(Figs. 26, 27, 65, 84)
HOLOTYPE WORKER. TL 5.55, HL 1.43, HW 1.53, FC 1.23, CS 1.48, SL 0.80, SI 1 52, SI 2 54, PML 1.13, PW 1.38, PMD 1.50, PMI 2 109, ML 1.35, PTLL 0.43, PTLH 0.55, PTDW 0.53, PPLL 0.43, PPLH 0.59, PPI 72, PPDW 0.53, PT / PP 100.
Mandible with three teeth. In full face view the clypeus anteriorly a strongly vaulted, rugulose to carinulate projection, which markedly exceeds the anterolateral frontal corners; with its anterior margin concave and the anterolateral corners acutely directed antero-ventrad. Head only moderately wider than long (CI 107), preoccipital margin shallowly though markedly concave. Frontal carinae sinuately narrowed towards clypeus (FI 124). Antennal scrobe distinctly surpassing middle of lateral sides of head, anteriorly glossy, distinctly transversely carinulate at rear, posteriorly well demarcated from remainder of head. Genae and ventrolateral sides of head rugose, preoccipital lobes reticulate. Eyes small (EL 0.24, REL 0.16, with 15 ommatidia in the longest row), situated in front of middle of lateral sides of head, dorsal ocular margin not reaching ventral scrobal margin. Head in posterior half distinctly reticulate, inbetween ridges of rugo-reticulation shiny.
Promesonotal shield wider than long (PMI 122), rather flat, distinctly translucently margined, provided with well developed projections concealing lateral sides of mesosoma and propodeal declivity, invisible from above. Propodeal spines long in relation to body size (PSL 0.61) situated above middle of length of declivity, robust and acute, moderately diverging and slightly arcuate when seen from above.
Petiole in lateral view higher than long (PTI 77), with anterior face straight, meeting strongly convex posterior face in an acute angle. Postpetiole nodiform with a small antero-basal tooth.
Gaster entirely microreticulate, basally with additional carinulae. Surface covered with evenly distributed pilosity consisting of shorter decumbent and longer more or less erect arcuate stiff hairs.
Distinctly bicolored with the gaster and appendages brown and remainder of body darkbrown.
WORKERS (n = 10). TL 5.78 5.35 - 6.35, HL 1.38 - 1.60, HW 1.48 - 1.83, FC 1.20 - 1.38, FI 123 - 135, CI 106 - 115, CS 1.43 - 1.71, SL 0.75 - 0.84, SI 1 44 - 52, SI 2 47 - 54, PML 1.05 - 1.25, PW 1.30 - 1.53, PMI 120 - 129, PMD 1.40 - 1.63, PMI 2 107 - 111, ML 1.25 - 1.43, PSL 0.58 - 0.68, PTLL 0.40 - 0.48, PTLH 0.55 - 0.64, PTI 65 - 77, PTDW 0.53 - 0.63, PPLL 0.40 - 0.48, PPLH 0.55 - 0.64, PPI 69 - 77, PPDW 0.51 - 0.63, PT / PP 95 - 104, EL 0.22 - 0.26, REL 0.15 - 0.17, with 14 - 17 ommatidia in the longest row.
ETYMOLOGY
The name refers to the strongly vaulted clypeus.
ADDITIONAL MATERIAL EXAMINED
Queensland : Mount Coot-tha , Brisbane , 16. xii. 1956 ( B. B. Lowery ) . New South Wales : 9 km WRankin Springs , 9. i. 1967 (coll. unknown) ; 25 km NDubbo , Eumungerie SF , 9. ix. 1979 ( B. B. Lowery ) ; Urana golf links , 12. vi. 1979 ( B. B. Lowery ) ; Tallimba , 21. vii. 1979 ( B. B. Lowery ) ; 4 mi EInverell , 22. viii. 1968 ( B. B. Lowery ) ; Trundle , 30. xii. 1963 ( B. B. Lowery ) . (57 workers in ANIC , NHMW , QMBA ) .
DISCUSSION
M. convexius together with the two following taxa forms a cluster within the diversus-group. They all show a similar clypeal structure but may be separated by the different shape and surface of the promesonotal shield, in addition with the size of the eyes. Distributed from the MurrayDarling Basin to SE Queensland.
