630 MR. F. E. BEDDARD ON 



contact not uniting, thus leaving a slit-like orifice, which is dimly 

 seen when the scolex is viewed in its entirety. 



The general aspect of the body is like that of other Tapeworms, 

 in that the anterior region is much narrower than the posterior 

 region, where the segments are in every way larger. In the 

 present worm this distinction is very marked, and the posterior 

 segments are rather more than oval in section, and approach 

 a cii'cular contour. At the same time, this region of the body is 

 much stronger and thicker in every way than the anterior region, 

 so that there is a tendency for this part to become bi-oken oflf. 

 There seems to be a rather sudden transition between the anterior 

 and the posterior regions. The posterior region of the body, in 

 fact, has quite the contour of an Earthworm, and entirely lacks the 

 flattened appeaiance of a typical Oestode. The cause of this 

 differentiation is doubtless to be sought in the swelling caused by 

 the dissemination of the ripe eggs through the medullary layer. 

 It is, in fact, in the posterior region that the uteri of the pro- 

 glottides have entirely disappeared, and ai-e replaced by eggs 

 scattered singly through the parenchyma of the middle layer of 

 the body. 



This state of afiairs was, however, only to be noted as existing 

 in a marked fashion in the larger and, therefoi'e, presumably more 

 fully mature examples of the worms. Fresh specimens reached 

 about 60 mm. in length, though in none did the breadth of the 

 body exceed 2 mm. Indeed, 1-1 -5 was the prevalent diameter. 

 In smaller worms of 30-40 mm. length, the posterior pro- 

 glottides were by no means so swollen and remained comparatively 

 flat. So far as can be seen from an examination of the dozen or 

 so of specimens of this worm which I have in my possession, there 

 is no detaching of proglottides. In the first place, I always found 

 the terminal proglottid in its place, and to be distinguished from 

 the others by its oval posterior boundary interrupted by a large 

 orifice (apparently of the water vascular canals) highly suggestive 

 of a proctodoeal invagination. 



Secondly, the posterior set of segments were not materially 

 difierent in their form from those preceding them. In those cases 

 where proglottides are shed singly, it is common for them to 

 assume an oval form at the end of the body, and at least to be 

 a good deal constricted at their junctions with each other. There 

 is, commonly, also a very considerable increase of length of the 

 individual proglottides, which favours an easy rupture of their 

 connection. In none of these features do the terminal proglottides 

 of this Oochoristica agree with those of the genera which con- 

 stantly shed their proglottides singly. Indeed, I have observed 

 that the five or six terminal proglottides are occasionally even 

 shorter than those which immediately lie in front of them. These 

 facts, coupled with the absence of a " neck " where new proglottides 

 are formed, incline one to the belief that the growth of a scolex 

 is limited, and that the whole posterior region dies and liberates 

 the eggs. But of this I have no direct evidence. The relative 



