BY T. HARVEY JOHNSTON AND M. J. BANCROFT. 41 



We are of opinion that the Onchocerca worm^s (male 

 and female) which Cleland found in a loose coil near the 

 hip joint of an ox in N.S. Wales (1914, p. 47 ; 1914, p.p. 

 137, 150), belonged not to 0. gibsoni, but to the same 

 species as that which we now identify as 0. bovis. 

 The situation is one of those mentioned by Piettre (1916), 

 in which 0. bovis may be met with. 



Examination or Captured Flies for the Presenck 

 OF Parasites. 

 We deem it of interest to give an account of the various 

 parasites found in flies during our examinations. The 

 species of Habronema, H. muscce, H. megastoma and H. 

 microstoma are omitted, since they have been dealt with in 

 another paper (Johnston and Bancroft, 1920). 



Examination of Tabanid^e. 

 Tabanus circumdatus was found to be infected with 

 one species of microfilariae. The total number of flie& 

 examined and the number infected were as follows : — 



T. circumdatus 

 Nov lOth, 1918, to Jan. lltli, 



1919 



March 25th— April 19th, 1919 

 April-May, 1919 : 



October Uth, 1919-^January 



14th, 1920 



Total for T. circurtvdatus 



T. cyaneus — the blue Tabauid 

 T. dubiosus — -the black Tabanid 

 T. mastersi f Striped \ 

 T. australiciis\Taha,nids J 



Total for all species .. .. 501 ,, 18 ,, or 3.5% 



Extent of infection. In three cases very few larvae^ 

 embryos (1-9) were found, but in all other cases the infec- 

 tion was extremely heavy. In eight instances only young 

 encysted forms were seen, in the remaining 10 cases fully 

 developed larvae were present, small forms occurring also 

 in some of them. In one case where an actual count of 

 the number of embryos was made the fly was found to- 

 contain 234 fully developed and very active worms, 94 being 

 contained in the head and proboscis, 116 in the thorax 

 and 24 in the abdomen. Other instances would probably 

 have yielded still larger figures had time been spent ia 



