Decapauropus undulatulus, Scheller, Ulf, 2011

Scheller, Ulf, 2011, New records of Pauropoda (Myriapoda) from north-western Thailand, International Journal of Myriapodology 4, pp. 51-77 : 62-64

Decapauropus undulatulus sp. n. Figs 46-52

Material.

Holotype ad. 9(♀), Thailand, Chiang Mai province, Doi Inthanon, Mae Chaem road, secondary dry forest, litter, alt. 1150 m, 1991.vi.30, loc. CM-080.

Etymology.

From the Latin undulatus, wavy (referring to the distal margin of the 4th antennal segment).

Diagnosis.

Many species in the genus have linguiform anal plates with two appendages but none of them has the appendages placed in the middle of the tergal side as in Decapauropus undulatus sp. n. Moreover is this species well defined by the peculiar undulated distal margin of the 4th antennal segment and the wide collum appendages which are directed inward/anteriorly. At present its relationships are not possible to trace.

Description.

Length. 0.52 mm. Head. Not available for study.

Antennae (Fig. 46). Distal margin of segment 4 distinctly wavy, four setae; their relative lengths: p=10, p’ =7, p’’ =3, r=4. Setae annulate, p and p’ grow thicker outward, p’’ and r cylindrical. Tergal seta p 1.5 times as long as the length of tergal branch t. The latter fusiform, 1.3 times as long as its greatest diameter and 0.8 of the length of sternal branchs,that branch subcylindrical, 1.3 times as long as its greatest diameter; anterior truncation weak. Seta q cylindrical striate, inserted very near distal margin, as long as the length of s. Relative lengths of flagella (basal segments included) and basal segments: F1=100, bs1=7; F2=44, bs2=4; F3=88, bs3=7. F1 5.5 times as long as t, F2 and F3 4.6 and 5.1 times as long as s respectively. Distal calyces small, distal part of flagella axes inconsiderably widened below calyces. Globulus g proportionally large, pyriform, 1.4 times as long as wide, ≈9 bracts, capsule with flattened bottom; width of g 0.6 of the length of the greatest diameter of t. Antennae glabrous.

Trunk (Figs 47, 48). Setae on collum segment simple cylindrical striate, only one pair could be proved (Fig. 47); sternite process small, indistinct; appendages large short cylindrical directed inward and anteriorly, caps low. Process and appendages glabrous.

Setae on tergites only partly available for study, those proved thin cylindrical. Tergite VI with 4+2 setae, submedian posterior ones (Fig. 48) 0.9 of interdistance.

Bothriotricha (Fig. 49). Relative lengths: T1=100, T2=98, T3=79, T4=104, T5=?; axes simple straight thin in T1, T2, T4 and T5, pubescence there faint on proximal halves, on distal halves of T1, T2 and T4 distinct, partly erect, probably branched most distally; axes of T3 (Fig. 49) somewhat thickened in proximal half, pubescence there oblique, on distal half as on other bothriotricha.

Legs (Figs 50, 51). Setae on coxa and trochanter (Fig. 50) of leg 9 furcate, branches cylindrical blunt striate, secondary branch shorter and thinner than primary branch. These setae more anteriorly with rudimentary secondary branches. Tarsus of leg 9 (Fig. 51) tapering, 3.6 times as long as its greatest diameter; proximal seta very thin tapering pointed, distal seta cylindrical blunt striate, proximal seta 0.3 of the length of tarsus and 1.7 times as long as the length of distal seta. Cuticle of tarsus glabrous.

Pygidium (Fig. 52). Tergum. Posterior margin with three posterior lobes, one each posterior of insertion point of st and one broader in between. Relative lengths of setae, a1 not proved, a2=10, a3=23, st=15; a2 cylindrical blunt glabrous, a3 tapering pointed, striate distally, both setae curved inward and diverging; st somewhat clavate striate, directed posteriorly and curved inward. Distance st-st 2.2 times as long as st.

Sternum. Posterior margin with low lobe inside each seta b1, straight in between. Relative lengths of setae (pygidial a2=10): b1=37, b2=21, setae thin tapering, b1 striate, as long as interdistance, b2 almost as long as distance b1-b2.

Anal plate directed posteriorly, 1.2 times as long as wide, linguiform with convex lateral and posterior margins, thickened in most posterior part, two short appendages protruding from the middle of tergal side.