Ocymyrmex ankhu, Bolton, B., 1981

Bolton, B., 1981, A revision of six minor genera of Myrmicinae (Hymenoptera: Formicidae) in the Ethiopian zoogeographical region., Bulletin of the British Museum (Natural History) Entomology 43, pp. 245-307 : 265

Ocymyrmex ankhu sp. n.

Holotype worker. TL 10.2, HL 2.34, HW 2.35, CI 100, SL 2.30, SI 98, PW 1.50, AL 2.96.

Anterior clypeal margin entire, without a strong median notch flanked by a pair of teeth but only with a tiny erosion of the apron where the weak median clypeal carina runs into it. Maximum diameter of eye 0.42, about 018 x HW, the eyes conspicuously failing to break the outline of the sides of the head in full-face view. Sides of head extremely weakly divergent anteriorly, rounding broadly and evenly into the occipital margin which is shallowly convex on each side of a median indentation. Alitrunk in profile with the promesonotum low and very shallowly convex, almost flat dorsally but with the posterior half of the mesonotum sloping more steeply downwards. Propodeal dorsum almost flat, with an exceedingly shallow depression in the surface just in front of the level of the spiracle. Posteriorly the propodeal dorsum rounding broadly and evenly into the shallowly convex declivity. Metapleural lobes low and truncated posteriorly. Petiole in profile large, broadly dome-like and rounded, the anterior peduncle without trace of a ventral process. In dorsal view the petiole node very slightly longer than broad, rounded and with evenly convex sides. Postpetiole in dorsal view broader than long. Base of first gastral tergite no broader than the postpetiole but not constricted to a narrow neck; instead the sides diverge quickly and evenly from the base. Dorsum of head between eyes with faint superficial vestiges of fine and quite dense rugular or costulate sculpture which in places is almost effaced. Ground sculpture absent except for the faintest remnants of a minute superficial reticulation, the surface mostly smooth and glossy and the scattered hair pits quite clearly visible. Occipital region of head mostly smooth but a narrow strip in front of this with feeble transverse sculpture. Pronotal dorsum mostly smooth, with marginal remnants of fine arched rugulae and vestiges of the longitudinally sculptured area between the mesothoracic spiracles just visible. Remainder of dorsal alitrunk very finely and feebly transversely rugulose, with a tendency for the rugulae to fade out centrally. Sides of alitrunk more strongly and more sharply rugulose or costulate, weaker on the pronotal sides than elsewhere. Petiole, postpetiole and gaster unsculptured except for a fine superficial reticulation. Dorsal surfaces of head, alitrunk, petiole and postpetiole with numerous strong reddish brown hairs. Basal half of first gastral tergite hairless but more apically the segment with 1 - 2 very short, inconspicuous hairs. Colour a uniform rich orange-brown, the gaster very slightly lighter in shade than the head and alitrunk.

Paratype workers. TL 9.7 - 10.2, HL 2.26 - 2.34, HW 2.22 - 2.34, CI 97 - 101, SL 2.22 - 2.34, SI 95 - 102, PW 1.40 - 1.48, AL 2.84 - 2.92 (7 measured). Maximum diameter of eye 0.42 - 0.44, about 0.18 - 0.19 x HW. As holotype.

Holotype worker, Angola: 5 miles [8 km] E. of Vila Arriaga, 1000 m, 21. v. 1958 (E. S. Ross & R. E. Leech) (CAS, San Francisco).

Paratypes. 7 workers and 1 female with same data as holotype (CAS, San Francisco; BMNH; MCZ, Cambridge).

O. ankhu is closest related to velox and shares most of its diagnostic characters. However, ankhu is more or less uniformly coloured and has the body pilosity reddish brown. In velox the body is conspicuously tricoloured and the hairs are usually white.