54 NE IV ZEALAND ENTOMOLOGY. 



merits, which arise from the top of the thorax and serve 

 the purpose of gills (Fig. lb). Before emergence the 

 anterior segments are projected nearly out of the cocoon 

 from which the perfect sandfly makes its escape, and float- 

 ing to the surface of the water ascends the stem of an 

 aquatic plant to expand its wings. I should here remark 

 that as with the mosquitoes, the bloodthirsty propensities of 

 the present species have no doubt been acquired since the 

 arrival of man and other warm-blooded animals. 



Group BRACHOCERA. 



Family Tabanid.-e. 



Tabanus impar (Plate VI., fig. 6). 



I have figured this fine species as a representative of a 



most important family of Dipterous insects, but am at 



present quite unacquainted with its life-history. It occurs 



plentifully on the margins of the forest throughout the 



summer. 



Family BOMBYLID.E. 



Comptosia bicolor (Plate VI., fig. 2). 



This conspicuous species is very abundant in glades- 

 throughout the summer, flying with great rapidity, and 

 delighting to suck honey from the numerous shrubs which 

 are in blossom at that time of year. It is a social species, 

 and is usually found in companies of fifteen or twenty 

 individuals, which engage in endless dances, two insects 

 often seizing one another on the wing and then re- 

 volving together like a wheel in rapid motion. Their 

 manoeuvres in avoiding the strong gusty wind, so often 

 prevalent in earl}- summer, are also interesting ; the insects 

 play upon the wing whilst the air is quiet, but if a breeze 

 springs up they instantly settle on the nearest bush, rising 

 to renew their sports when it is again calm. These flies are 

 rather variable in colour, some specimens being dark brown > 



