INTRODUCTION. 



These catalogues are chiefly compilationsj and should not have 

 been thought worthy of publication if it were not for the great diffi- 

 culty there is, in the colony, in obtaining descriptions of many of our 

 animals which have been published in expensive books, or in still 

 more expensive periodicals. I have to thank Mr. A. G. Butler, of the 

 British Museum, for sending me copies of descriptions of two genera 

 and three species which were not to be obtained in the colony ; and 

 to Mr. Max Mendershausen, for translating the descriptions of the 

 New Zealand Diptera in the Reise der Novara. 



My principal difficulty with respect to the Diptera has been in 

 trying to assimilate the nomenclature of the various authors, espe- 

 cially with regard to the veins and cells of the wing. As there is 

 still some ambiguity about these points, I cannot do better than give 

 Dr. Schiner's description of his system,^ which seems to me the 

 most simple, and which I have adopted in this catalogue; and also 

 add a table showing the relations of this system with those of Mac- 

 quart and Loew : — 



" In a few cases three, but in most cases only two, longitudinal 

 veins spring from the base of the wing, and these by their division 

 give rise to the other longitudinal veins. The third of these veins, 

 when present, is very small. The others are called the upper and loiver 

 primary veins. They are always united by a transverse vein, which is 

 usually perpendicular to the long axis of the wing, but is sometimes 

 oblique and curved, and then not easily distinguishable. The outer 

 margin of the wing is occupied by the costal vein ; the upper primary 

 vein may be called the subcostal. From the subcostal vein springs 

 the second, and from this the third longitudinal, or the radial and 

 cubital veins. When only a single inferior branch is emitted by the 

 subcostal vein, it is to be regarded as the cubital. Between the sub- 

 costal and the costal there is another longitudinal vein, the mediastinal, 

 which however is frequently amalgamated with the subcostal. The 

 further divisions of the radial and cubital veins, when such exist, do 

 not require special names. 



" The lower primary vein is the postical ; it emits a branch above 

 and below : the upper branch is the discoidal, the lower the anal 



* Translated by W. S. Dallas, Esq., F.Ii.S., M.E.S., Zoological Eecord, 1864, p. 533. 



