Orthorhachis kerewong, 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 : 33-34

Orthorhachis kerewong n. sp.

Figs. 1F, 4C, 5E, 7B, 21; map Fig. 32A

Holotype: Male. Kerewong State Forest , NSW, 31º36'S 152º34'E, 20 November 1978, D. Milledge. In AM, KS94911 .

Paratypes: In AM: 2 males, 1 female , details as for holotype but November 1978, KS94910 ; 1 male , Middle Brother State Forest , NSW, 15 December 1978, D. Milledge, field no. 1556, pitfall trap, KS16112 .

In QM: 1 male, Bruxner Park, 5 km N of Coffs Harbour, NSW, 30º15'00"S 153º06'10"E, 150 m, 1980–81, G. Monteith, rainforest pitfall 104/B1, S83676 ; 2 males, 1 stadium 7 male, 1 stadium 6 male, Poverty Point , SE of Tenterfield, NSW, 1160 m, 1978–79, G. Monteith, rainforest pitfall 94, S83677 .

Other material examined: In QM: 1 male, Point Lookout (upper), New England National Park, NSW, 11 March –11 November 1980, G. Monteith, pitfall, S83678 .

Diagnosis: Metatergites with Pattern B sculpture. Brush setae with mid-length branch. Gonopod telopodite with two processes arising from approximately the same point on the anteromedial surface, the processes 'crossing' with the larger directed laterodistally, the smaller laterobasally.

Description: As for the genus. Male/female approximate measurements: length 18/ 18 mm, midbody prozonite diameter 1.7/ 1.7 mm, midbody width across paranota 2.7/ 2.6 mm. In alcohol, well-coloured specimens dark brown with pale paranotal margins. Antennal sockets separated by 2X a socket diameter. Antennae slen- der, relative lengths of antennomeres 6>(2,3)>(4,5). Collum broadly fusiform with projecting corners, as wide as head and narrower than tergite 2. Metatergite sculpture distinct, Pattern B ( Fig. 7B). Paranota with anterior margin sloping posterolaterally to distinct corner, lateral margin more or less parallel to long axis of body ( Fig. 7B). Legs slender, leg 6 tarsus 2X as long as femur ( Fig. 5E). Brush setae with mid-length branch ( Fig. 1F). Spinnerets partly enclosed by low walls on epiproct ( Fig. 4C).

Gonopod aperture ovoid, slightly wider than long, about one-third the width of the ring 7 prozonite, rim raised posterolaterally. Telopodite ( Fig. 21) short, slender, roughly cylindrical and upright; long setae on posterolateral surface to about one-third telopodite height; branching beginning at three-quarters telopodite height; posterolateral surface of telopodite broadly excavated to base. Solenomere a tapering cylinder, directed posterodistally and slightly medially, then curving distally, the tip bending posteromedially. Medial process small, close to solenomere at base and reaching distally to about one-third solenomere height, bending medially and curving posteriorly, terminating in a broadly rounded tip. Two additional processes arising close together on anteromedial surface of telopodite at just over one-half telopodite height: medial process a tapering cylinder directed laterodistally across anterior surface of telopodite and terminating at same level as medial branch of telopodite; lateral process about one-third the length of the adjacent medial process, more or less triangular, directed laterobasally. Prostatic groove running laterodistally for short distance, then abruptly distally, passing lateral to paired processes to solenomere, terminating at solenomere tip.

Female not significantly larger than male, legs slender and not swollen. Genital aperture with posterior margin raised in wide, more or less flat-topped flange, bent slightly anteriorly at corners. Cyphopods not examined.

Distribution: Disjunct localities in northeastern New South Wales over a linear range of ca. 300 km ( Fig. 32A).

Etymology: Noun in apposition, for the type locality, Kerewong State Forest. The place name 'Kerewong' probably refers to an Australian Aboriginal word, but the spelling 'kerewong' is not recorded in any New South Wales Aboriginal word lists (C. Jarvis pers. comm., A. Lissarrague, pers. comm.). Similar Aboriginal words adopted into English are 'currawong', for one of several cracticine artamid birds, and 'currawang', for the wattle tree Acacia doratoxylon .