244 



DE, F. E. BEDDARD ON 



minute structure of this apical organ seems to indicate that it is 

 to be i-egarded rather as a sucker than a rostellum. The apical 

 organ of Acanthotcenia*, on the other hand, is, as I think, of the 

 nature of the rostellum of other tapeworms. 



Text-fig. 45. 



Transverse section through scolex of SolenotcBnia viperis. 



S. One of four large suckers, s. Small apical sucker showing its minute 

 size in comparison with large suckers. 



The accompanying figure (text-fig. 46) shows several out of 

 a series of transverse, slightly oblique, sections through this 

 apical sucker. Being rather oblique they show the external 

 surface, which is slightly concave. The nuclei, which are chiefly 

 towards the external surface of the sucker, seem to me to be 

 rather larger than those in the four lateral suckers. Previous 

 investigations upon this apical structure are not entirely con- 

 clusive. Riggenbach f finds an apical depression in Ichthyotcenia 



* P. Z. S. 1913, p. 8, text-fig. 1, R. 



f "Das Genus Ichthyotania," Kev. Suisse Zool. iv. 1897, p. 165. 



