Review of Dragon Millipedes (Diplopoda, Polydesmida, Paradoxosomatidae) in the Fauna of Vietnam, with Descriptions of Three New Species Author Nguyen, Anh D. Author Nguyen, Manh-Ha Author Nguyen, Thu-Anh T. Author Phung, Hong-Luong T. text Zoological Studies 2019 2019-07-12 58 14 1 31 journal article 56108 10.6620/ZS.2019.58-14 de0647eb-9b73-4bac-9ff7-f7bff7518dc0 PMC6759935 31966315 8065869 Hylomus songoku sp. nov. ( Figs. 1 , 16−20 ) urn:lsid:zoobank.org:act: 030505EE-DF75-4832-ABF1- CC70AB989A03 Material examined : Holotype : 1 male (IEBR- Myr 164H) Phu Tho Province , Xuan Son National Park , Lap cave , 11 December 2010 , coll. Phung T . H. Luong . Paratypes : 1 male , 3 females (IEBR-Myr 164P) same data as holotype . Etymology : The name refers to “ songoku ”, a main character of the Japanese manga “Dragon balls” by Toriyama Akira ( Japan ). Diagnosis : The species differs from its congeners in suberect gonopod; solenophore with rounded lobuliform lamina medialis, and well developed lamina lateralis with densely setose area; tip of solenophore tuberculiform. Description : Body length ca. 17.9−25.2 mm (male), 23.9−26.8 mm (female); width of midbody pro- and metazonae 1.1−1.2 mm (male), 2.1−2.3 mm (female) and 1.3−1.4 mm (male), 2.4−2.5 mm (female), respectively. Holotype length 25.2 mm , width of midbody pro- and metazonae 1.2 mm and 1.4 mm , respectively. Colouration ( Figs. 16−18 ): body generally light yellow. Pleura yellowish brown; head yellowish and somewhat darker on the region between antenna sockets. Head ( Fig. 16A ) slightly broader than collum. Clypeolabral region densely setose. Epicranial suture distinct, linear. Antennae ( Fig. 16A ) slender, thin and extremely long, reaching segment 7 or 8 if stretched posteriorly; antennomere 3> 4> 5> 2> 6> 7> 1 in length; antennomere 7 black. Collum ( Figs. 16 A−B) somewhat narrower than segment 2 in width; surface shining, densely microgranulated and wrinkled, with two rows of setiferous spines: one of 10−12 smaller spines close to anterior margin and, one of 4 + 4 larger spines near posterior margin; the posterior spines gradually smaller medially. Paraterga well developed, highly elevated, antler-shaped with three branches. Width of body segment 4 <3 <2 = 5−16, thereafter gradually tapering towards telson. Prozonae shining and shagreened. Metazonae with dense microgranulation. Transverse sulcus starting on metatergum 5, but vague, incomplete, thin and line-shaped. Metaterga densely granulated with two rows of setiferous spines; the anterior spines variable, tiny whereas posterior spines longer and larger, 3 + 3 on metaterga 2−3, 4 + 4 on metaterga 4−5, 5(6) + 5(6) on subsequent metaterga ( Figs. 16 C−D, 17A, C); metatergum 19 with numerous small setiferous spines, but not arranged in row. Pleurosternal carinae absent. Axial line present, thin and line-shaped. Waist between pro- and metazonae broad, neither striolate nor beaded. Paraterga ( Figs. 16 , 17 A−C) well developed, antler-shaped, with 5−6 branches (one main branch, 2−3 anterior ones and 1−2 posterior ones), highly elevated from metatergal surface, sometimes with several very tiny setiferous spines around base. Ozopore on segments 5, 7, 9−10, 12−13, and 15−19, lying under the base of the second anterior branch. Epiproct ( Figs. 17D , 18 A−B) strongly modified with two large lateral setiferous tubercles. Tip normal with four spinnerets. Hypoproct ( Fig. 18B ) trapeziform with two well separated, distolateral setiferous knobs. Sterna ( Fig. 17 D ) modestly setose; cross impression vague, without modifications except two separated, setiferous tubeliform processes between coxae 4 ( Fig. 18C ). Legs slender and extremely long, about 3−3.5 times as long as midbody height. Prefemora not swollen. Femora without modifications except femora 6 & 7 with a big ventral tubercle at 2/3 its length ( Fig. 18D ). Tarsal brushes absent. Gonopod ( Figs. 19−20 ) simple. Coxite (co) about 1/3 as long as telopodite. Prefemorite (prf) about half as long as acropodite, densely setose, demarcated laterally from femorite by a transverse sulcus. Femorite (fe) longer than postfemoral region, slightly enlarged distally, and somewhat curved ventrad. Postfemoral region suberect, consisting of solenophore (sph) and solenomere (sl). The former simple with a rounded lobuform (rl) lamina medialis and well developed lamina lateralis with a densely setose region (ds). Solenomere flagelliform, partly sheathed by solenophore. Seminal groove running entirely mesally, directed distodorsad before entering the solenophore. Tip (tp) of solenophore tuberculiform. Remarks : The species was found in the Lap cave, and it is the first troglobitic species of the genus Hylomus recorded in Vietnam .