Internal Parasites of the Tweed Salmon. 



117 



specimens aji^reed better with tlie description of the latter. 

 Found occasionally in smolts and once in a small salmon. 

 Leno-th 7-9 mm. A freshwater form. 



Bothriocephalus infundibulifornxis, Rud. Eatoz. t. ii. i. p. 46. 



Same as B. prohoscideus, Rud. This tapeworm, which 

 lias a wide distribution among marine fishes, is in appearance 

 the most formidable parasite of the Tweed salmon. It does 

 not seem to be seriously harmful to its host, and is to be 

 found in the largest and best-fed fishes, usually in numbers 

 ranging from 1 to half a dozen. The great infections of 

 from 100 upwards mentioned by Zschokke as occurring in 

 the Rhine salmon have not been observed in the case of the 

 Tweed fishes, but have been noted in the sea-trout of the 

 same river. In one sea-trout as many as 150 specimens, all 

 very young, were counted. The head of the tapeworm is 

 almost invariably attached near the bottom of a pyloric 

 caecum. 



Appended is a table giving the occurrence of this tapeworm 

 as noted in the fishes observed at the Berwick-on-Tweed 

 Salmon Company's Fish House in 1895 : — 



