ANNIYERSAR  Y  ADDRESS  OF  THE  PRESIDENT. 
Yol.  49.] 
n3 
species  of  Ammonites  characteristic  of  the  Gault  have  been  recorded 
from  the  Hunstanton  Red  Rock,  while  those  of  the  higher  horizon 
are  not  known  to  have  occurred  in  it.  As  regards  bivalves,  there 
certainly  is  in  the  Upper  Gault  a  mixture  of  Cenomanian  forms, 
and  these  seem  to  become  proportionally  more  numerous  as  the 
Norfolk  area  is  reached — a  circumstance  which  the  Authors  attribute 
to  the  effect  of  deeper  water. 
While  dealing  with  the  subject  of  the  fauna  of  the  Hunstanton 
Red  Rock,  I  should  here  take  the  opportunity  of  mentioning  that 
Mr.  Yine  has  recently  contributed  a  paper  on  the  Polyzoa  of  that 
formation.  This  Author  dealt  with  over  a  thousand  fossil  specimens, 
principally  Cephalopoda,  Monomyaria,  and  Terehratulce ,  on  most  of 
which  encrusting  forms  of  Polyzoa  were  found.  As  a  result  he 
recognized  43  species,  mostly  forms  described  by  foreign  authors, 
but  some  new.  A  few  of  these  species  have  been  noted  from  the 
Cambridge  Greensand.  The  Polyzoan  fauna  of  the  Gault  and  Chalk 
Marl,  he  says,  still  awaits  special  attention. 
The  extraordinary  diminution  in  the  thickness  of  the  Gault  and 
its  equivalents  in  North-west  Norfolk  applies  in  a  less  degree  to  all 
the  subdivisions  of  the  Lower  Chalk,  which  also  are  said  to  become 
more  calcareous  on  being  followed  northwards.  The  Totternhoe 
Stone  is  traced  through  Norfolk,  being  about  2  feet  thick  at 
Hunstanton,  and  its  existence  enables  the  limits  of  the  Chalk  Marl 
to  be  defined.  Including  the  Sponge-bed  and  the  ihoceramws-beds 
of  Hunstanton,  this  thickness  is  somewhat  under  20  feet.  The 
Grey  Chalk  also  thins  towards  the  Wash,  being  about  30  feet 
thick  at  Hunstanton. 
Mr.  William  Hill,  in  a  subsequent  paper,  carried  these  investi¬ 
gations  on  the  Lower  Beds  of  the  Upper  Cretaceous  Series  into  Lincoln¬ 
shire  and  Yorkshire,  where  the  character  of  the  strata  partakes 
somewhat  of  the  North-west  Norfolk  type,  though  their  thickness 
is  usually  somewhat  greater,  except  at  one  place  on  the  western 
escarpment  of  the  Yorkshire  Wolds.  His  discovery  of  Gault  Am¬ 
monites  tends  to  strengthen  the  view  that  the  equivalents  of  the 
Hunstanton  Red  Rock  in  the  two  more  northern  counties  are  really 
on  that  horizon.  Near  its  most  north-westerly  exposure  on  the 
Yorkshire  Wolds  the  peculiar  colour  of  the  Red  Rock  is  lost,  but 
such  characteristic  fossils  as  Inocercimus  sulcatus  and  Belemnites 
minimus  were  found  associated  with  a  conglomeratic  bed  of  slight 
thickness. 
The  base  of  the  Chalk  Marl  throughout  Lincolnshire  continues  to 
be  marked  by  a  bed  of  compact  limestone,  which  the  Author  regards 
