ZOOLOGICAL ARTICLES 



CONTRIBUTED TO THE "ENCYCLOPAEDIA BRITANNICA" 



BY 



E. RAY LANKESTER, M.A., LL.D., F.R.S. 



DEPUTY LINACRE PROFESSOR IN THE UNIVERSITY OF OXFORD, AND HOX. FELLOW OF EXETER COLLEGE 

 PRESIDENT OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM ; 



HON. MEMBER OF THE CAMBRIDGE PHILOSOPHICAL SOCIETY; 

 CORRESPONDING MEMBER OJ TH.E ^ADEMY OF SCIENCES OF PHILADELPHIA. 



TO WHICH ARE ADDED KINDRED ARTICLES BY 



W. JOHNSON SOLLAS, LL.D., F.R.S. 



PROFESSOR OP GEOLOGY IX TRINITY COLLEGE, DUBLIN. 



LUDWIG VON GRAFF, PH.D. 



I'ROFESSOE OF ZOOLOGY IX HIE UNIVERSITY OF GRAZ, AUSTKU. 



A. A. W. HUBRECHT, PH.D., LL.D. 



PKOFESSOK OF ZOOLOGY IN THE UNIVERSITY OF CTKKCBT. 



A. G. BOURNE, D.Sc. 



FKOFESSOB OF BIOLOGY IX THE PRESIDENCY COLLEGE, MADRAS. 



W. A. HERDMAN, D.Sc. 



PBOFESSOE OF SATCRAL HISTORY IS THE US1VEKSITY COLLEGE, LIVERPOOL. 



EDINBURGH: ADAM & CHARLES BLACK 

 NEW YORK: CHARLES SCRIBNER'S SONS 



MDCCCXCI 



