CHAPTER XVII. 

 FLAT WORMS. 



CLASSIFICATION or THE PLATYHELMINTHES (FLAT WORMS). 



Class 



Trematoda 



Family 



Fasciolklae 







Cestoda 



Paramphistomidae 



\r^\ 

 Schislocomklae 



Dibothriocephalidae 



Taeniidae 



NOTE. Two larval Taeniidae are found in man (Cysticercus cellulosae and 

 Echinococcus polymorphus) . 



Also two larval Dibothriocephalidae (Sparganum mansoni and Sparganum 

 prolifer). 



TREMATODES OR FLUKES. 



Flukes are generally leaf-like in outline, exhibiting marked variation 

 in size and shape. The largest human fluke, F. buski, is from 2 to 3 

 inches in length, while the H. heterophyes is less than 1/12 of an inch 

 in length. The most important fluke, the liver fluke, Clonorchis 

 endemicus, is flat and almost transparent, while the almost equally 

 important lung fluke, the Paragonimus westermani, is oval, almost 

 round and reddish-brown in color. With the exception of the Schis- 

 tosomidce, all flukes are hermaphrodites, and, with the exception of this 



194 



