Orthorhachis tallagandensis, Mesibov, 2008

Mesibov, Robert, 2008, The millipede genera Gephyrodesmus Jeekel, 1983 and Orthorhachis Jeekel, 1985 in southeastern Australia, a new Lissodesmus Chamberlin, 1920 from Victoria, and observations on male leg setae, spinnerets and metatergite sculpture (Diplopoda: Polydesmida: Dalodesmidae), Zootaxa 1790, pp. 1-52 : 42-43

Orthorhachis tallagandensis n. sp.

Fig. 27; map Fig. 31

Holotype: Male. Approx. 750 m NE of apex of Mt Bollard , Tallaganda State Forest, NSW, 35º39'14"S 149º28'44"E, 1110 m (GE), 15 March 1999, J. Tarnawski & S. Lassau, CBCR3-033 L, leaf litter. In AM, KS93483 .

Other material examined: None available.

Diagnosis: Gonopod telopodite with well and deeply separated branches; medial process terminating in two lobes separated by a wide notch. Posterior sternites with median tab-like structure along posterior edge.

Description: As for the genus. Male approximate measurements: length 14 mm, midbody prozonite diameter 1.3 mm, midbody width across paranota 1.8 mm. In alcohol, body colour near-uniform medium brown. Antennal sockets separated by 2X a socket diameter. Antennae slender, relative lengths of antennomeres 3>(2,6)>(4,5). Collum D-shaped, narrower than head and tergite 2. Metatergite sculpture indistinct, Pattern A. Paranota with anterior margin slightly convex, lateral margin more or less parallel to long axis of body. Legs slender, leg 6 tarsus 1.9X as long as femur. Brush setae with forked tips. Sternites of posterior rings (10–16?) with a small, median, rounded, two-lobed tab on posterior edge, less evident on anterior rings in the tab-bearing set.

Gonopod aperture ovoid, slightly wider than long, one-third the width of the ring 7 prozonite, rim raised posterolaterally. Telopodite ( Fig. 27) short, more or less cylindrical, constricting above broad base and tapering gradually in anterior or posterior view; long setae on posterolateral surface to between one-third and onehalf telopodite height; branching beginning just above one-half telopodite height. Solenomere cylindrical, directed posterodistally, slightly tapering, bending laterally at about three-quarters solenomere height, then curving distally. Medial process well-separated from solenomere, slightly flattened mediolaterally, curving slightly posteriorly, widening near apex and terminating at about three-quarters solenomere height in two lobes separated by a wide notch: anterior lobe distally directed and bluntly rounded, posterior lobe directed posteriorly and slightly distally, with a small, triangular projection on distal surface.

Female not yet known.

Distribution: Known only from at leaf litter at one site in moist montane eucalypt forest in New South Wales ( Fig. 31).

Etymology: For the type locality, Tallaganda State Forest.