218 Transactions. — Zoology. 



species of each of the famihes. These diagrams have in every 

 case been drawn from living specimens. All the material that 

 I at present possess has been collected by myself, chiefly in 

 the neighbourhood of Lincoln College; but during the summer 

 vacation many specimens have been collected in various widely- 

 separated parts of the colony. I have not thought it advisable 

 to arrange keys for reference until so many specimens have 

 been collected that they may be considered to form a fair per- 

 centage of the total number of species in the colony. 



In regard to collecting specimens, I have, like Mr. Skuse, 

 found that glass tubes are the most suitable apparatus. Some 

 bruised laurel-leaves should be placed in the bottom of the 

 tube, and over these a layer of blotting-paper. This will 

 absorb the moisture given off by the laurel-leaves, and there- 

 fore protect the insects from the injury that always results to 

 them from contact with fluid. Most of the smaller and many 

 of the larger species can be collected by placing the tubes over 

 them with care whilst they are settled on some object. They 

 will usually not rise until the tube completely covers them, and 

 after a little fluttering about they will die. Specimens cap- 

 tured in this way should be fixed as soon as possible with gum 

 on thin white cardboard. Gum of tragacanth, with a trace of 

 corrosive sublimate, is the most suitable substance, as it does 

 not cause any glaze on the surface of the cardboard. Only a 

 very small spot of gum is necessary, and the legs and wings 

 should be spread out as nmch as possible, but not at the risk 

 of mutilating the specimen. The larger and more active in- 

 sects can be easily caught with a gauze or muslin net of the 

 ordinary make, but the net should not have a ring of too large 

 diameter, otherwise it will be found exceedingly cumbrous in 

 bush districts, where most of the Diptera Nemocera are found. 

 I have collected large numbers of specimens from windows 

 looking out on to shady and moist gardens. If the top is left 

 slightly open it will be found that many insects enter and 

 flutter about on the glass-panes, where they are very easily 

 captured. I shall be very happy to supply glass tubes and 

 other requisites to any one who will be good enough to catch 

 a few of these insects for me. 



The only literature I have been able to obtain on the 

 Diptera are Walker's " Insecta Diptera Biitannica," Theo- 

 bald's "Account of British Flies," Hutton's "Catalogue of 

 New Zealand Diptera," some of Osten-Sacken and Loew's 

 " Monographs of the Diptera of North America," and Mr. 

 Skuse's admirable " Monographs of the Australian Diptera." 

 These last so ably summarise the work of the best-known 

 American and European authors on the Diptera that I shall 

 in every case adopt the classification employed in them, and 

 thus render the New Zealand Diptera very easily comparable 



