240 



Onchocerca lienalis, Stiles, 1892. 

 Figs. 2, 6, 8, 11, 14, 17, 27. 



In the former account (Johnston and Bancroft, 1920) 

 mention was made that "0. bovis" was to be met with in 

 Queensland cattle in the gastro-splenic ligament, and it was 

 suggested that the species was probably identical with 

 Piettre's. Recent examination shows them to be quite 

 distinct. 



0. lienalis is extremely common in cattle in this State, 

 especially in dairying districts in the south-eastern portion of 

 it. It has been stated to me that nearly 100 per cent, of 

 cows and bulls and perhaps 50 per cent, of oxen slaughtered 

 are found to harbour this parasite whose presence in Aus- 

 tralia had not previously been noted. In the Rockhampton 

 district the worm is very common, but apparently less so 

 than in the south-eastern part of the State. Mr. N. V. Brown 

 has informed me that it is commonly met with in cattle in 

 New South Wales. 



The female nematode is readily overlooked owing to its 

 location in the connective tissue, between the stomach and 

 the spleen, especially adjacent to the latter, where the tunnel 

 enclosing the parasite, if noticed, would easily be mistaken 

 for an empty blood-vessel. The organism lives in a very 

 delicate worm-like fibrous tunnel in the connective tissue, 

 this tunnel showing no tendency to become thickened except 

 occasionally at the tail end of the worm. There is then 

 comparatively little fibrosis and no typical nodule formation 

 as the parasite does not roll itself up in the tissues, except 

 sometimes at the extreme posterior end, where coiling may 

 occur and a slight local thickening of the tissue become 

 noticeable. A female specimen, measured in situ, reached 

 316 mm., while another (also in situ), whose extreme anterior 

 end was missing, was 425 mm. long, its estimated length 

 being 460 mm. Usually only two or three worms seem to 

 occur in each host. Though every female examined (from 

 about 25 different hosts) contained uterine larvae, in only 

 one case was a male obtained. 



As the worm has never been described, it seems advisable 

 to place on record some data regarding it. Stiles named it 

 Filaria lienalis, in 1892, from cattle in United States of 

 America, but the description was lost during transit. In 

 1894 he referred to the parasite as Spiroptera reticulata. 

 Both Leiper and Gedoelst, in 1911, placed it under Oncho- 

 cerca. 



Description of the Female. 



The anterior end of the female is extremely delicate 

 (figs. 6, 17) and it is a matter of chance whether one succeeds 



