Ocymyrmex shushan sp. n.

(Fig. 31)

Holotype worker. TL 6.7, HL 1.66, HW 1.58, CI 95, SL (antennae missing), PW 1.02, AL 2.14.

Anterior clypeal margin with a small but distinct median semicircular impression, which is flanked by a pair of short, acute teeth. Maximum diameter of eye 0.34, about 0.22 x HW. Sides of head behind eyes evenly convex and narrowing, rounding into the occipital margin with which, if it were not for the median impression in the latter, they would form a very regular arc. In profile the posterior pronotum and anterior part of mesonotum high and strongly convex, forming a dome-like outline above the level of the mesothora-cic spiracles. Pronotum in front of this and mesonotum behind it sloping away evenly, increasing the dome-like appearance. Posterior portion of mesonotum and dorsum of propodeum more or less flat in profile, the latter rounding broadly into the convex declivity. Metapleural lobes small and low, rounded. Peduncle of petiole flat dorsally but sinuate ventrally. Petiole node in profile low dome-like, smoothly and evenly rounded. Postpetiole in profile subglobular, Fig. 31. In dorsal view the petiole node much broader than long, all surfaces smoothly rounded; postpetiole slightly longer than broad. Base of first gastral tergite constricted and forming a neck behind the postpetiole. Dorsum of head finely and densely longitudinally rugulose, the rugulae diverging away from the midline posteriorly. Ground-sculpture between the rugulae a strong and conspicuous punctulation which in places seems as strongly developed as the rugular sculpture. Pronotum with a few strong transverse costulae on the cervical shield but behind this the costulae which arch up from the sides become very faint or vestigial when traversing the dorsum. Between the mesothoracic spiracles and extending for a short distance forwards and backwards is a patch of low longitudinal rugosity. Remainder of alitrunk and propodeal declivity transversely rugose or costulate. Petiole node smooth and shining, the anterior peduncle with some very faint transverse striae. Postpetiole unsculptured. Body everywhere lacking the conspicuous punctulate ground-sculpture which is so well developed on the head. All dorsal surfaces of head and body with numerous hairs, those on the first gastral tergite shorter and sparser than those on the alitrunk. Colour uniform bright orange.

Holotype worker, South West Africa: Gobasis, 17. xii. 1933 (J. Ogilvie) (BMNH).

This bright orange species is characterized amongst forms with both a gastral constriction and an impressed clypeal margin by the strongly convex anterior portion of the dorsal alitrunk and the shape of the petiole, as described above.