[Read before the Otago Institute, 8th June, 1909.]

This papaer is composed from the notes on the Diptera which I have collected in Otago during the last two seasons.^* The species dealt with are to be found described in the “Synopsis of the Diptera Brachycera of New Zealand” (Trans. N.Z. Inst., vol. xxxiii), by the late Captain Hutton; those described elsewhere have the references attached. Only a few of the more common species are figured in colour in this paper, as diagrams and coloured plates of all the species will appear later in a series of papers which I hope to publish, dealing with both new species and those flies already described by Captain Hutton. Where it is deemed necessary, I insert a brief account of the general characters and habits of the families.

I am indebted to Professor Benham for his invaluable suggestions during the preparation of this paper.

To avoid repetition I shall here give a description of the general features of the localities mentioned:—

Ocean Beach forms the ocean side of the isthmus connecting Otago Peninsula with the mainland. This isthmus, which is about a mile in width, is formed, for the most part, of blown sand and alluvium, and is bounded on the opposite side to the beach by the mud-flats at the head of Otago Harbour. The sandhills of Ocean Beach are covered with lupinbushes and marram-grass.

Tomahawk is separated from Ocean Beach by Lawyer's Head. Behind the sandhills of Tomahawk is a lagoon into which run the streams from the surrounding hills; the overflow finds a course over the sand to the sea. Lupin-bushes and marram-grass abound.

Purakanui is the district to the north of Otago Heads. The coastline of this locality is formed of a series of precipitous headlands with intervening sandy beaches, behind each of which there generally exists a mud-flat or swamp fed by streams originating from the hills. Of these, Murdering Beach is a short strip of sand, surrounded by steep hills, and backed by a swamp in which rushes and other forms of vegetation grow. Long Beach is a stretch of sand of considerable length, and an extensive area of cultivated land (often under water) exists behind the sandhills. Mapotaki Beach faces the north (the last two face the north-east), and is somewhat similar in form to the preceding, differing in the fact that the sea gains an entrance to the mud-flat by a small stream which runs across the beach after draining the swamp. The surrounding hills of Purakanui are in places covered with what remains of the native vegetation.

Mount Cargill (2,232 ft.) is situated toward the north of Dunedin, and is still more or less covered by the native bush, which is either being felled or burned off.