the type locality is the Launceston area, and the QVM male illustrated in Figs 3F, 4F and 5A is from Mowbray in Launceston. Diagnosis. Like A. elephas sp. n. in having a telopodite with a subquadrate extension of the posterobasal margin and a posteriorly curving pseudoflagellum; distinguished from A. elephas sp. n. in the pseudoflagellum lacking a small, tooth-like, distally directed extension on the tip.
Coxite process on anterior gonopod (Fig. 8D) with small portion of posterodistal margin extended as rounded tab, sharply folded over laterally. Telopodite with posterobasal surface produced posteriorly as subquadrate flange ( Fig. 8D; fl) and with single row of prominent setae on posterior side of medial thickening, on anterior side of thickening continued to telopodite apex as short row of more closely spaced setae (not shown in Fig. 8D). Pseudoflagellum arising at ca 2/3 telopodite height, ca 1/2 width of telopodite at base, curving posterodistally, the apex narrowing to truncate, posterobasally directed tip.
Distribution. Widespread in forested and some non-forested habitats in western and southern Tasmania and on the Central Plateau (Fig. 7A) from sea level to at least 1260 m; also found on Hunter Island in the Hunter Group in western Bass Strait. Overlaps (with some parapatry?) with A. hellyeri sp. n. in northwest Tasmania, and with A. fossuliger on the Central Plateau and possibly in far southern Tasmania (see distribution notes for A. fossuliger).
Remarks. Gervais (1847) described Iulus Verreauxii from material in the Muséum national d'Histoire naturelle in Paris. A presumed holotype was still in the Muséum more than 150 years later and was redescribed and illustrated by Mauriès, Golovatch and Hoffman (2001), who assigned the species to Amastigogonus. The type material had probably been collected on Mt Wellington by the naturalist Jules Pierre Verreaux ca 1843 during his residency in Tasmania (Maiden 1910: 153). Paratypes. 1 male, 1 female, details as for holotype, QVM 23:54176. Other material. 7 males, 5 females and 5 juveniles from 7 unique localities in Tasmania; details in Suppl. material 1.
Diagnosis. Most similar to A. gibsoni Edward & Harvey, 2010 from the Ravensthorpe Ranges in Western Australia; both species have a wedge-shaped sclerite "b" and a non-bifurcate sclerite "c". Differences between A. bonhami/A. gibsoni: rounded tab present under sclerite "a" near pseudoflagellum/no tab; anterior corner of distal margin of sclerite "b" higher than posterior corner/anterior corner lower than posterior corner; sclerite "c" taller than sclerite "b"/ sclerite "c" shorter than sclerite "b". Description. Atelomastix as a genus has been well characterised by Edward and Harvey (2010), who described or redescribed 27 species from Western Australia. A. bonhami sp. n. fits the genus description and only key details are noted here.
Male gonopod aperture with sides slightly raised (Fig. 9A). Anterior gonopods nearly touching along midline. Sclerite "a" (Fig. 10A) curving posteriorly with pseudoflagellum ( Fig. 10A; ps) arising at ca 3/4 gonopod height, extending posteriorly and slightly distally and gradually tapering to rounded apex; a thin, rounded tab ( Fig.  10A; t) arising just distal to pseudoflagellum origin along sclerite midline. Sclerite "b" arising medially at ca 1/3 gonopod height, ca 3x as wide distally as at origin, thickly lamellar with distal half slightly bent medially, the distal margin with rounded anterior corner, sloping posterobasally with small, rounded notch at posterior corner; a double row of small, short setae near distal margin. Sclerite "c" more or less cylindrical basally, the apex curving slightly anteriorly and spatulate, the concave surface facing anterolaterally; a few long setae on anterior surface of sclerite at level of sclerite "b" distal margin.
Posterolateral margin of preanal ring meets epiproct margin at obtuse angle, making anal valves appear more prominent in lateral view than in other Tasmanian Iulomorphidae (Fig. 9C).
Distribution. Known from wet forest, rainforest and scrub over ca 1500 km 2 in southwest Tasmania at elevations ca 300-1100 m (Fig. 7D).
Name. For Kevin Bonham, Tasmanian malacologist and diligent millipede hunter, who collected this species at two remote sites in 2016; noun in the genitive case.
Remarks. The posterior gonopod of A. bonhami sp. n. is similar to that of A. nigrescens as illustrated in figs 13, 14 and 118 of Edward and Harvey (2010), and leg 1 of A. bonhami sp. n. closely resembles leg 1 of A. solitaria as illustrated in fig. 2 of Jeekel (2009). Jeekel (2009 does not show the A. solitaria anterior gonopod in lateral view, so the shapes of the sclerites are unclear. From Jeekel's description of A. solitaria and his fig. 4, it appears that sclerite "c" is sharply bent with an acuminate apex, unlike the smoothly curving, apically rounded sclerite "c" of A. bonhami sp. n. and the following species, and is shorter than "b", rather than longer as in A. bonhami sp. n. and the following species. Other material. None. Diagnosis. Readily distinguished from the otherwise similar A. bonhami sp. n. by the pseudoflagellum curving distally; this difference can be seen in undissected males. Description. As for A. bonhami sp. n., but the two known males with 40-50 ocelli in 5-6 horizontal rows; holotype with (54+0) rings, 2.2 mm midbody diameter, paratype with (47+1) rings, 2.1 mm. Females (QVM 23:54484) more robust than males: (42+1) and (47+0) rings, both 2.5 mm in midbody diameter.
Distribution. Known from two localities ca 45 km apart at ca 900 m elevation, south and west of the known range of A. bonhami sp. n. in southwest Tasmania (Fig. 7D). A. smithi sp. n. is likely to be more widely distributed in this little-sampled wilderness area.
Name. For Steven J. Smith, first collector of this species and formerly a senior zoologist with the Tasmanian Parks and Wildlife Service; noun in the genitive case.
Equestrigonus gen. n. http://zoobank.org/0FB5A7A5-C4DE-4C93-A17A-8D857A7C9B4A Diagnosis. Like Amastigogonus and Victoriocambala Verhoeff, 1944 in having greatly reduced posterior gonopods with a single lateral process, and relatively simple, twobranched anterior gonopods with the prostatic groove entering a pseudoflagellum on the telopodite. Distinguished from the other two genera by the form of the anterior gonopods (Figs 11A, 13A): coxite process a bluntly pointed rod, longer than telopodite; telopodite slender with a distal, spreading crown of setae. Distinguished from all other Tasmanian Iulomorphidae by the posteroventral extension of the cardo ( Fig.  12B; ce) in males.
Type species. Equestrigonus tasmaniensis sp. n., by present designation. Name. From Latin equestris, genitive singular of equester, pertaining to horse-riding, plus -gonus, a suffix commonly used in millipede names, referring to the gonopods; masculine gender. The tips of the anterior gonopod of the type species (Fig. 11A) resemble the ends of prick and rowel spurs. Other material. 1013 males, 82 probable females and 12 possible juveniles from 68 unique localities in Tasmania; details in Suppl. material 1.
Description. Living animals (Fig. 12A) have dark grey rings with annular pale band at rear of each metazonite; head, collum and last 1-2 rings before telson tinged with light brown; legs pale. With long storage in alcohol, ring colour fades to dark blue-grey, annular band darkens to light grey; often with brownish tinge on anterior rings; head and legs pale golden yellow (Fig. 11B).
Legpair 1 (Fig. 12C, D) separate on coxosternite, each leg 1 composed of broad basal and leg-like distal portion. Basal portion here assumed to be prefemur; widest at base, tapering medially, extending anterolaterally at base as large lobe ( Fig. 12D; all) with a few distal setae; prefemur marked with several quasi-annular chitinous ridges and anteriorly bearing small field of coarse setae ( Fig. 12D; sf), with large subquadrate tab ( Fig. 12D; at) extending anteriorly. Distal portion with 3 well-demarcated podomeres, here assumed to be femur, postfemur and fused tibia+tarsus; femur widest, the tibia+tarsus narrowest and longest and with faint annular subdivision; all 3 podomeres sparsely and shortly setose; no claw.
Coxae not elongated on near-aperture legs. Rear portion of gonopod aperture flat, not raised behind gonopods.
Posterior gonopods (Fig. 13B) ca 1/2 length of anterior gonopods, tapering from base, apex truncate distolaterally with apical crown of long setae; lateral process arising at ca 1/2 gonopod height, terminating at same level as body of gonopod, tip slightly expanded and flattened with convex distal margin.
Mature females (specimens in QVM 23:54050 and 23:54467) a little larger than males with same ring number; cardo not extended ventrally as in male.
Distribution. Wet eucalypt forest and cool temperate rainforest in northern Tasmania (Fig. 7D), from 50 m to at least 900 m elevation; not yet collected south of 41°30'S latitude. Wanders on the forest floor and climbs tree trunks at night; shelters during the day in and under rotting logs and in leaf litter.
Name. For the occurrence of this species in Tasmania; adjective.
Remarks. The distinctive tips of the anterior gonopods invariably protrude from the gonopod aperture (Fig. 11A), allowing males of E. tasmaniensis gen. n., sp. n. to be recognised without dissection. Western Tasmanian males are generally a little larger in diameter than eastern males.

Discussion
I am not certain that Amastigogonus and Equestrigonus gen. n. are endemic to Tasmania, because the iulomorphid fauna of mainland Australia is still very poorly known. The few well-described iulomorphids from the eastern Australian mainland, closest to Tasmania, were named from a small number of specimens mostly held in non-Australian collections: Apocoptogonus Jeekel, 2006 (two species from one locality each in New South Wales), Atelomastix (one species from one locality, Victoria), Dimerogonus Attems, 1903 (one species from one locality, New South Wales), Merioproscelum Verhoeff, 1924 (one species from one locality, Queensland), Proscelomerion Verhoeff, 1924 (one species from one locality, Queensland), Thaumaceratopus Verhoeff, 1924 (two species from one locality, Queensland) and Victoriocambala (one species from one locality, one species from six localities, Victoria) (Mesibov 2006(Mesibov -2017. Like the dalodesmid Polydesmida genus Tasmaniosoma Verhoeff, 1936(Mesibov 2010, 2015, Amastigogonus in Tasmania has its highest species diversity on the east coast of the main island, with several small-range endemics there and some mosaic parapatry. Parts of the east coast, and especially the surrounds of the city of Hobart, have unfortunately been degraded by almost 200 years of clearing, grazing and frequent burning. Native millipede populations have been greatly reduced or eliminated as a result, and in some places have been completely replaced by the introduced Ommatoiulus moreleti (Lucas, 1860) and other European julids. The iulomorphid most at risk may be the Hobart-area endemic A. hardyi, which has not yet been found in the city's larger conservation reserves.
The recognition of two Atelomastix species from a high-rainfall district in Tasmania is an interesting result of the present study. Jeekel (2009: 34) wrote that the discovery of A. solitaria was "a remarkable and unexpected extension of the known range of the genus Atelomastix from the south-western area of Western Australia to the western edge of Victoria" and considered it possible that the label locality was accidentally in error. It now seems possible that Atelomastix species could also occur in high-rainfall parts of eastern Victoria, and perhaps southern New South Wales.
Using a draft version of this paper, Henrik Enghoff (in litt., 26 July 2016) has identified Amastigogonus tasmanianus and A. verreauxii as millipede species that are parasitised by the fungus Rickia candelabriformis Santamaria et al., 2016 and that were referred to as undetermined Iulomorphidae in Santamaria et al. (2016). The relevant records are included in Suppl. material 1.