Type material: Holotype male, 27 km E Kimba, S. Aust., 25.x. 1982, on Eremophila scoparia, S.Barker, SAMA I 21 708. Allotype female, same data as holotype, SAMA I 21 709. Paratypes: S.Aust.: female, Banyong station via Morgan, 17.xii. 1977, on flowering mulga, R.Patterson, SAMA; 7 males, 5 females, same data as holotype, SAMA; 4 males, 2 females, 30 km E Kimba, on Eremophila scoparia, xi. 1989, J.Bugeja & A. Sundholm; 1 male, 1 female, dead on salt lake nr Sinclair Gap, Eyre Pen. 33 o 11 ’ 33 ” S. 137 o 05’ 34 ” E. iii. 1996, P. Hudson, SAMA; 1 female, dead on Sinclair Gap salt lake 33 o 122 ’ 50 ” S. 137 o 05’ 22 ” E. 7.ix. 1996, P. Hudson, SAMA.; 1 female, 14.29 km N of Kalanbi, 29.x. 2003. J. Bugeja, A. Sundholm, on flowers of Eremophila scoparia; 2 males, 2 females, Wirrula district, 29.x. 2003, A.Sundholm & J. Bugeja, ASSA; 1 female, Googs track, Yumbarra Conservation park, on flowers of Eremophila scoparia, 3.x. 2004, A. Sundholm, R. de Keyzer, A. Scott. ASSA; 1 male, Dangali Conservation park, 0.6 km W. Mooraninna Dam, 27.x. 2004, on flowers of Eremophila scoparia, A. Sundholm, R. de Keyzer, A. Scott, ASSA; 4 males, road between Whyalla & Kimba, 28 / 29.x. 2004, on flowers of Eremophila scoparia, A. Sundholm, R. de Keyzer, A. Scott., ASSA; 1 female, Eyre Highway Lake Gilles Conservation Park, 4.xi. 2004, on flowers of Eremophila scoparia, A. Sundholm, R. de Keyzer, A. Scott., ASSA. N.S.W.: 3 males, Tarawi Nature Reserve, 26.x. 2004, on flowers of Eremophila scoparia, A. Sundholm, R. de Keyzer, A. Scott, ASSA.
Size. Holotype, 13.2 x 5.3 mm. Males, 12.0 x 4.4–14.5 x 5.7 mm. Females, 12.8 x 4.9–16.3 x 6.3 mm.
Description. Colour: Head, antennae, pronotum, ventral surface and legs bronze. Elytra yellow with the following black markings: narrow basal margin; premedial fascia, ends projecting anteriorly not reaching margins, in some specimens reduced to a spot on each elytron; postmedial fascia reaching margin; preapical spadeshaped mark extending to apex, all marks connected along suture but not connected to scutellum.
Shape & sculpture: Head heavily punctured, deep median sulcus, very short mouthparts. Antennomeres: 1–3 obconic; 4 halftriangular; 5–11 triangular. Pronotum closely punctured, anterior margin projecting slightly medially with prominent collar, basal margin bisinuate, basal notch glabrous without punctures closer to margin than middle, deep, round median fovea extending to anterior margin as impressed line, laterally parallelsided at base, rounded out to widest part medially, rounded and narrowed to apex. Scutellum scutiform, indented posteriad to anterior margin, impunctate. Elytra punctatestriate, intervals markedly convex, laterally angled outward from base, rounded at humeral callus, concave, rounded postmedially and narrowed to unispinose apex, minute, acute sutural spine. Ventral surface shallowly punctured, edges of abdominal segments glabrous, setose, long setae. S 7 rounded both sexes.
Aedeagus: Parameres slightly angled outwards from basal piece, rounded after middle, parallelsided to apex then flattened; penis pointed (Fig. 1 a).
Remarks. I mistakenly confused this species with C. turneri (Barker) 1983 from NSW. The paratypes I designated of C. turneri were this species. The head, pronotum, ventral surface and legs of C. turneri are coppery and the male genitalia differ (Fig. 1). This species is a member of the C. convexa (Carter) species group.
Distribution. Upper Eyre Peninsula South Australia and southwestern New South Wales.
Etymology. Named for Archie McArthur, Adelaide.