Polyrhachis delicata , Crawley W. C., 1915

Crawley W. C., 1915, Ants from north and south-west Australia (G. F. Hill, Rowland Turner) and Christmas Island, Straits Settlements. Part 2, Ann. Mag Natur. Hist. 15, pp. 232-239: 238-239

publication ID


persistent identifier


treatment provided by


scientific name

Polyrhachis delicata

sp. n.

No. 12. Polyrhachis delicata  HNS  , sp. n.

☿ . - L. 5.5 - 6 mm.

Mandibles 5-dentate, shining, with minuta  piligerous points ; finely striate at base. Clypeus carínate, produced anteriorly into a slight lobe with a straight edge and pointed angles. Frontal area distinct, in the form of an equilateral triangle. Frontal carinae long, very slightly convergent behind (similar to thrinax  HNS  ). Head longer than broad, wider behind than in front, occipital border not so rounded as in thrinax  HNS  ; eyes prominent, placed in the posterior third of sides. Thorax fairly regularly curved to the spines, pronotum shouldered, 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 surface 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  HNS  , 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; head more rugose between the frontal carinæ and eyes, pronotum more or less longitudinally 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, clypeus, and between the front carinæ; clypeus slightly pubescent; gaster with a fine pubescence.

Red-brown, head and gaster darkest.

Darwin, N.T., 16. iv. 13 (Hill). ☿ .

Christmas Island, Straits Settlement.

A few ants were collected in March 1914, and kindly submitted to me by my friend Mr. D. Ward Pinkney. They are as follows :-