BY T. HARVEY JOHNSTON, M.A., D.SC. 21B 



Shipley * (1910), and Hancock (1911, p. 25) refer to it 

 under that name ; Leiper* (1910), as Onchocerca reticulata ; 

 Bancroft (1893), as Strongylurus sp. ; CI eland (1907, p. 88), 

 and Johnston (1909, p. 412), as Spiroptera sp. ; and Try on 

 "(1910, p. 81), as Spiroptera [Onchocerca) sp. ; while Cleland 

 and Johnston, a little later (1910, a, p. 174) described it 

 as a new species of Filaria, F. gihsoni. Later in the same 

 year (1910, c, p. 96), they removed it to the genus Onchocerca, 

 Later authors (Leiper, 1911 ; Nicoll, 1911 ; Gilruth and 

 Sweet, 1911), have followed them in calling it 0, gihsoni. 

 The synonymy of the nematode may be summarised thus : — 

 Onchocerca gihsoni (C. and J., 1910, a), Cleland and 



Johnston (1091, c). 

 ? Filaria lienalis, Stiles, 1892 (undescribed). 

 Spiroptera reticulata, Park, 1893, Bernard and Park, 

 1893 ; Shipley, 1910, etc. (/lec, Diesing, 1841). 

 Strongylurus sp., Bancroft, 1893. 

 Spiroptera sp., Cleland, 1£07, Johnston, li>09. 

 Filaria gihsoni, Cleland and Johnston, 1910 a. 

 Spiroptera {Onchocerca) sp., Tryon, 1910. 

 Onchocerca reticulata, Leiper, 1910 [nee. Diesing). 

 Filaria [Onchocerca) gihsoni, CI el. and Johnston, 1910, d. 

 Onchocerca gihsoni, CI el. and Johnston, 1910, c ; Leiper, 

 1911, etc. 

 Onchocerca reticulata, Diesing, known more commonly 

 but less correctly, as Spiroptera reticulata, is a distinct, 

 but closely allied, parasite infesting the horse, and is 

 known under various synonyms, e.g. : Filari reticulata, 

 F. cincinnata and Spiroptera cincinnata. F. lienalis. Stiles, 

 may be a synonym of 0. gihsoni, and is evidently an Oncho- 

 cerca, as Leiper (1911, a, p. 10) has suggested. Its specific 

 identity with the Australian worm seems to me to be unlikely. 

 The main distinctions between 0. gihsoni and 0. reticulata 

 have been tabulated by Leiper (1911, a; p. 10). 



The original account (1910, a) contains a few in- 

 accuracies regarding the male worm, but these were corrected 

 and a more detailed description of the male, female and 

 embyro was given in a larger report published some months 

 later. (August, 1910, c.) Gilruth and Sweet have shown 

 recently (1911), that there is a considerable amount of 



* Quoted in an abstract of a report (1910) — Editor Jour. Meat and 

 Milk Hygiene, 1911, p. 24. 



