OF THE CYSTIC ENTOZOA. 91 



genus it belongs. It has certainly more of the characters of the 

 Csenurus than Acephalocystis, although many also connect it 

 most intimately with the latter. In the meantime, however, I have 

 placed it along with Csenurus, and from its habitat called it C. 

 hepaticus. In all its more important characters, it is very- 

 similar to the C. cerebralis. 



VI. OF CYSTICERCUS. 



Cysticercus is distinguished from Csenurus by its sac having 

 only one pedicle ; it is also always contained in a cyst, which, 

 in some cases, is formed from the compressed textures of the 

 infested animal, while in others it consists of two membranes, 

 viz., one similar to that mentioned, and another, sui generis, and 

 belonging entirely to the parasite. The pedicle of the Cysticer- 

 cus, is exactly similar in its structure to that of the Csenurus, 

 with the exception of the cells, which are not arranged so regu- 

 larly. The sac is also composed of two membranes, each having 

 structures exactly similar to that of the Caenurus. 



I have divided the animals composing this genus of Entozoa 

 into two classes, in consequence of the difference of structures 

 met with in the cyst. Those species, in which the cyst is only 

 composed of one membrane, derived from the compressed tissues 

 of the infested being, have been placed near to the Acepha- 

 locysts ; and those in which the cyst consists of two membranes 

 already described, compose the other division. 



The Cysticercus cellulosce is an example of the first of these divi- 

 sions. In this animal, the cyst is very vascular, i. e. more so than 

 the surrounding textures, so that in this respect it is quite similar 

 to the analogous structure in Acephalocystis. As an example of 

 the animals belonging to this division of the genus, there is an- 

 other species which appears to be nondescript. This Cysticercus 

 was found in the Museum of the Royal College of Surgeons, but 

 unfortunately the jar was not labelled, so that I am uncertain from 

 what animal it was got. It is enclosed in a cyst formed by the 

 omentum alone ; these cysts are pedunculated, and although quite 



