Dorylus (Anomma) opacus Forel

Type location Zaïre (Dorylus (Anomma) emeryi Mayr, subsp opaca, n. subsp., Forel, 1909b: 58, workers; raised to species and illustrated by Santschi, 1912b: 154, with male); Bas Congo, the specimens came from the stomach of a Pangolin caught by Solon. Considered a separate species by Santschi (1923) alongside Dorylus (Anomma) titan and Dorylus (Anomma) emeryi .

Forel's (1909b) description of subspecies opaca was - TL 2.8-8.5 mm, but largest workers probably missing; overall smaller than the type. Vary from the type of emeryi (similar sized individuals) by mandibles straighter, with preapical tooth smaller and nearer the apex, by contrast the basal tooth is stronger. Head slightly longer, less narrowed posteriorly, with more obtuse and rounded occipital angles, not incurved at the base. With the larger individuals there is a straight anterior border to the clypeus, in the type this is more extended. No post-clypeal notch. Funiculi perhaps shorter and more slender. Occipital impression deeper and posterior angles obtusely elongated; otherwise similar. The body is entirely matt. The scapes and legs have more profound reticulo-punctate sculpturation - in the type these are subopaque and the appendages are shiny. The pubescence also is more distinct, slightly more abundant and longer. There are a few erect hairs on the dorsal gaster, pedicel and propodeum. Dorylus (Anomma) kohli was noted as more robust, shinier and with shorter appendages. .

Later, Forel (1913h) described the major of opacus - TL 12; HW 3.4; HL 4; as big but a little narrower, and notably more deeply scalloped posteriorly than the type; more entirely matte and strongly reticulo-punctate, with sparse puncturations, larger anteriorly than posteriorly; head also a little flatter than the type and the whole insect distinctly more slender. Specimens from Mayumbé, Zaïre, collected by A. de Briey.

Santschi (1912b) described the major and his description is at .

Wheeler (1922) reporting opacus, from Zaïre (Ngayu, Lang & Chapin), noted "that the sides of the heads of the largest workers are less convex than indicated by Santschi's figure and like that which he gives of D. emeryi, though slightly narrower and much more deeply excavated behind. The preapical tooth of the mandibles is lacking in the largest". Note, the drawing (right) from Bolton (1990c) was not accompanied by any information or description.

Wheeler (1922) listed a Cameroun collection at Mundame by Conradt; also from Ghana (at Aburi, F. Silvestri); Congo and Fernando Po (by Conradt); Gabon (by F. Faure)(Wheeler, 1922). From Guinea, Bernard (1952) reported several lowland findings of the typical Cameroun form: abundant at G'ba; Yanlé; N'Zo, primary forest at 700 m (numerous workers, Lamotte, colony, Villiers); Zouépo, 1215 m, forest (Lamotte).

Raignier & Van Boven (1955) examined specimens they collected at three locations in Yangambi. They noted - TL largest 12.56, CI 95-96, SI 44; head with posterior angles divergent from above; mandibles straight with basal tooth, longer than in congolensis; antennal funiculus segment 2 shorter than 1 or 3; petiole about as long as wide, head, thorax and basal gaster matt, rest of gaster semi-matt, colour black, sides reddish.

The photomontage is collated from http://www.antweb.org/specimen.do?name=casent0172645&shot=p1&project=null, collected at Cross River, Nigeria, by Caspar Schöning, 1.ii.2005; presumably not a major as the mandible has subsidiary teeth.