46 EXPERIMENTS WITH CERTAIN DIPTERA. 



Among the reptiles the " goanna " Varanus varius is 

 commonly infested \Wth a large filaria, but the embryos 

 have not been found in the Ijlood stream. The jew lizard, 

 Amphibolurus barbatus, harbours a small filaria, the embryos 

 of which occur abundantly in the blood of some indi\ iduals. 

 It has been proved, however, by Dr. T. L. Bancroft, that 

 Gulex fatigans, the common house mosquito, can act as a 

 host for this latter filaria ; consequently its normal host 

 is almost certain to be one of the native mosquitoes. The 

 water dragon, Physignailms lesueicrii, is parasitised b}' 

 F. physignathi Johnston. 



It had been intended during the latter months of 19 K> 

 to try to infect Tabanids by feeding them on the infected 

 blood of several of the commoner species of birds and on 

 the fluid surrounding the knee joints of kangaroos paras- 

 itised by F. websteri, but the extreme scarcity of the flies 

 prevented the work from being proceeded with. This 

 seasonal scarcity of Tabanids has been recently referred to 

 by Ferguson and Henry (P.L.S., N.S.W., 1919, p. 829). 



Examination of Muscids, etc. 

 Examination of wild flies of the species M. fergusoni 

 Jnstn. and Bancr., M. vetustissima Walker, M. ferroe- 

 regince Jnstn. and Bancr., and the little black Fannia 

 Homalomyia sp., all, with the exception of M. terrce-reginoe 

 Jnstn. and Bancr., common on stock at certain times 

 in the year, revealed the fact that local flies are parasitised 

 by four distinct kinds of nematodes, namely : Habronema 

 muscce, H. megastoma, Agamospirura muscariim and 

 Agamonema fannice. 21. fergusoni and M. vetustisshna 

 harbour all four kinds ; M. ferice-regincs only the first 

 three as far as is known ; and the Fannia only the last named. 



M. fergusoni. 



Total number of flies examined . . 

 Number infected with Habronema spp. . . 

 Number infected with Agamospirura muscarum 

 Number infected with Agamonema fannice 



M. vetustissima. 



Total number of flies examined 

 Number infected with Habronema spp. 

 Number infected with Agamospirura muscarum 

 Number infected with Agamonema fannioe 



