Discothyrea crassicornis, Clark, 1926

Clark, J., 1926, Australian Formicidae., Journal of the Royal Society of Western Australia 12, pp. 43-52 : 46-47

Discothyrea crassicornis n.sp. (Pl. VI, 4 and 4a.)

Worker: Length 1.8mm.

Bufo testaceous; mandibles, apical joints of the antennae and legs yellow. Hairs whitish, short and sparse on the whole body. Pubescence whitish, short, very fine and abundant everywhere, longest on the gaster.

Opaque. Densely and finely punctate-reticulate on the head, more coarsely so on the thorax and abdomen, node coarsely punctate above.

Head longer than broad, broader behind than in front, the occipital border and sides convex, the posterior angles rounded. Frontal carinae short and erect, dilated behind, truncate behind the dilation and confluent to the middle of the head. Clypeus produced, widely convex in front, feebly but distinctly crenulate. Mandibles moderately long, subtriangular, the terminal border with a sharp cutting edge which shows no traces of teeth, ending in a somewhat long sharp point. Eyes amali, flattened, placed slightly in front of the middle of the sides. No traces of ocelli. Antennae 9-jointed, short and very thick; scapes short, extending to about the occipital third of the head, club-shaped, fully three times thicker at the apex than at the base; first joint of the funiculus as broad as long, cylindrical, five times longer than the second, the second to seventh mueh broader than long, subequal, the seventh fully three times broader than the second, the apical joint very large, about two and one half times longer than broad, and mueh longer than the remainder of the funiculus. Thorax fully twice as long as broad at the pronotum; one and one half times broader through the pronotum than through the epinotum; pronotum convex in front and on the sides, feebly concave in the mesonotal region; there are no traces of mesonotal sutures; the posterior margin of the epinotum slightly concave and marginate, the angles bluntly produced; in profile rounded and convex above, the epinotal declivity abrupt, almost at a right angle with the dorsum, the sides marginate. Node, from above, two and one half times broader than long, all four sides of the dorsum convex; in profile it is twice as high as long, rounded above, the anterior face almost straight, the ventral surface in front with a short blunt tooth-like projection, to the front edge of which is attached a keel-like, translucent lamella. Postpetiole slightly broader than long, much broader behind than in front, the anterior border and sides rounded; in profile it is eonvex and rounded above, the ventral surface with a transverse, tooth-like process in frontA strong constriction between the two segments of the gaster. The second segment is one fourth broader than long, broader in front than behind, strongly rounded and eonvex, narrowing rapidly to the small apical segments which are placed below. Legs short and stout.

Hab.: Western Australia , Manjimup (J.Clark) .

Two examples under a rotten log.

The occurrence if this insect in South West Australia is of great interest, as it shows the wide distribution of this aiuient genus. This species appears to be intermediate between D. clavicornis Emery , from New Guinea, and D. antarctica Emery , from New Zealand.