A NEW SPECIES OF TAPEWORM. 



399 



they were taken, and I had been asked to give a decisive opinion 

 as to what species of tapeworm they belonged to, I should have 

 said emphatically, from my previous knowledge, and being as 

 I am in possession of that particular worm as a type-specimen, 

 that they were the hooks from the rostellum of Taenia anatina, 

 parasitic in Anas boschas fera and dom. Indeed, only the fact of 

 seeing the hooks on the rostellum and scolex of the original worm 

 from which they were taken would have convinced me otherwise. 

 This will serve as an admirable illustration of the point I raised 

 in a paper read before the Quekett Club last October as to the 

 internal anatomy of the worm being a most important factor 

 generically, and as to the insufficiency of the formulae propounded 

 by Professor Raillett for determining the genus by the shape of 

 the hooks, important as they necessarily are as an aid to specific 

 identification 



Table of Differences. 



