354 bulletin: museum of comparative zoology. 



This form is so close to pidus that it might properly be regarded as 

 a subspecies or variety of that species. The specimens which I took 

 at Enoggera and Sunnybank were running about on Eucalyptus trunks 

 and on the ground. Mjoberg found the species nesting in clay about 

 the roots of trees at Atherton and Cedar Creek. 



9. Opisthopsis HA.DD0NI Emery. 



Plate 2, fig. 11-16; Plate 3, fig. 29. 



Opisthopsis haddoni Emery, Rev. Suisse zool., 1893, 1, p. 226, S ; 

 Emery, Mem. R. accad. sci. ist. Bologna, 1896, ser. 5, 5, p. 776; 

 Froggatt, Agric. gaz. N, S. W., 1905, p. 28; Viehmeyer, Abh. ber. 

 K. zool. anthr. ethn. mus. Dresden, 1912, 14, p. 23; Forel, Ark. 

 f. zool., 1915, 9, p. 95, ^ ; Crawley, Ann. mag. nat. hist., 15, 1915, 

 ser. 8, 15, p. 135, ^ . 



TVorker. Length 3-5.5 mm. 



Head evenly convex dorsally and ventrally, with straight posterior 

 border, in large workers with very feebly convex, in small workers 

 with straight sides. Mandibles 5-toothed, their external borders 

 rather straight. Clypeus carinate at the base. Thorax and petiole 

 shaped much as in rufithorax, the former rather short, with blunt 

 epinotal angle. 



Shining; head and thorax more opaque than the gaster and more 

 distinctly shagreened. Mandibles shining, sparsely punctate. 



Hairs whitish, sparse, erect, blunt, absent on the thorax and petiole. 



Clear orange-yellow, vertex and occiput of head a little darker, 

 cheeks, clypeus, and mandibles more lemon-yellow, the teeth of the 

 mandibles brown. Gastric segments behind the second, palpi, and 

 funicular joints, except the first, black. Terminal tarsal joints brown 

 or reddish. Eyes black. 



Female. Length 8-9 mm. 



Head shaped like that of the worker but a little broader, a little 

 narrower than the thorax through the wing-insertions, with nearly 

 straight sides. Mandibles 6-toothed. Mesonotum as broad as long, 

 epinotum with distinct base and declivity, the former short and con- 

 vex, the latter vertical and concave in profile. Petiole as in the 

 worker, but with its superior border feebly notched in the middle. 

 Gaster rather large, elongate elliptical. Wings moderately long, with 

 well-developed, triangular discal cell. 



