92 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



CPIVP w 



lat mechanism is involved in this process; probably 

 the excretory canals, acting as a water vascular system 

 may be instrumental, and the proboscis would then be 

 turned inside out in much the same way as the proboscis 

 of a Tetrarhynchus or Xemertine worm is everted. The 

 longitudinal retractor muscles would then be put on the 

 stretch, and being inserted in bundles, at intervals round 

 the proboscis, they would pull on the latter so as to throw 

 its muscular ring into lobes. This contraction would 

 flatten the myzorhynchus and produce the prominent rim 

 below the lobes. It would also lead to such distortion as 

 would obliterate the usual form of the bothridial pedicels. 

 The contraction of the bothridia themselves would 

 doubtless be correlated with this extensive contraction of 

 the whole scolex. 



The first of these two specimens differs from Echenei- 

 bothrium with regard to the characters of the strobila. 

 Part of this is represented in fig. 9. The neck in this 

 specimen was distinctly bulb-shaped and without segmen- 

 tation. Then follows a region in which the proglottides 

 are of the usual form. But posterior to this they are much 

 longer than they are broad ; a condition very different from 

 that characteristic of E. variabile. The prominent enlarge- 

 ment of the proglottides represented in the figure is no 

 doubt accidental. But the most posterior proglottides again 

 deviate from the typical form. They are very irregular in 

 size and shape and almost every one presents a prominent 

 groove on one of its surfaces, as if the margins of the 

 proglottis had been turned over. The characters of the 

 strobila appear to me to present a greater difficulty in the 

 identification of the cestode as E. variabile, than do those 

 of the scolex. In the meantime, pending the collection of 

 more material, it is ib well to refer them to this species. 



The specimen of E. variabile, the head of which is 



