A 



TEEATISE ON ZOOLOGY 



EDITED BY 



E. EAY LANKESTER 



M.A., LL.D., F.R.S. 



HONORARY FELLOW OF EXETER COLLEGE, OXFORD ; CORRESPONDENT OF THE INSTITUTE 



OF FRANCE ; DIRECTOR OF THE NATURAL HISTORY DEPARTMENTS 



OF THE BRITISH MUSEUM 



PART IV 



THE PLATYHELMIA, MESOZOA, AND 

 NEMERTINI 



BY 



W. BLAXLAND BENHAM, D.Sc.(Lond.), M.A.(Oxon.) 



PROFESSOR OF BIOLOGY IN THE UNIVERSITY OF OTAGO, NEW ZEALAND ; FORMERLY ALDRICHIAN 

 DEMONSTRATOR OF ANATOMY IN THE UNIVERSITY OF OXFORD 



LONDON 



ADAM & CHAELES BLACK 

 1901 



