CLASS-BOOK OF ZOOLOGY. 157 



4:tk Order. — Prickly Worms. 



Fig. 41. 



Edible Sea-uechin. — (Echinus esculentus) 



5th Order. — Long-bodied Worms. 



Fig. 42. 



The Variegated Slug. — (Limax variegatus.) 



QUESTIONS ON SECT. XL. 



665. What does Helminthology treat of? 



666. Where are Worms found ? 



667. What use is made of this Class ? 



668. Which are the noxious animals of this Class? 



669. Into how many Orders is it divided? Name and describe 

 them. 



14 



