238 Ants f'rotn \ortIi and Sou/h-west Australia i(:c. 



Head finely reticulate, the sculpture almost concealed by 

 the pubescence ; o|)a(]ue (shining and striate in guerlni). 

 Scapes finely reticulate. Thorax and pedicel (except the 

 apical half of all the spines) coarsely reticulate-rugoso, shining 

 between the reticulations. On the lower half of the back of 

 pedicel, between the spines, the rugosities take a transverse 

 (.iireclion. Legs finely reticulate. Gaster very finely reti- 

 cul:itc-punctate,the sculpture almost hidden by the pubescence. 

 Krect hairs on head yellowish, on pro- and e()inotuin darker, 

 on gaster golden. Pubescence on head very thick, silver- 

 grey. Of the thorax, tiie epinotum only is pubescent, 

 similarly to the head. On the gaster the pubescence is 

 pule golden, merging into grey underneath. The femora and 

 tibia? have a slight silvery pubescence. 



Stapleton, N.T., 22. xii. 12 {Bill). $ . 



No. 12. Polyrhachia delicata, sp. n. 



$ . — L. 5"5-6 mm. 



Mandibles 5-dentate, shining, with minute piligerous 

 ])oint3 ; finely striate at base. Clypeus carinate, produced 

 anteriorly into a slight lobe with a straight edge and pointed 

 angles. Frontal area distinct, in the form of an equilateral 

 triangle. Frontal carinas long, very slightly convergent 

 behind (similar to thrina.r). Head longer than broad, wider 

 behind than in front, occipital border not so rounded as in 

 thrinax] eyes prominent, placed in the posterior third of 

 sides. Thorax fairly regularly curved to the spines, pro- 

 notum sliouldered, with very small teeth at the angles. Pro- 

 mesonotal and meso-epinotal sutures distinct ; mesonotum 

 broader in front ; the two surfaces of epinotum equal in 

 length, the declivous surface convex ; the epinotum with two 

 straight narrow spines, two-thirds as long as the basal surf ace 

 of epinotum ; node of pedicel with a thick and fairly high 

 scale, in the centre of which is a long straight spine slightly 

 directed backwards ; in advance of this spine on each side 

 is a shorter sharp spine directed outwards. The central 

 spine, which is acuminate, not notched as in thrinax, is 

 nearly three times as long as the lateral spines. Gaster 

 round, slightly longer than broad. 



Whole of head, thorax, and pedicel densely and finely 

 reticulate, clypeus very finely so; Iiead more rugose between 

 the frontal carinas and eyes, pronotum more or less longi- 

 tudinally so ; declivous surface of epinotum shining, only 

 faintly and superficially reticulate; gaster shining, very 

 faintly and superficially reticulate. 



Pilosity practically nil ; a few erect hairs on the mandibles, 



