Sundanina medialis, Nguyen, Anh D., 2010

Nguyen, Anh D., 2010, The millipede tribe Sundaninini in Vietnam (Diplopoda: Polydesmida: Paradoxosomatidae), Zootaxa 2479, pp. 59-68 : 62-64

Sundanina medialis sp.nov.

Figs. 12–19 .

Material studied: HOLOTYPE ♂, ( IEBR) Vietnam, Thanh Hoa Prov., Thach Thanh District, Thach Lam commune, 20 0 21’N, 105 0 31’E, agricultural land, 25/4/2007, leg. Nguyen Duc Hiep. PARATYPE: 1 ♂, ( IEBR) Vietnam, Ninh Binh Prov., Cuc Phuong National Park, Dang Station, 20 0 18’N – 105 0 40’E, evergreen forest, 21/7/2006, leg. Luu Van Hien.

Etymology: “ medialis ”, an adjective to emphasize the lamina medialis of the solenophore supplied with a long, spiniform process.

Diagnosis: This species differs from the other Sundanina species in the gonopod postfemoral region supplied with a long, spiniform process at the base of the solenophore. The lamina medialis is very well– developed, with a long, suberect spiniform process. The tip is distinctly bifid.

Description: A rather large–sized paradoxosomatid ca. 32–36 mm long, width of midbody pro– and metazona 2.3– 2.5 and 3.4–4.0 mm, respectively. Holotype 36 mm long, 2.5 and 4.0 mm wide on pro– and metazona, respectively.

Coloration generally castaneous brown, except for transverse metatergal sulci and stricture dividing pro– and metazona paler. Paraterga yellowish, antennae paler than a yellowish brown body. Legs and sterna yellowish while pleura castaneous brown. Paratype somewhat darker.

Head: Epicranial suture very distinct, deep. Antenna: relatively long, slightly clavate, reaching the middle of segment 4.

Collum: transverse sulcus and axial line distinct, but former extending only to ½ of collum in width; with 3+3 small setiferous knobs near front margin.

Body: width of head <segment 5=2> 4> 3 = collum, parallel–sided on segments 5–17, thereafter gradually tapering toward telson. Surface of metaterga shining, slightly rugulose. Metaterga with traces of 2+2 setae and 4+4 small knobs near front and rear tergal margin, respectively ( Fig. 12 ). Transverse sulcus on metaterga well–developed already from segment 2 on, very distinct, deep and reaching the base of paraterga. Prozona and pleura smooth. Stricture dividing pro– and metazona deep and obvious, longitudinally striolate dorsally. Pleurosternal carinae as small flaps, present until segment 7, then tuberculiform on segments 8–11 and wanting on subsequent segments. Paraterga well–developed, set low (at about ½ of metazonital height). Paraterga with two small teeth/incisions located at 1/3 and 2/3 of paratergal length on poreless segments, and only a small tubercle on lateral side of paraterga on pore–bearing segments. Paratergal callus small, but evident in dorsal view. Caudal corner of paraterga acute, not surpassing rear tergal contour. Ozopore lying inside an ovoid hollow on lateral side of paraterga, barely visible in dorsal view.

Epiproct small, concave and slightly curved down ventrally, tip with several setae, also with two long tubercles distolaterally ( Fig. 13 ). Hypoproct subtraperziform.

Sterna sparsely setose, without any modifications, cross–impressions moderate; a bifid lamina between coxae 4 ( Fig. 14 ). Legs very long and slender, ca 1.5 times longer than body height, with neither any femoral modification nor tarsal brushes.

Gonopods ( Figs 15–19 ) relatively simple. Coxite long, subcylindrical, distoventral part sparsely setose. Prefemur short, as usual densely setose. Femorite suberect, slender and rather long, somewhat longer than coxa, postfemoral region demarcated by a distinct and oblique sulcus laterally. Postfemoral region well– developed, suberect, as long as femorite, with a long, spiniform outgrowth (ot) at base of solenophore (sph). The latter consisting both of a simple lamina lateralis (ll) and, especially, a well–developed lamina medialis (lm) with a long, well–developed, suberect, spiniform process (sp). Solenophore tip distinctly bifid. Seminal groove running mesally on femorite and turning distoventrad before entering a free, flagelliform solenomere (sl).

Remarks: This new species seems to belong to the group of Sundanina species showing a single femoral process (e.g. S. infausta (Silvestri, 1895) , S. simillima (Silvestri, 1895) , S. aphanes (Attems, 1898)) ( Jeekel 1979) , yet it can be distinguished by the femoral process arising from the base of the solenophore, whereas the lamina medialis is supplied with a long, spiniform process in the middle.

Figures

FIGURES 12 – 16. Sundanina medialis sp. nov., ♂ holotype: segment 10, dorsal view (12); right half of epiproct, dorsal view (13), sternal lobe between coxae 4, posteroventral view (14); left gonopod, mesal view (15), lateral view (16). Scale bar = 1 mm

FIGURES 17 – 19, 25. Sundanina medialis sp. nov., ♂ holotype: left gonopod, lateral view (17), postfemoral region, lateral view (18), tip of gonopod, dorsal view (19). Sundanina cochinchina sp. nov., ♂ holotype: left gonopod, mesal view (25).