Body size medium, 4.5 mm in length. Pronotum with subparallel lateral margins (Fig. 38), about as wide as base of elytra. Venter clothed with appressed scales, pappolepidia sparse. Females with elytral declivity distinctly rounded, without sutural tubercle; margin of ventrite 5 entire (Fig. 112).

Body length 4.20 mm to 4.80 mm (X‒ = 4.50 mm, s = 0.20, n = 11). Integument black. Dorsum densely covered with moderate olive to greyish brown appressed scales, some variegation usually present on elytra, but rarely forming distinct patterns; pronotum frequently with obscure lighter lines obliquely converging anteriorly. Femora and tibiae with dense appressed scales concolorous with elytral scales, usually with pale band in distal 1/4 of femur. Tarsi with integument deep orange. Rostrum. Length 0.89 mm to 0.99 mm (X‒ = 0.94 mm, s = 0.04, n = 6), width 0.58 mm to 0.66 mm (X‒ = 0.62 mm, s = 0.03, n = 6), length/width ratio 1.44 to 1.69 (X‒ = 1.52, s = 0.09, n = 6). Epifrons with appressed scales imbricate; setae claviform, decumbent, concolorous; median and lateral carinae not evident. Dorsal carinae arched over antennal insertions. Lateral area ventral of antennal insertions with fine setae and with appressed scales. Antennae. Scapes in repose reaching hind margin of eyes; covered with appressed scales and setae. Funicular segments moderately articulated; segments 1 clavate, about 1.5 times longer than 2; segments 2 clavate, about 1.2 times longer than 3; segments 3 and 4 clavate; segments 5 to 7 subspherical, subequal in length. Pronotum. Length 1.26 mm to 1.39 mm (X‒ = 1.32 mm, s = 0.05, n = 6), width 1.79 mm to 2.26 mm (X‒ = 1.98 mm, s = 0.19, n = 6), length/width ratio 0.83 to 0.91 (X‒ = 0.87, s = 0.03, n = 6); in dorsal view widest in anterior 1/3, lateral margins approximately subparallel (Fig. 38). Anterior margin entire, posterior margin curved. Disc in dorsal view evenly curved, but with obscure median depression in anterior 1/3; appressed scales imbricate; setae claviform, decumbent, concolorous. Postocular lobes poorly developed. Elytra. Length 2.79 mm to 3.52 mm (X‒ = 3.02 mm, s = 0.26, n = 6), width 1.79 mm to 2.26 mm (X‒ = 1.98 mm, s = 0.19, n = 6), length/width ratio 1.43 to 1.62 (X‒ = 1.53, s = 0.07, n = 6). Anterior margin curved posteriad, humeral angles rounded. Appressed scales imbricate. Setae claviform, semi-erect, pale. Striae moderately impressed; interstriae slightly convex. Interstriae 1 at declivity flat in both sexes. Interstriae 3 at declivity flat in both sexes. Elytral declivity curved in females. Apex in lateral view square in males; produced ventrad in females. Thoracic ventrites. Mesoventral process rounded. Mesanepisterna, mesepimera, metanepisterna and metaventrite densely covered with appressed scales. Abdomen. Ventrites sparsely clothed with appressed scales. Apex broadly rounded. Males with ventrite 1 flat; ventrite 5 flat. Females with ventrite 1 flat; ventrite 4 with posterior margin produced into a broad lamina with a strong apical emargination (Figs 112, 113); ventrite 5 disc with shallowly concave, posterior margin entire. Male genitalia. Figs 93, 94. Penis with apex sagittate; ostial region receeding anteriorly, not thickened. Endophallus with gonoporial sclerite very small. Temones 0.78 times as long as pedon. Female genitalia. Figs 95–99. Distal gonocoxites slender, 3.0 times longer than high. Bursa copulatrix long; not constricted anterior of proximal gonocoxite; sclerite lanceolate. Sternite 8 apex rounded, fully sclerotised.

COI. KX191445. 28S. KX192022. ArgK. KX191729. CAD. KX191173.

Holotype. Female (NZAC). Specimen mounted on card teardrop; abdomen removed, dissected and mounted in DMHF on white card below specimen; otherwise entire. Labelled ‘NEW ZEALAND CO / Obelisk Range / Old Man Range / 13 Jan 2014 / SDJ Brown’ [printed, cream card], ‘On Dracophyllum / muscoides cushion / 1590 m / 45.3126°S 169.2102°E’ [printed, cream card], ‘Irenimus taxonomy / and systematics / SDJ Brown / PhD Thesis 2012–2015 / IRE4888’ [printed, cream card], ‘HOLOTYPE / Austromonticola / atriarius / Brown 2017’ [printed, red card]. Genomic DNA extract from enzyme digestion of abdomen: E313 (NZAC). CAD sequence KX191173; COI sequence KX191445; ArgK sequence KX191729; 28S sequence KX192022.

Paratypes. A total of 17 specimens (6 males, 11 females) designated as paratypes, bearing blue paratype label. Paratype specimens deposited in NHM, IACC, LUNZ: 1, NZAC: 2.

CO: North Garvie Mountains, 9 Feb 1985, Barratt BIP, 1200 m, Ex Geum parviflorum (IACC: 1); Old Man Range [45°20.04'S, 169°12.534'E, A], 17 Jan 1965, Kuschel G, Townsend JI, 5000 feet (NZAC: 1); Old Woman Range [45°15.18'S, 169°3.54'E, A], 20 Nov 1974, Watt JC, 1389 m, Litter (LUNZ: 1, NZAC: 5); Rock Peak [44°59.442'S, 168°58.17'E, A], 27 Nov 1974, Dugdale JS, 1430-1460 m, Litter (NZAC: 1); Rock Peak [44°59.442'S, 168°58.17'E, A], 27 Nov 1974, Dugdale JS, 1430-1460 m, Mixed swards and litter (NHM: 2, LUNZ: 1, NZAC: 4); Rock Peak [44°59.442'S, 168°58.17'E, A], 27 Nov 1974, Dugdale JS, 1430-1460 m, Mixed swards litter (NZAC: 1).

Fig. 117. South Island: CO: Garvie Mountains; Old Man Range; Old Woman Range; Crown Range.

Label data: 1200 m to 1590 m (X‒ = 1428 m, s = 76, n = 18). Georeferenced data: 1329 m to 1717 m (X‒ = 1477 m, s = 184, n = 17).

From the Latin adjective rotundus, ‘round, spherical’ for the form of the female elytral declivity; the name is an adjective.

Specimens have been collected from Geum parviflorum Smith, 1805 and Dracophyllum muscoides. The majority of specimens, however, were collected from litter and turf (sward) samples.