PHYLUM PLATYHELMINTHES L'45 



>eches. Save in two exceptional cases (Temnoc&phala) vibratile 

 cilia are not known to occur on the surface in the adult condition ; 

 in some there are groups of non-motile cilia, situated on little 

 conical elevations the tactile cones. Pigment is rare in the 

 endoparasitic Digenetica, save in a few that live in the interior of 

 transparent animals, though many appear coloured variously by 



FIG. 191. Actinodactylella. b. c. bursa copulatrix ; in: brain ; c. penis ; /.intestine: or. 

 ovary; ph. pharynx; r. r. receptaculum vitelli ; t., t. testes ; r. vitelline glands; r. s. 

 vesicula seminalis. (After Haswell.) 



the internal organs shining through the translucent body wall, or 

 are stained by some fluid derived from their host. But pigment 

 is found in some of the ectoparasitic forms. 



The relationship of the Cestoda to the Trematoda is, as will be 

 subsequently shown, fairly close ; but, though there are connecting 

 forms between the two classes, the shape of the average Cestode 



