40 



ing, in consequence of which Dr. Weinland has sug- 

 gested the name of Tseniarhyncus (zW, a privitive, 

 and QVV%OS, a muzzle). At first this deficiency of the 

 hooks gave rise to the question, whether these might 

 not be T. solium, which had lost their circlet of 

 hooks by old age, &c., instead of a new genus of 

 Helminths. This question has, I think, been suffi- 

 ciently settled by the experiments of Leuckart and 

 Mosler in Germany, and Simonds and Cobbold in 

 England, with the scolices of this Taenia, of which I 

 will speak when I consider the scolex of this ento- 

 zoon. 



The vascular network consists of a transverse 

 branch, running through the free space between the 

 four sucking discs (PI. I. fig. 7, b); from this, a 

 branch runs to and around the sucking discs, until 

 the four well-developed longitudinal vessels are seen 

 running from them in the neck (PL I. fig. 7, c, c). 

 No anastomoses are discovered between the individual 

 branches of the sucking discs ; neither is there any 

 anastomosing transverse branch on the posterior mar- 

 gin of each segment, as are found in the Tseniae. At 

 these points, however, are found small enlargements 

 of the vessels, distinguished by a kind of valvular 

 apparatus, which appears to open before the fluid 

 streaming from the head, but closes itself against that 

 running towards the head. 



In the shape of the segments also, there is a differ- 

 ence between this species and the Tsenia solium. At 

 first they have a tendency to increase in breadth, 

 being about 6 mil. broad by 1 mil. long. This 



