oo. Presutural intraalar present, if absent, then the ventral sclerites broadly exposed or the fifth ventral sclerite vestigial; base of the antennæ usually above the middle of the eye; arista bare; at least two posthumerals and three posterior intraalars present. Parasitic on caterpillars, etc. TACHINIDÆ SYNOPSIS OF THE PRINCIPAL GENERA OF THE MUSCIDÆ OF THE WORLD a. Proboscis long, directed forward, adapted for piercing, or oral margin much produced, snout-like. b. Oral margin produced snout-like; vibrissa placed high above the oral margin; antennal arista either pectinate or more or less plumose. c. Antennal arista short or long-plumose; neither sex with distinct orbital bristles. d. No facial carina between the antennæ. RHYNCHOMYIINÆ e. Arista short-plumose. _R. speciosa._ Europe. _Rhynchomyia_ R. D. ee. Arista long-plumose. _I. phasina_. Europe and Egypt. _Idiopsis_. B. B. dd. With flattened carina, the bases of the antennæ separated; no abdominal macrochætæ. COSMININÆ _C. fuscipennis_. South Africa. _Cosmina_ cc. Antennal arista pectinate; bases of the antennæ separated by a flattened carina. RHINIINÆ R. D. d. Cell R_5 open, or closed at the margin. e. Third segment of the antenna twice as long as the second; claws of both sexes short; cell R_5 open. _I. lunata._ Eastern Hemisphere. _Idia_ Meigen ee. Third segment of the antenna three times as long as the second; cell R_5 open or closed; claws of the male long and slender, of the female shorter than the last tarsal joint. _I. mandarina_, China. _Idiella_ B. B. dd. Cell R_5 petiolate. _Rhinia_; and _Beccarimyia_ Rdi. bb. Proboscis long, directed forward, adapted for piercing. STOMOXINÆ c. Arista flat, pectinate above with plumose rays; sternopleurals 1:2; bases of the veins R_1 and R_{4+5} without setæ; base of the media bowed down; apical cell opens before the apex of the wing. African species. GLOSSINA Wied. d. Species measuring over twelve mm. in length. _G. longipennis_ and FUSCA. dd. Species less than twelve mm. in length. e. All segments of the hind tarsi black. f. The fourth and fifth segments of the fore tarsi black; antennæ black (fig. 164). G. PALPALIS R. D. ff. Otherwise marked. _G. bocagei_, _tachinoides_, _pallicera_. ee. First three segments of the hind tarsi are yellow, the fourth and fifth segments are black.