ZOOLOGICAL AETICLES 



CONTRIBUTED TO THE "ENCYCLOPEDIA BRITANNICA" 



E. EAY LAJ^KESTEE, M.A., LL.D., F.E.S. 



DEPTTTT LINACKB PKOFESSOK IN THE TTNIVEKSITY OF OXFOED, AND BON. FELLOW OF EXETER COLLEGE 



PRESIDENT OF THE MABINB BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM ; 



HON. MEMBER OF THE CAMBRIDGE PHILOSOPHICAL SOCIETY; 



CORRESPONDING MEMBER OF THE ACADEMY OF SCIENCES OF PHILADELPHIA. 



TO WHICH ABE ADDED KINDBED ABTIOLES BY 



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



PROFESSOR OF GEOLOGY IN TRINITY COLLEGE, DUBLIN. 



LUDWIG VON GRAFF, Ph.D. 



PROFESSOR OF ZOOLOGY IN THE UNIVERSITY OF GKAZ, AUSTRIA. 



A. A. W. HUBRECHT, Ph.D., LL.D. 



PROFESSOR OF ZOOLOGY IN THE UNIVERSITY OP UTRECHT. 



A. G. BOURNE, D.Sc. 



PROFESSOR OF BIOLOGY IN THE PRESIDENCY COLLEGE, MADRAS. 



W. A. HERDM.AN, D.Sc. 



PROFESSOR OF NATURAL HISTORY IN THE UNIVERSITY COLLEGE, LIVERPOOL. 



EDINBURGH: ADAM & CHARLES BLACK 

 NEW YORK: CHARLES SCRIBNER'S SONS 



MDCCCXCI 

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UNIV[-ke(i Y 



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