Arcyphysa gen. nov. (Figs 102–187) Type species: Diplectrona angusta Banks 1939, by present designation. Diagnosis. This genus is distinguished from other Australian Diplectroninae genera by the sharply and almost evenly divided anterolateral dorsal head warts, divided at right angles to the length of the body by a distinct suture, and in male genitalia abdominal sternite IX has one or more elongate, often elaborate, processes apicomedially, and a short, sometimes divided, harpago on each gonopod. Description. Head (Figs 146–150) dorsally with anterolateral warts divided obliquely, both parts similar in size, posterior parts not reaching midline; sutures pronounced. Antennae slender, about as long as forewings, segments cylindrical, with median suture and setae giving crenate appearance (Fig. 152). Maxillary palps (Fig. 103) with segments 2 and 3 about equal length, almost 2x length of segment 1, and about 1.3x length of segment 4, segment 5 exceeding length of all other segments together. Wing venation (Figs 102, 151) as in Arc. diamontona sp. nov.: Forewing fork 2 sessile; median cell length about 1.2x length of discoidal cell. Hind wing f1, f2, f3, and f5 present, median cell open; R1 curving strongly towards margin, as in Diplectrona. Lateral filaments on sternite V present in both sexes, no more than half length of segment, often very short. Male. Abdomen with paired reticulate-walled internal sacs in segments VI and VII (Figs 183–187) about equal length, rarely longer than length of respective segment. Genitalia (Figs 104–115, 117–131, 154–178): Tergites IX and X fused, membranous, somewhat rounded apically with small median incision; sternite IX with upper lateral angle extended posteriorly into processes of various shapes; inferior appendages short, robust, harpago undivided or bifid; phallic apparatus in lateral view gradually curved downward, in ventral view with base abruptly widened, without spines. Female (Figs 116, 179–182). Abdominal sternite VIII well divided mesoventrally and produced posterad, laterodistal angle produced slightly, rounded; segment IX with large dorsoventrally elongate sclerotic cavity, inner surface of which with granular appearance. Distribution. Most species are from north-eastern Australia, but one species is found in central and eastern Victoria. Etymology. Arcyphysa, the name derived from Greek, arkys being descriptive of bubble- or bellows-like appearance of lateral lobes in ventral view of male genitalia, and physa, net or mesh, for the appearance of the internal reticulate-walled sacs of the male. The gender is feminine. Remarks. Relationships of the pair of male genitalic processes above the phallic apparatus and gonopods are often unclear. They are referred to by Mosely (in Mosely & Kimmins 1953) in the description of Diplectrona satana as an 'upper penis-cover forming a pair of processes' and by Neboiss (1979), in D. hystricosa, as a 'pointed process' arising from each lower margin of tergite X. In some species the one or two processes appear clearly to be lobes on the lateral margins of tergite X, in others to be individual structures arising from the apicolateral margins of segment IX. Tergite X is sometimes more or less fused with tergite IX. These variously expressed structures may not be homologues, but to avoid confusion, they are simply referred to as 'apicolateral processes' in the descriptions and key. Neboiss in his draft notes on Australian diplectronines, recognised three separate sets among species that here are assigned to this new genus, Arcyphysa. One set, here termed the Arc. angusta Group, included Diplectrona angusta, Diplectrona hystricosa, Arc. fraserensis sp. nov., and Arc. diamontona sp. nov. Five further species are added now to this group: Arc. candela sp. nov., Arc. lovedayi sp. nov., Arc. naumanni sp. nov., Arc. rossi, and Arc. satana. Neboiss in his preliminary work did not assign Arc. rossi or Arc. satana to any of his groups; however, on the basis of head and general genitalic features they cluster with members of the Arc. angusta Group. The second set, here the Arc. hugginsi Group, included Arc. hugginsi sp. nov., Arc. sybillae sp. nov., Arc. crescentina sp. nov., and Arc. caldera sp. nov.; a fifth species is now added, Arc. carnarvona sp. nov. The third group, here called the Arc. acmea Group, comprised Arc. acmea sp. nov., Arc. anaplasis sp. nov., Arc. tortula sp. nov., Arc. flinti sp. nov., Arc. volsella sp. nov., and Arc. nebo sp. nov. Neboiss proposed, tentatively, that these be recognised as separate new genera. However, features of head, antennae, maxillary palpi, and wings unite all species here assigned to Arcyphysa. They differ in aspects of male genitalia, but, except for the Arc. hugginsi Group (all of which have a pair of parameres basally on the phallic apparatus), no clear synapomorphies can be recognised to unite members. For the present, a single new genus is recognised. The order of treatments here is alphabetic within each of the 3 loose species groups.

Published as part of Wells, Alice & Contents, Arturs Neboiss Table Of, 2018, Australian Diplectroninae reviewed (Insecta: Trichoptera), with description of 21 new species, most referred to a new genus, pp. 1-44 in Zootaxa 4415 (1) on pages 22-24, DOI: 10.11646/zootaxa.4415.1.1, http://zenodo.org/record/1241736