VAN BENEDEN'S CLASSIFICATION OF THE CESTODES. 



389 



The Tceniadce are characterised by the want of a special uterine 

 opening, and more especially by the possession of four simple 

 suckers, between which on the apex there is usually one complete 

 circle of hooks, but sometimes more. 



FIG. 226. 



Tetrarhynchus 



sepice 

 (isolated head). 



(x 12.) 



L 



Bothriocephalus latus 



(cephalic end). 



(x8.) 



Tcenia 



echinococcus. 



(x 10.) 



Eckineibotlirium minimum 

 (after van Beneden). ( x 8.) 



In the BothriocepJialidce the attaching apparatus is reduced to two 

 longitudinal grooves, which have only a slight mobility, and some- 

 times become so shallow that they can hardly be regarded as inde- 

 pendent structures. Only in a few cases do we find hooks at the 

 anterior end. The segmentation is often indistinct, and sometimes 

 wholly disappears, so that the whole body forms one united mass. 



Man is infested by various species of Cestodes belonging to the two 

 families of the Tseniadse and Bothriocephalidse. The majority belong to 

 the former of these families, which is indeed most widely distributed 

 among terrestrial animals. The human Taenioid parasites in the adult 

 stage are Tcenia saginata (T. mediocanellatct), T. solium, T. cucumerina, 

 T. nana, T. flavomaculata, and T. madagascariensis, 1 - some of which, 



1 According to Heller (" Darmschmarotzer," in Ziemssen's " Handbuch d. spec. Pathol. 

 u. Therapie," Bd. vii., 2, p. 560), there is in the Pathological Institute at Erlangen 

 another still undetermined Tcenia, which was voided by a child. 



