Genus Mesodiplatys Steinmann, 1986, stat. nov.

Type species: Diplatys nana Burr, 1914, by original designation.

Diagnosis. Head differentiated into frontal and occipital regions; eyes large and prominent (Figs. 1, 13, 14). Metaparameres roughly trapezoidal in shape, widened proximally, apex without cleft or armament, more or less tapered apically to form small outgrowth (Figs. 10, 12, 18). Virga divided into unpaired short and dilated proximal part and paired long, simple and whip-like distal parts; complicated accessory sclerites absent (Figs. 10, 11, 18).

Composition. Mesodiplatys nanus (Burr), M. gracillimus (Hincks), M. longicornis (Hincks), M. major (Brindle), M. mucronatus (Hincks), M. raharizoninai (Brindle), M. olsufiewi (Borelli), M. insularis (Borelli) .

Notes. The genus Mesodiplatys was originally described as a subgenus of the genus Haplodiplatys Hincks, 1955 . The subgenus Haplodiplatys was described as monotypic, containing only H. niger Hincks, 1955 from Kumaon, Northern India (Hincks 1955). Haplodiplatys niger is morphologically quite distinct and distant from the representatives of the genus Mesodiplatys: “Closely related to Diplatys but differing in the entirely simple head, small eyes, gynecoid abdomen, simple, cylindrical forceps and simple ultimate tergite" (Hincks 1955, p. 17), excluding the presence of the metaparameres with simple apices. Therefore, Mesodiplatys should not be included in Haplodiplatys .

Mesodiplatys nanus, M. gracillimus, M. longicornis, M. major, M. mucronatus and M. raharizoninai were consigned to the subgenus Mesodiplatys by Steinmann (1986). Mesodiplatys olsufiewi was assigned to the subgenus Haplodiplatys (Steinmann 1986), but the structure of the male genitalia in this species (Brindle 1966) is completely similar to that of Mesodiplatys . The structure of the male genitalia of M. insularis was not illustrated, but according to the original description (Borelli 1932), the metaparameres of this species are simple and the branches of the virga are very long.

In the original description of Mesodiplatys, the virga are incorrectly reported as "... without unpaired but with very long paired sections" (Steinmann 1986, p. 171). The distinct unpaired short proximal part of the virga is clearly visible in all representatives of the genus Mesidiplatys (Figs. 10, 11; also see Figs. 17, 19 in Hincks (1955), and Figs. 8–13 in Brindle (1966)).

Several African Diplatys spp. have long, whip-like distal parts of the virga: D. aethiops Burr, D. bicolor (Dubrony), D. burri Hincks, D. longipennis Brindle, D. gedyei Hincks, D. rotundicollis Hincks, D. schoutedeni Hincks, and D. simplex Hincks. All of them strongly differ from the representatives of the genus Mesodiplatys by the structure of the metaparameres, which are apically toothed or cleft (Hincks 1955; Brindle 1966, 1969, 1973). Moreover, some species (for instance, D. aethiops, D. burri, D. gedyei, and D. longipennis) are characterized by a specialized structure of the virga, different from that of Mesodiplatys (Hincks 1955; Brindle 1969). Diplatys saxeus Brindle, 1982, described from Zimbabwe, is similar to species of Mesodiplatys in the simple shape of the metaparameres and the long whip-like distal parts of the virga, but differs in having small eyes, shortened tegmina and reduced wings (Brindle 1982).