XX 43. THEREVIDÆ: non-raptorial flies; smaller, shorter, and more feeble than Asilidæ; though differing much in wing-pattern superficially like some Leptidæ or some Empidæ. XXI 44. SCENOPINIDÆ: a very limited family of smallish flies. _Scenopinus fenestralis_, the "window-fly" was formerly thought to breed amidst old carpets and musty neglected clothing, but its larvæ have been found to be therein predaceous devourers of the larvæ of clothes-moths and fleas; larvæ of other species feed on fungi. XXII 38. CYRTIDÆ: quite unlike any of the preceeding or succeeding families; flies with diminutive heads and large rotund abdomens; proboscis very short or obsolete; the larvæ of some are said to be parasitic on spiders. XXIII 45, 49, 66_a_. EMPIDÆ: an extensive family; about 200 species, mostly of small sizes; of slender habit, and of dull colours; there are 30 genera and the characteristics of some are peculiar; the life-history and habits of most are unrecorded; though with bodies of feeble appearance, some have the proboscis well developed and are predaceous on small insects. Amongst the most curious are some species of the genus _Hilara_, of which the males have the first tarsal joint of the fore-leg thickened and flattened; some species of this genus, not very uncommon, fly and float about carrying "veils" or small cob-web-like attachments. XXIV 50, 65. DOLICHOPODIDÆ: long-legged; a large family of 42 genera; some species of medium size but mostly small, amongst which latter bright metallic colours, often golden green, are common. The life-history of only a few is known. XXV 51. LONCHOPTERIDÆ: a few small slender flies with long pointed wings. XXVI 53. PLATYPEZIDÆ: small flies; the peculiar broad flat larvæ of some of the genus _Platypeza_ have been found in fungi. XXVII 58. PIPUNCULIDÆ: small and uncommon flies with abnormally large eyes. XXVIII 59. SYRPHIDÆ: a most interesting group of 51 genera; "hover-flies," and other various, conspicuous, large and medium sized flies (only a few small), very distinctly characterised and differentiated; the wings show the "vena spuria," and the face is without a "frontal suture." The larvæ are very diversified; some are terrestrial, some aquatic, some insectivorous, some parasitic or commensal in the nests of _Hymenoptera_. XXIX 54, 60. CONOPIDÆ: the wings show no "vena spuria"; the known larvæ are parasitic on _Hymenoptera_ and _Orthoptera_. XXX 62. ŒSTRIDÆ: a few very distinct species; proboscis and mouth parts atrophied; very hairy except one very rare; parasites of mammalia. XXXI 72. TACHINIDÆ: 100 genera, more than 250 native species; with great difficulty classed in divisions, which may rank as separate families; stoutness of body and abundance of strong hairs, or rather _bristles_, are so generally apparent that many species may be guessed to belong to this family rather than to the closely related Muscidæ. Many of the larvæ are parasitic on various insects.