270 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



INTERNAL PARASITES AND DISEASED 

 CONDITIONS OF FISHES. 



By Jas. Johnstone. 



1. CESTODA. 



2. TREMATODA. 



3. PROTOZOA. 



4. CATARRHAL CONDITIONS IN DAB 



AND SALMON PARR. 



L— CESTODA. 

 Abothrium rugosum (Goeze). 



From Gadus callarias. This is Bothrioce / phalus 

 vugosus (Goeze) Rudolphi = van Beneden's Abothrium 

 gadi. 



About a dozen large cod were dissected last winter, 

 and this cestode was invariably found. Sometimes there 

 were as many as a dozen large worms in each fish. The 

 head of each cestode is implanted in a pyloric caecum, in 

 such a manner that it is impossible to extricate it. I 

 repeatedly dissected these structures with the greatest 

 care, but was never able to find anything resembling a 

 typical bo'thriocephalme scolex and I do not think that 

 this structure exists in the mature stages of the worm. A 

 portion of the anterior end of the strobila is buried up in 

 a caecum and when the walls of the latter are picked 

 away bit by bit with dissecting needles all that remains 

 is a contorted, horny or waxy-looking, thick filament. 

 The walls of the caecum undergo profound change and 

 become semi-transparent and waxy, sometimes horny, in 

 nature. Sometimes the anterior end of the cestode has 

 perforated the lateral wall of the caecum and lies outside 

 the latter as a contorted kind of cord. It is possible to 

 pick away this investment and then the greatly con- 



