"200 RECORDS OF THE AUSTRALIAN Ml]SEUM. 



Notes. — About the middle of November, 1917, in a valley at Duualiey, 

 Tasmania, I noticed the g-limmer of a male specimen in a ciack of a very 

 much chai-red dead tree, from which after diligent search another specimen 

 was taken. In the same locality a day later my wife took a series 

 containing both sexes from the under side of a fallen tree lying well above 

 the ground. Other specimens have been taken in widely separated places 

 prior to this, but invariably there were males only. 



A carious phenomenon that has excited the interest of most collectors 

 in Tasmania is to be found in the sudden disappearance of the male of 

 this fly when in flight. A specimen may be seen approaching as a silvery 

 white spot, which suddenly disappears. This apparition may be observed 

 several times a day, and only with difficulty can it be netted. Now if the 

 insect be slowly turned round it will be noticed that when seen from the 

 front the other colours ai-e completely obliterated by a silver^^ sheen, but 

 viewed from the sides or rear the thorax is black and the abdomen is 

 bi"own with a dai"k central stripe. It is evident, therefore, that the silvery 

 spot approaching is the insect advancing with the head towards the 

 observer, and a more conspicious insect is not to be seen in the bush, but 

 immediately the insect turns the silver colour is lost, and the fly becomes 

 invisible to the e3-e, which cannot follow the rapid change in colour. 



