236 E. W. FERGUSON. 



in the inland parts than on the coast; it is also almost, if 

 not entirely, confined to the summer months. Spaniopsis 

 on the other hand is, so far as known, a coastal and moun- 

 tain genus, and also seems to appear during the winter 

 months. I have reason to think, however, that Bung Eye 

 is probably more prevalent in the neighbourhood of Sydney 

 than is generally thought. Over sixty cases occurred 

 among the patients at Rydalmere Hospital for the Insane 

 during three months in the beginning of the summer of 

 1912-13. I have also been informed that Bung Eye was 

 exceedingly common among the men engaged in building 

 the dam on the Hawkesbury River, on the mainland opposite 

 Milson Island, in a locality where these flies have been 

 taken on several occasions. Bung Eye also occurs at 

 Mount Irvine in the Mount Wilson district, a locality 

 whence these flies have been obtained. 



The four species now to be described are all closely allied 

 inter se and to S. tabaniformis, but can readily be dis- 

 tinguished by difference in size, length of arista and colour- 

 ation of legs and of the ventral surface. They all exhibit 

 the generic characters described by White in the antennae 

 and wing venation. 



The term arista applied to the process of the third 

 antennal joint seems to my mind somewhat misleading; it 

 is rather a prolongation of the third joint itself. Its length 

 varies in different species and reaches its greatest develop- 

 ment in S. longicornis. In S. vexans and S. rnarginipennis, 

 the discal cell varies in different specimens or on the two 

 wings of the same specimen; in some there is a distinct 

 angulation below, in others this is rounded off; in some the 

 third veinlet is present as a very short stump, in others it 

 is absent and the angulation from which it arises is rounded 

 off. The minute veinlet inside the cell at the lower angu- 

 lation described by White, was also noted in some of my 



