BY T. HARVEY JOHNSTON, M.A, D.SC. 223 



imakes suggestions regarding the probable life-history, 

 these having been referred to earlier. In regard to the 

 geographical distribution, he refers (p. 10) to an encysted 

 parasite found by Stiles in 1892 in cattle in the United 

 States, and mentioned under the name Filaria lienalis. 

 Stiles. A description was not published,* and at a later 

 date (1894), this nematode was regarded as being 

 " Spiroptera reticulata.'' There is, therefore, little doubt, 

 but that the parasite in question is an Onchocerca, perhaps 

 identical with 0. gihsoni, but I am inclined to believe that 

 it will be found to be a different species, whose normal 

 or original host may have been the bison. Some support 

 for the idea that the two forms may be distinct is derived 

 from the fact that Algerian oxen harbour a different species, 

 O. gutturosa, Neumann, and that Indian and East Indian 

 cattle may be parasitised apparently by two species, viz., 

 O. gihsoni and 0. armillata. Ford (lG03)t met with one 

 kind — " the aortic worms " — which form nodules in the 



. aortic walls of Malayan buffaloes. These are regarded 

 by Leiper (1911, a, p. 10), as belonging to 0. gihsoni, while 

 Railiiet and Henry (1910) describe the aortic worms which 

 infest oxen and buffaloes in India and Sumatra as a distinct 

 form, which they named 0. armillata. If these species be 

 identical, then the latter will rank as a synonym of 0. 

 gihsoni, only a few weeks separating their respective dates 

 of publication. They appear to me to be specifically 

 distinct. Tuck (1907, 1908) referred to the aortic worms 

 as well as to another kind — also belonging to the Filariidae — 

 from Indian and Siamese bullocks. From the accounts 



given, we had regarded both of these as being distinct from 

 0. gihsoni. It seems probable that the '' aortic worms " 

 (which are not yet recorded from Australia) are 0. armillata, 



. and that the ordinary " nodule worms " from the brisket 

 and flank are 0. gihsoni. As already mentioned, 0. 

 gutturosa is usually restricted to the cervical ligament. 



* In Stiles and Hassall's Index Catalogue of Medical and Veterinary 



Zoology, part 29, 1910, p. 2266, there is a reference to a paper by Stiles 



[1892, q] " On the presence of Spiroptera reticulata in cattle," but mention 



is made that the MS. was lost in the mail. The paper is, therefore, 



unpublished. 



I Lingard (1905) recorded their presence in Indian cattle. 



