wheeler: ants of the genus opisthopsis. 357 



Pilosity as in haddoni, lacking on the thorax and petiole. 



Black; sides and anterior portion of head, thorax, coxae, petiole, 

 first gastric segment and in some specimens the extreme base of the 

 second, castaneous brown. Antennal scapes, first funicular joint and 

 legs yellowish brown, femora darker in the middle. Mandibles 

 yellow, with black teeth. Eyes pearl-gray. 



Described from eight specimens taken in three colonies of 0. haddoni 

 at Koah, Queensland, October 29. Like the specimen of 0. maurics, 

 they had probably been reared from kidnapped larvae or pupae. 



12. Opisthopsis diadematus, sp. nov. 

 Plate 3, fig. 20, 21. 



Worker. Length 4-5 mm. 



Head very convex dorsally, ventrally and laterally, so that the 

 cheeks have a swollen appearance. Posterior border straight. Eyes 

 rather small and far apart. Mandibles with slightly convex external 

 borders, the apical borders not very obHque, their five teeth small 

 and subequal. Clypeus broader than long, indistinctly carinate. 

 Thorax rather robust, with well-marked promesonotal and mesoepin- 

 otal sutures; the base and declivity of the epinotum subequal, the 

 former slightly concave, the latter abruptly sloping and concave, the 

 angle between them blunt but prominent. Petiolar scale of the usual 

 shape, nearly as high as the epinotal angle. Gaster rather large. 



Shining, very finely shagreened and sparsely and finely punctate; 

 mandibles more coarsely punctate. 



Hairs pale yellow, sparse, erect; absent on the thorax and petiole. 



Orange-yellow, head not paler in front; funicuU, except their basal 

 joint, space between the eyes and including the vertex and occiput, 

 gastric segments behind the second, all but the base of the second 

 above and in some specimens a spot on each side of the first segment, 

 black. Posterior borders of gastric segments pale brown. The yellow 

 of the anterior gastric segments is distinctly paler than that of the 

 legs. Palpi dark brown. Eyes dark brown or black. 



Described from seven workers taken at Townsville, Queensland, on 

 the bark of Eucalyptus trees and undoubtedly belonging to several 

 colonies. 



