Harmer,S.F,ed. <br/><br/>
The Cambridge natural history , Vol. II:  Flatworms and Mesozoa;Nemertines,Rotifers,Thread-Worms,Sagitta,Gephyrea and Phoronis;Earthworms and Leeches;Polychaet Worms and Polyzoa/ 
edited by S.F.Harmer and A.E.Shipley 
 - England:  Wheldon &Wesley,Ltd.,  1970. 
 - 560p. 
<br/><br/><label>Dewey Class. No.: </label>590  / HAR/C V.2