Hydrobiosella bandabanda sp. nov.

Figures 1, 2, 2a, 3, 3a, 4, 4a, 38, 38a

Holotype. Male. Victoria, Toorongo Falls, 7 km NE of Noojee, (about 37°51'S, 146°00'E), 27 Nov 1981, J. Morse & A. Neboiss (NMV, T- 21392).

Paratypes. Victoria. 4 males (specimen CT-593 figured), 1 female (specimen CT-594 figured), collected with holotype; 7 males (specimen PT-581 figured), 2 females (specimen CT-612 figured), Newlands Ck, Upper Thomson R. (about 37°37'S, 146°10'E), 26 Feb 1978, TR Survey (NMV) .

Other material examined. Victoria. 2 males, Falls Ck Ski Village, 26 Mar 1957, A. Neboiss ; 1 male, Cumberland Falls, SE of Marysville, 7 Jan 1971, A. Neboiss ; 1 male, Baw Baw Ski Village, 4900 ft, 8 Jun 1974, J.C .; 1 male, Cement Ck, Mt Donna Buang Rd, 3 Mar 1980, J. Dean ?; 1 male, small ck 1 km N Rum Ck, 9 Nov 1983, D. Cartwright (NMV) .

Diagnosis. Males of Hydrobiosella bandabanda can be distinguished from those of other species in the group by a central dorsal ridge or groove with a pair of lateral acute processes on segment X.

Description. Wings typical of the genus (Fig. 1), similar to those of H. bispina (Cartwright, 2010, fig. 1). Length of forewing; male 6.7–9.1 mm, female 7.2–9.3 mm.

Male. Segment IX with a shallow, wide V-shaped notch medially on distal margin (Figs 4, 4a). Segment X in dorsal view, a ‘tongue-shaped’ process, with sides almost parallel, a pair of small knobs baso-laterally, tapered distally and with a central dorsal ridge or groove bearing a pair of lateral acute processes (Figs 2, 2a), length about 3-3.5 times width; in lateral view broad-based, slightly curved (Fig. 3), or straight (Fig. 3a) slender in middle, usually slightly dilated distally with a sub-apical ‘knob’ (Fig. 3), sometimes without ‘knob’ (Fig. 3a). Phallus generally tube-like, robust, with a pair of sub-apical spines and two smaller spines basally (Figs 2, 2a, 3, 3a). Inferior appendages in lateral view, with basal segment broadest near middle, length about twice maximum width; harpago shorter, length about half length basal segment, more slender, length about twice maximum width, apex broadly rounded (Figs 3, 3a).

Female. Genitalia typical of genus, with a small acute projection on sternite IX meso-distally (Figs 38, 38a).

Etymology. Bandabanda – Australian aboriginal word for split or broken open (dorsal groove on segment X).

Remarks. Hydrobiosella bandabanda shows slight variation among the 21 specimens collected from 7 localities in eastern-central and north-eastern Victoria (latitudinal range 36°52'– 37°51'S).