Samarangopus choanephorus, Scheller, Ulf, 2011

Scheller, Ulf, 2011, New records of Pauropoda (Myriapoda) from north-western Thailand, International Journal of Myriapodology 4, pp. 51-77 : 69-71

Samarangopus choanephorus sp. n. Figs 72-83

Material.

Holotype ad. 9(♂), Thailand, Chiang Mai province, Doi Inthanon, below the top, primary rain forest, soil, alt. 2400 m, 1991.vii.4, loc. CM-195. - 1 specimen.

Etymology.

From the Greek choane, funnel, and phero, bear, carry (referring to the funnel-shaped organs on the tergites).

Diagnosis.

Samarangopus choanephorus sp. n. may be grouped together with Samarangopus umbonifer Scheller from Thailand ( Scheller 1995) and Samarangopus condylus Scheller from the Philippines ( Scheller 2009), for certain more to the former than to the latter. Good distinguishing characters in relation to Samarangopus umbonifer are the shape of the antennal globulus g, stalk much longer than globulus in Borneopauropus choanephorus , shorter in Borneopauropus umbonifer , the large funnel-shaped organs of the tergites, with central rod, not without, the protuberances of the posterior margin of the tergite VI, with evenly convex lateral margins, not with a small knob on each side, the shape of the setae on coxa and trochanter of leg 9, simple, not furcate, and the length of the pygidial setae b3, almost as long as the b2, not distinctly shorter.

Description.

Length. 0.74 mm. Antennae (Fig. 72). Chaetotaxy of segments 1-4: 2/2/2/2; no g´. Setae thin striate, on segment 4 only two proved, their relative lengths p=10, p´or p´´ =6. Tergal branch t almost cylindrical, 3.1 times as wide as greatest diameter and as long as sternal branch s. That branch twice longer than greatest diameter, anterodistal corner distinctly truncate. Seta q as setae of 4th segment, 0.5 of the length of s. Relative lengths of flagella (base segments included) and base segments: F1=100, bs1=18, F2=?, bs2~10, F3=85, bs3=17. F1 5.6 times as long as t, F3 3.3 times as long as s. Calyces conical; flagella axes inconsiderably widened below calyx. Globulus g 1.6 times as long as greatest width; 10 thin bracts, capsule spherical, diameter of g 0.8 of the greatest diameter of t. Antenna glabrous.

Trunk (Figs 73-77). Setae of collum segment (Fig. 73) similar thin furcate, main branch pointed striate, secondary branch rudimentary pointed; sublateral setae 1.3 times as long as submedian setae. Sternite process broad triangular pointed anteriorly. Appendages wide cylindrical, caps flat. All parts of collum segment glabrous.

Tergites with four main types of protuberances (Figs 74-77): 1. stalked campanulate marginal protuberances (Figs 74-77), short on anterior margin of tergite I, larger on lateral margins of tergites; 2. fungiform organs (Figs 74-77) with hat in the shape of an upside down transparent funnel with a central rod, foot subcylindrical, these distributed over whole the surface of tergites; 3. small subcylindrical organs with upside down funnel at top (Fig. 77); 4. many small conical structures in between the different protuberances. Number of marginal protuberances: (holotype only): I - 36, II, 1 small - T1 - 11; III, 8 - T2 - 8; IV, 8 - T3 - 6; V, 9 - T4 - 4, VI, 7 - T5 - 1.

Bothriotricha. All but T3 with very thin axes, curved distally. T3 (Fig. 78) with thicker axes distally forming a subcylindrical, almost glabrous, swelling, length ¼ of the length of bothriotrix. Relative lengths of bothriotricha (holotype only): T1=100, T2=95, T3=42, T4≈90, T5=89.

Genital papillae (Fig. 79). Conical, glabrous, 2.2 times as long as greatest diameter, setae long, 0.8 of the length of papillae, inserted below the middle of papillae.

Legs (Figs 80, 81).All legs 5-segmented. Seta on coxa and trochanter (Fig. 80) of legs 1-9thin simple striate. Tarsi tapering, those of leg 9 (Fig. 81) 3.7 times as long as its greatest diameter; two tergal setae, both pointed glabrous; length of proximal one 0.4 of the length of tarsus and 3 times longer than distal seta. Cuticle of tarsus glabrous. No proximal seta on tarsi of leg 1. All legs with large main claw and small setose anterior secondary claw; in leg 9 the former reaching 0.5 of the length of tarsus. Appendage on femur of leg 1 not studied.

Pygidium (Figs 82, 83). Tergum. Posterior margin undulate with larger pentagonal lobe between st. Setae a1 cylindrical, curved inward, converging, a2 short clavate straight converging, faintly pubescent distally, a3 long thin tapering pointed diverging, st straight lanceolate, faintly pubescent. Relative lengths of setae: a1=10, a2=6(-7), a3=(20-)21, st=(15-)16. Distance a1-a1 1.3 times as long as a1, distance a1-a2 as long as distance a2 -a3; distance st-st almost as long as st and 1.1 times as long as distance a1-a1. Cuticle glabrous.

Sternum (Fig 83). Posterior margin rounded. Setae long tapering pointed, b2 straight diverging, b3 somewhat curved inward. Relative lengths of setae (pygidial a1=10): b1=(45-)47, b2=(26-)29, b3=24(-25). b1 1.1 times as long as interdistance, b2 1.1 times as long as distance b1-b2, b3 0.6 of interdistance.

Anal plate (Fig. 82) 1.4 times as long as broad, lateral margins convex, distal part of plate cleft by a V-shaped incision into two somewhat tapering cylindrical branches; four appendages: each branch provided with one outer and one inner tooth and in between a straight bladder-shaped appendage, that broadest in distal half, length of appendage 0.4 of the length of plate; two short thin cylindrical appendages protruding outward-backward from lateral margins. Plate glabrous, appendages with faint pubescence.