f. Fourth and fifth segments of the first and second pair of tarsi are black. g. The yellow bands of the abdominal segments occupy a third of the segment (fig. 165). G. MORSITANS Westw. gg. The yellow band on each segment of the abdomen occupies a sixth of the segment. G. LONGIPALPIS Wied. ff. Tarsi of the first and second pairs of legs wholly yellow. _G. pallidipes_ Austen cc. Rays of the arista not plumose; only one or two sternopleurals; base of the media not strongly bowed down; apical cell opens at or very near the apex of the wing. d. Vein R_{4+5} without setæ at the base; palpi about as long as the proboscis. e. Arista pectinate (i.e. rays on one side only), the rays often undulate; two yellow sternopleurals often difficult to detect; vein M_{1+2} only slightly bent, the apical cell hence wide open. The horn fly, H. IRRITANS (= _Lyperosia serrata_) and related species. Widely distributed (figs. 167, 168). HÆMATOBIA R. D. not B. B. [Illustration: 165. Glossina morsitans. (×4.) After Austen.] ee. Arista also with rays below; vein M_{1+2} more strongly bent, the apical cell hence less widely open. f. Palpi strongly spatulate at the tips, lower rays of the arista about six in number, B. SANGUINOLENTUS. South Asia. BDELLOLARYNX Austen ff. Palpi feebly spatulate; apical cell of the wing narrowly open slightly before the tip; sternopleurals black, anterior bristle sometimes absent. H. ATRIPALPIS. Europe. HÆMATOBOSCA Bezzi dd. Vein R_{4+5} with setæ at the base.[L] e. Veins R_1 and R_{4+5} with setæ at the base; two equally prominent sternopleural macrochætæ; arista with rays both above and below; palpi as long as the proboscis; apical cell of the wing wide open. L. TIBIALIS. (_Hæmatobia_ B. B. not R. D.). LYPEROSIOPS Town. ee. Only vein R_{4+5} with basal setæ; anterior sternopleural macrochæta wanting; arista pectinate. f. Palpi as long as the proboscis, the latter stout, with fleshy terminal labellæ; apical cell narrowly open; sternopleural macrochætæ black. S. MACULOSA from Africa and related species from Asia. STYGEROMYIA Austen ff. Palpi much shorter than the proboscis, the latter pointed at the apex, without fleshy labellæ; apical cell of the wing wide open. S. CALCITRANS, the stable fly and related species. Widely distributed in both hemispheres (fig. 110). STOMOXYS Geof. aa. Proboscis neither slender nor elongate, the labellæ fleshy and not adapted for piercing.