78 



DR. F. E. BEDDARD ON THE 



a greater distinctness in D. expansa. This is also due to the fact 

 that in the last-mentioned species the axis of the scolex is formed 

 from the medulla only (text-fig. 3. a), while in J), fimbriata the 

 axis is apparently formed from both medulla and cortical layer. 

 The point of difference is further emphasised by the more modified 



Text-figure 3. 



Longitudinal section through scolex of Duthiersia expansa. 



a, axis of scolex continuous with medulla only of strobila region (m) ; c, cavity 

 of hothrial groove displayed here and there ; o posterior orifice of this 

 cavity. 



structure of the axis in D. expansa, where it presents the appear- 

 ance of a more clearly defined network, the spaces being largely 

 quadrilateral in outline. There is not this plain histological 



