Orthorhachis paradoxalis Jeekel, 2006

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 : 39-40

Orthorhachis paradoxalis Jeekel, 2006

Figs. 4A, 4B, 25; map Fig. 31

Orthorhachis paradoxalis Jeekel, 2006:74 , Figs. 1–3.

Holotype: Male. Paradox Cave J48, Jenolan, NSW, 2 January 1973, E. Hamilton-Smith, field code BS2183. Not examined.

Paratypes: None.

Other material: In AM: 1 male, 2 stadium 7 females, Grill Cave , Bungonia, NSW, 20 April 1971, G. Wellings, KS94904 ; 5 males, 3 females, Budthingeroo Creek , Boyd Plateau via Jenolan Caves, NSW, near pluviometer, 3500 ft, 9 September 1972, G.S. Hunt, under logs, KS94893 ; 3 males, 1 female, Jenolan Caves area , NSW, southern limestone area, 6 July 1989, G.S. Hunt, KS21677 ; 1 male, 5 females, same details but 14 August 1989, KS22527 .

Diagnosis: Gonopod telopodite with tight medial loop in solenomere. Posterior sternites with median tablike structure along posterior edge.

Description: As for the genus; see Jeekel (2006) for a detailed description of the O. paradoxalis holotype. Male/female approximate measurements: length 18/ 19 mm, midbody prozonite diameter 1.4/ 1.5 mm, mid- body width across paranota 2.1/ 2.2 mm. Body slightly discoloured, light brown. Antennal sockets separated by 2X a socket diameter. Antennae slender, relative lengths of antennomeres (2,3)>6>(4,5). Collum D-shaped, as wide as head and and tergite 2. Metatergite sculpture indistinct, Pattern A. Paranota with anterior margin slightly convex, lateral margin very slightly convex. Legs slender, leg 6 tarsus 1.5X as long as femur. Brush setae with forked tips. Sternites of posterior rings (10–18?) with a small, median, rounded, two-lobed tab on posterior edge ( Figs. 4A, 4B), 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. Gonopod telopodite ( Fig. 25) as described by Jeekel (2006).

Female slightly larger than male, legs slender and not swollen, no sternite tabs. Genital aperture with posterior margin raised in wide, almost flat-topped flange, bent slightly anteriorly at corners. Cyphopods not examined.

Distribution: Known from a cluster of three closely adjacent sites in southeastern New South Wales near Jenolan, and a cave site ca. 110 km to the south ( Fig. 31). The fact that the Budthingeroo Creek collection was not in a cave indicates that O. paradoxalis , like a number of other Australian dalodesmids, is only an accidental cave inhabitant.

Remarks: See comment on types for O. cavatica , above.