CLASS ANNELIDA. 



25 



or appendages of any kind, and locomotion is entirely- 

 effected in the manner just alluded to. 



,.- h 



as 



kL\ 



A 



B 



Fig. II. — A, Diagram of the Leech, showing the nervous system, and the ten 

 eyes placed on the top of the head. B, The leech dissected to show 

 the ahmentary canal (j), and the so-called "respiratory sacs" (r r); 

 as Anterior sucker ; ps Hinder sucker ; n n Nervous system ; h Head, 

 carrying the eye-spots. 



The mouth opens at the bottom of the front sucker, and 

 is provided with three crescentic jaws (fig. 10, b and c), 



