This group comprises a number of small flies which have the head furnished with a fleshy proboscis; the slender antennae adorned with fine hairs, thickest upon the male; and the ocelli wanting. Their wings are usually narrow; and many of the large species have the general appearance of mosquitoes. The members of this family are very extensive and world-wide in their range; the larvae of the typical Genus _Chironomus_ live chiefly in stagnant water. They sometimes swarm in such numbers in the North American lakes that they form the chief food of the fresh-water fish. In England on account of their colour they are known as “blood-worms.” Some species live in salt water, and others breed in excrement and dung. The perfect insects are easily collected with a sweeping net in the vicinity of swamps and watercourses. Skuse has described 64 species from Australia (Pro. Linn. Soc. N.S.W. 1889), previous to which only 8 species, described by Messrs. Walker and Macquart, had been recorded. The family is divided into a number of genera, of which _Chironomus_ includes 21 species of the more typical slender-bodied midges, and the Genus _Ceratopogon_ 17 species of our vicious “Sand-flies.” These pests are also found in Great Britain and in North America, ranging as far south as Chili. _Ceratopogon molestes_, described by Skuse, is our common “Sand-fly,” though there are others probably quite as annoying if not so abundant. It is a tiny little dark coloured midge, so quiet and small that it is usually felt before it is seen. There is another very large grey “Sand-fly” I have met with in the interior of N.S. Wales on the Darling River that frequents grassy watercourses and flies straight at the hands or face like a wasp. It has been reported from Central Queensland that after the great flood and abundant growth of grass (1905) the sand-flies increased in such numbers, that they caused the blindness and death of a great number of marsupials, through biting them in the eyes. Family 5. Crane-flies. TIPULIDAE.