Diagnosis.

Gonofemorite strongly curved, distal part somewhat swollen and membraneous. Postfemoral region demarcated from femorite by obvious cingulum, and bent continuously forming almost a complete circle with femorite. Postfemoral regions consisting of a thick, strong and free solenomere, and an extremely short solenophore (= tibiotarsus).

Type species.

Riukiupeltis jamashinai Verhoeff, 1939

Remarks.

This genus is relatively close to the genus Chamberlinius Wang, 1956, however, it definitely differs in gonopod conformation: femorite without lamina; solenophore very short, thick, and without any basal processes.

Material studied.

Holotype male, in fragments – only 11 segments in 5 pieces – with segments around gonopods missing, Reg.-Nr. ZSMA20052252, and two slides with gonopods, Reg.-Nr. ZSMA20035204, and legpairs 1–7, Reg.-Nr. ZSMA20035205 (all BSCZ).

New records: 2 males, 2 females, Japan, Ryukyu Archipelago, Miyako-jima Island, Rinko-abu (cave), 21 August 1979; 8 males, 2 females, Japan, Ryukyu Archipelago, Miyako-jima Island, Fukumine-no-kara (cave), 25 August 1979; 1 male, 1 female, 1 juv., 1 fragment, Japan, Ryukyu Archipelago, Miyako-jima Island, Nishibe zuzaga (cave), 26 August 1979, all leg. M. Shimojana (in the collection of M. Shimojana, Okinawa).

Distribution.

Japan, Ryukyu Archipelago, Miyako-jima island.

Remarks.

Although after the description of Riukiupeltis jamashinai in 1939, Jeekel (1968) and Hoffman (1973) commented that gonopod tibiotarsus is missing in this species, Verhoeff’s line drawing clearly shows it as depicted from the slide preparation (Fig. 1). Re-examining the type specimen and the slide of the gonopod, as well as studying newly identified specimens found in Shimojana’s collection, we are able to confirm that a gonopod tibiotarsus (=solenophore, sph in Fig. 2) is present, although it is small and closely attached to solenomere (sl in Fig. 2).

Material studied.

Holotype male, NSMT-My 358, “Japan, Okinawa Pref., Is. Ishigaki-jima, Ibaruma, Sabichi-go Cave, 31 July 1973, coll. by S. Uéno” (NMNS).

New records: 2 males, 1 female, Japan, Ryukyu Archipelago, Yaeyama Island Group, Ishigaki-jima Island, Banna-dake, secondary forest, N24.3859°, E124.1651°, 30 August 2009, leg. Z. Korsós & Y. Nakamura (RUMF); 1 male, 2 females, Japan, Southern Ryukyus, Yaeyama Group, Iriomote-jima Island, Funaura, around university research station, N24.3929°, E123.7913°, secondary forest, 18 January 2011, leg. Z. Korsós (RUMF); 1 male, 1 female, Japan, Southern Ryukyus, Yaeyama Group, Iriomote-jima Island, Mihara, along Aira river, primary forest, N24.3400°, E123.9137°, in decaying log, 12 m a.s.l., 19 January 2011, leg. Z. Korsós (HNHM).

Distribution

. Japan, Ryukyu Archipelago, Yaeyama Group, Ishigaki-jima and Iriomote-jima islands.

Remarks.

Murakami (1975) when describing the species commented that the terminal portion of the gonopod is more complicated than that of Riukiupeltis jamashinai Verhoeff, 1939. He also agreed with Verhoeff, 1939 in its configuration, and placed his species in Riukiupeltis. However, the species uenoi, in fact, differs largely from the type species Riukiupeltis jamashinai in gonopod conformation.

After studying the type and freshly collected specimens, it became clear that the species uenoi is strongly different from Riukiupeltis jamashinai in its gonofemorite having a long lamina l, and a longer solenophore with basal processes pp and lp (Fig 3). We found that this species is more similar to Chamberlinius hualienensis Wang, 1956. Both Chamberlinius hualienensis and Chamberlinius uenoi comb. n. have well-developed paraterga (Figs 7A–B), large, slender and strongly concave gonofemorite, with a lamina at the mesal side (l in Fig. 3). Postfemoral region is demarcated from femorite by obvious cingulum (c in Fig. 3), and includes a long and large solenomere (sl) reaching femur, and a shorter solenophore (sph) with a basal lobe. However, the two species differ from each other in the length of the postfemoral processes, by the shape of the small basal processes on the solenophore, and by live colouration. The dark brown, transversal metatergal bands in Chamberlinius uenoi comb. n. are not divided by a median light brown longitudinal line (Figs 7C, 8C) as in Chamberlinius hualienensis (Figs 7B, 8B). Moreover, Chamberlinius uenoi comb. n. is strictly confined to undisturbed, natural evergreen broadleaf forests, and can only be found deep in decaying dead wood, whereas Chamberlinius hualienensis has a strong tendency for being synanthropic, and dispersed in large numbers onto many islands (especially in the southern part of Japan) by human activities.

Type species.

Haplogonosoma falcatum Attems, 1953, by present designation

Diagnosis.

This genus, Simplogonomorpha gen. n. can be distinguished from other genera within the tribe Chamberlinini Wang, 1956 (as defined by Chen et al. 2011) by the following characters: paraterga modestly developed, gonopod very simple, gonotelopodite tapering and distally curved down as much as forming U-shape or an almost complete circle. Solenomere very simple, thick, but slender, and strongly curved down. Solenophore (= gonopod tibiotarsus) absent.

Etymology.

A feminine noun to emphasize the simple gonopod conformation.

Remarks.

Jeekel (1968) in his classification of the family Paradoxosomatidae stated that “It appears that in Riukiupeltis the gonopod tiobiotarsus is also completely lost, although Verhoeff was of a different opinion when he described jamashinai”. He believed that the gonopod tibiotarsus (= solenophore) was lost in Riukiupeltis, so he transferred Attems’s species Haplogonosoma falcatum to this genus.

In fact, the solenophore of Riukiupeltis jamashinai still exists, although short, and somewhat hidden next to the solenomere, whereas solenophore of Simplogonomorpha gen. n. is totally missing. A comparison of genera in the tribe Chamberlinini is provided in Table 1.

Material studied.

3 males, 2 females, (IEBR-166), Vietnam, Lam Dong prov., Bi Doup-Nui Ba National Park, corn field, 1400m a.s.l., pitfall traps, 2–9 April 2008, leg. Anh. D. Nguyen; 1 male, 1 female, 1 juvenile, (IEBR-167), same locality, grasslands, 1400m a.s.l., pitfall traps, 2–9 April 2008, leg. Anh. D. Nguyen; 1 female, (IEBR-168), same locality, bushes near stream, 1400m a.s.l., pitfall traps, 25 April 2008, leg. Anh. D. Nguyen; 4 males, 2 females, (IEBR-169), same locality, evergreen forest, 1800m a.s.l., 25 March–23 April 2008, leg. Anh. D. Nguyen;1 male (IEBR-125), Vietnam, Khanh Hoa Prov., Hon Ba Mts., 1300–1500m a.s.l., primary forest, 15–24 April 2006, leg. Anh. D. Nguyen; 1 male, 1 female, (HNHM), same data as sample IEBR-125.

Description.

Head: yellowish-brown to blackish brown, a slightly paler toward labrum. Epicranial suture distinct, obviously deep.

Antennae: short and stout, yellowish-brown to blackish brown. Length of antennomere 2 subequal to that of antennomere 3, 4 or 5. Antennomere 6 shorter and claviform.

Body: yellowish-brown to blackish brown on terga, paler on paraterga and pleura. Body parallel-sided on somites 5–17, thereafter gradually tapering.

Surface of metaterga general fine in posterior part, but with small oblique or longitudinal rugulose in anteriormost part. Stricture dividing pro- and metazona deep, obvious and beaded. Prozona surface shagreened with fine microgranulation.

Transverse sulcus on metaterga starting from somite 5 and more evident on subsequent somites. Metaterga with a row of 2+2 setae in pre-sulcus part. Axial line vague.

Paraterga not well-developed, small, look like small keels in poreless segments, but more developed in pore-bearing somites. Ozopore located on lateral side, near tip of angular paraterga of segments 5, 7, 9–10, 12–13 and 15–19.

Pleura shagreened with fine microgranulation. Pleurosternal carinae rather well-developed in anteriormost segments, gradually decreasing posteriorly.

Epiproct truncated and curved down ventrad, with 4 strong setae on tip. Anal valves sub-semicircular with 1+1 long setae, and a deep emargination inbetween. Hypoproct trapeziform, with 1+1 setae.

Legs: yellow to yellowish brown, short and stout. Tarsal brushes present until legpair 10, sparsely until legpair 16, and completely missing thereafter.

Sterna: normal, sparsely setose, with two large tubercles between coxae 4.

Male gonopod: very simple, hook-like in dorsal view. Coxa subcylindrical, distoventral part sparsely setose. Prefemoral part usually densely setose, with evident demarcation from both femorite and coxa. Femorite slender, much longer than coxite and a little curved down distally, separated from postfemoral part by an evident, subtransverse sulcus laterally and mesally. Solenomere simple, strongly curved down, slender, and tapering at tip. Tibiotarsus totally absent.

Prostatic groove runs mesally along femorite, distolaterad, and turns to lateral side, then running mesally, and ending at tip of solenomere.

Distribution.

Vietnam, Lam Dong province, Bi Doup-Nui Ba National Park; Khanh Hoa province, Hon Ba Mountain; Laos PDR, Xieng Khoang

Remarks.

New material does not much differ from Attems’s description. Only minor difference is the presence of two separate cones between coxae 4 instead of only one small conal process in Attems’s description. Recently, Chen et al. (2011) also published an illustration of gonopods of Haplogonosoma falcatum collected from the same locality, BiDoup National Park, Vietnam. Our material here fits well with their unevaluated illustration.

Key to representatives to all three genera (based on male characters)

In the key above, Riukiupeltis and Simplogonomorpha are represented by only one species each (jamashinai and falcata, respectively). Chamberlinius, on the other hand, includes at present five species: Chamberlinius hualienensis, Chamberlinius piceofasciatus, Chamberlinius pessior, Chamberlinius sublaevus (all keyed already by Chen et al. 2011), and Chamberlinius uenoi, as added here.