Alliance 2. Acalyptera. Proboscis having thick lips, and retractile into a large cephalic cavity; alulæ or halteral opercula arrested—Hypocera to Dolichocera.
Alliance 3. Dung-flies. Characters similar to the above, but the alulets are of considerable size—Muscidæ.
Fam. 2. Hymenopteroid Diptera, Dasseln.
Antennæ as in preceding family, but the bisetaceous proboscis is thin and horny, with small labia, or else large labia with four setæ—Œstridæ, Conopidæ, and Syrphidæ.
Alliance 4. Parasitic Diptera. Two setæ with or without a lipless proboscis—Œstridæ, Myopariæ, and Conopidæ.
Alliance 5. Syrphidæ. Four setæ within a similar kind of proboscis; the third joint of the antennæ spatulate; the palpi thickened.
Alliance 6. Leptidæ. Four setæ within a short thick-lipped proboscis, the third antennal joint mostly coniform—Therexidæ, Leptidæ, and Dolichopidæ.
Fam. 3. Lepidopteroid Diptera, Gölsen.
Antennæ multiarticulate and stipiform; proboscis with and without labia, mostly four and six setæ for punctuation—Tipulidæ, Tanystomidæ, Stratiomydæ, Tabanidæ.
Alliance 7. Gnats. Antennæ filamentary and multi-articular. Proboscis varied.