MONOGRAPH 



ON THE 



BRITISH FOSSIL 



ECHINODBRMATA 



THE CRETACEOUS FORMATIONS. 



THOMAS WRIGHT, M.D., F.R.S. Edin., F.G.S. ^ '"" ^ 



CORKESVONDING MEMBER OF THE KOYAL SOCIETY OF SCIENCES OF LIEGE, THE SOCTETV OF 



NATURAL SCIENCES OP NEUFCIIATEL, AND SENIOR SURGEON TO 



THE CHELTENHAM HOSPITAL. 



VOLUME FIRST. 



PART FOURTH. 

 ON THE DIADEMADYE AND SALENIHi^.. 



Pages 137—160 ; Plates XXX— XXXIX. 



LONDON: 



PRINTED FOR THE PAL^ONTOGRAPHICAL SOCIETY. 



1871. 



