Hydrobiosella exilatis sp. nov. Figures 30–32 Holotype. Male: Queensland, Bellenden Ker Range, cable tower 3, 1054m (about 17°16'S, 145°54'E), 25-31 Oct 1981, Earthwatch-Qld Mus. (NMV, T-21480). Paratypes. 3 males (specimen PT-1037 figured), Mt Bartle Frere, 0.5 km N of South Peak, 1500m, 6-8 Nov 1981, Earthwatch-Qld Mus. (NMV). Diagnosis. In lateral view, males of Hydrobiosella exilatis can be distinguished from those of other species in the group by the slender and upturned distal half of segment X; in dorsal view, very flat and appearing broad, length about 1.4 times maximum width, and long and slender harpago of the inferior appendages. Description. Wings similar to H. letti (Fig. 17), length of forewing: male 6.4-7.4 mm. Male. Segment IX in lateral view, length about 1.3-1.4 times width, sub-rectangular, slightly projecting basally (Fig. 31), with a shallow, wide V-shaped notch medially on distal margin (Fig. 32). Segment X length about 1.3-1.4 times width, in dorsal view, ‘tongue-shaped’, broad-based, tapered distally (Figs 30, 31), apex broadly rounded (Fig. 30); in lateral view, narrowed near middle, dilated slightly distally with bulbous apex (Fig. 31). Phallus generally tube-like; with a pair of long, slender, slightly curved, lateral ‘parameres’ arising from the phallus near middle (Figs 30, 31). Inferior appendages in lateral view, with basal segment sub-rectangular, length about 1.8-1.9 times maximum width, harpago slightly longer, length about 1.1 times length basal segment, more slender, length about 3.5 times maximum width, ‘dumb bell- shaped’, narrowed near middle, broadly rounded apically (Fig. 31). Female. Unknown. Etymology. Exilatis – Latin for slender (harpago of inferior appendages). Remarks. Four male specimens of Hydrobiosella exilatis have been collected from two adjacent localities in north-eastern Queensland (latitudinal range 17°16'- 17°24'S). Hydrobiosella excilatas was cited in a checklist (Walker et al., 1995) as Hydrobiosella sp. nov. PT-1037.

Published as part of Cartwright, David I., 2012, Two further species groups and new species among Australian Hydrobiosella Tillyard: new species from south-eastern Australia (Trichoptera: Philopotamidae), pp. 245-258 in Memoirs of Museum Victoria 69 on pages 256-257, DOI: 10.24199/j.mmv.2012.69.03, http://zenodo.org/record/10666102