PHYLUM PLATYHELMINTHES 



J23 



pharyiw (ph.), which is highly mobile, and is capable of being 

 thrust out as a proboscis through the mouth, beyond which it 



FKI. 171. Planar ia. Digestive and excre- 

 tory systems, ex. openings of excretory 

 system ; int. intestine ; mo. mouth ; 

 n. ph. opening of pharynx. (After Jijima 

 and Hatschek.) 



FIG. 172. Planaria. Nervous system- 

 /'/. brain ; tyt eye ; /. n<:. longitu- 

 dinal nerve ; pit. pharynx. (After 

 Jijima and Hatschek.) 



may then be extended to a relatively considerable -distance, 

 When retracted it lies within an enclosing muscular sheath. The 



