308 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



caution can hardly be exercised. In this specimen the 

 bothria are placed on short but distinct pedicels round 

 a large dome-shaped myzorhynchus. On looking down 

 on the latter structure from above, the insertion of the 

 bothria is well seen. The outlines of the latter structures 

 are fairly simple. Each is bounded by a raised rim or 

 border, which is most prominent on the anterior margins. 

 This rim is very slightly cut into or folded. The bothria 

 are set exactly opposite to each other. On the anterior 

 margin of each, and, as seen from above, apparently lying 

 on the myzorhynchus, is a large accessory sucker, or 

 acetabulum. Anteriorly this acetabulum has a thickened 

 rim : posteriorly this rim appears to be much thinner. 



The single specimen obtained by me is a very young 

 one, and it apparently possesses a distinct neck, thus 

 differing in what appears to be an essential feature from 

 the worm described by Linton. But the age of the 

 specimen probably accounts for this difference. Linton's 

 1 fig. 17 represents a young stage of Crossobothrium 

 laciniatum, and in this specimen there is a distinct neck : 

 that is, segmentation does not begin immediately behind 

 the head as in mature worms, but at some little distance 

 posteriorly. 



I conclude then that this specimen is probably 

 Linton's species, but may possibly be only a young stage 

 of Phylloloihrium thvidax, in which the preservation has 

 influenced the form of the bothria so as to give the worm 

 an appearance different from the typical one. 

 The measurements are : — 



Diameter of head : 0'79 mm. ; 



Greatest width of strobila : 019 mm. ; 



Length of strobila : 8 mm. ; 



Greatest diameter of accessory suckers : 0*13 mm, 



