86 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



seen that the terminal os in the myzorhynchus leads into a 

 kind of atrium in which there is a proboscis. The latter is 

 bowl-shaped, presenting very much the same appearance 

 as the large ventral sucker in a Trematode. Its internal 

 walls are not smooth, but are thrown into lobes by the 

 contraction of the intrinsic and extrinsic musculature of 



Fig. 5, Echeiieibothriiim variabile. van Beneden ; the upper figure is a 

 z general view of the scolex, the lower figure represents another 

 scolex prepared to show the internal proboscis, 



the structure. The wall of the myzorhynchus immediately 

 round the os is strongly muscular, so much so llial we may 

 speak of the presence of a distinct sphincter ; and there are 

 also longitudinal muscle fibres passing back to their origins 



