Atrophotergum bonhami, Mesibov, Robert, 2004

Mesibov, Robert, 2004, A new genus of millipedes (Diplopoda: Polydesmida: Dalodesmidae) from Tasmania, Australia with a mosaic distribution, Zootaxa 480, pp. 1-23 : 9-10

Atrophotergum bonhami n. sp.

Figs. 4, 7 ; map Fig. 12

Holotype: Male, Henry Somerset Orchid Conservation Area, Tasmania, DQ506298 (41°16’53”S, 146°24’36”E), 50m, 13.vii.1994, R. Mesibov, QVM 23:25277.

Paratypes: 2 males, details as for holotype, AM KS87134, 1 dissected; 2 males, Latrobe Creek, DQ528365 (41°13’16”S, 146°26’12”E), 60m, 25.vi.1997, R. Mesibov, QVM 23:25283.

Other material examined: 17 males. See Appendix for details.

Diagnosis: Distinguished from other Atrophotergum spp. by the unique form of the gonopod.

Description: As for genus. Males 8–10 mm long, 0.7–0.8 mm in maximum vertical diameter. In alcohol, most specimens are pale with reddish antennae. As in A. silvaticum n. sp., dark patches are sometimes visible near ozopores.

Gonopod telopodite ( Fig. 7 ) gently curved posteriorly. Solenomerite more or less straight but bent posteriorly and laterally from the anterodistal corner of the SF; the process divided at about two­thirds its length into an anterior branch containing the terminus of the prostatic groove and a shorter, blunter branch arising posteromesally. The outer portion of the SF curved laterally and posteriorly; PDC thickened at its tip, extending basally and laterally as a short, flat process; PBC curving distally. TT bent slightly laterally, its tip extending distally beyond the PDC. MES a pair of short, rod­like, pointed processes curved more or less in parallel posteriorly and laterally, terminating anterior to the LES. LES more or less parallel to long axis of telopodite, with its distal edge angled so that the blunt, thickened anterior corner is considerably more distal than the posterior corner.

drawings; dashed line marks course of prostatic groove.

Anterior sternal process on somite 17 ( Fig. 4 A) a low eminence; the anterior portion of the posterior process a low ridge, somewhat excavated mesally, the posterior portion a short, finger­like structure directed ventrally.

Distribution and habitat: In leaf and woody litter in dry and wet eucalypt forest over ca. 400 km 2 in north central Tasmania, from near sea level to at least 300 m ( Fig. 12 ). Also found in forest plantations within this area ( Bonham et al. 2002 [as ‘genus A, sp. 5’]). Etymology: Named in honour of the Tasmanian malacologist Kevin J. Bonham, who collected many of the known specimens of this inconspicuous species.

Figures

FIGURE 7. Gonopod of A. bonhami n. sp. Posterior and slightly mesal (left) and lateral (center) drawings of left gonopod telopodite of male, QVM 23: 25364. Lateral and slightly ventral SEM (right) of right gonopod telopodite of paratype male from QVM 23: 25277 Setation not shown in

FIGURE 12. Known localities in Tasmania of Atrophotergum bonhami n. sp. (open squares), A. montanum n. sp. (filled squares), A. pastorale n. sp. (crosses), A. silvaticum n. sp. (filled triangles), A. sodalis n. sp. (filled circles) and A. wurrawurraense n. sp. (open triangles). The top map shows overall distributions, while the bottom map shows localities and major streams within the rectangular area marked on the top map.