IIO  PROCEEDINGS  OP  THE  GEOLOGICAL  SOCIETY.  [May  1893, 
that  nourished  a  numerous  Molluscan  fauna,  and  in  which  Fishes 
and  great  marine  Saurians  abounded,  and  he  seemed  to  think  that 
there  had  been  no  previous  discovery  of  phosphatic  beds  analogous 
to  those  of  Ciply. 
However  this  may  be,  Mr.  Strahan’s  discovery  at  Taplow,  though 
not  of  much  economic  importance  in  consequence  of  the  limited 
extent  of  the  deposit,  is  strictly  analogous  from  a  chemico-geological 
point  of  view.  Here  also  we  have  the  brown  phosphatic  grains  in 
a  chalky  matrix,  and  it  is  interesting  to  learn  that  these  grains 
are  almost  entirely  of  organic  origin,  Foraminifera  and  shell-prisms 
forming  the  bulk  of  them.  The  tests,  as  well  as  the  contents,  of  the 
Foraminifera  seem  to  have  been  phosphatized,  the  phosphate  appear¬ 
ing  as  a  translucent  film  in  the  former  case,  and  as  an  opaque  mass  in 
the  latter.  In  the  case  of  the  prisms  of  Molluscan  shells  the  whole 
of  the  phosphate  appears  in  the  opaque  form.  Fragments  of  fish¬ 
bone  also  are  observed  to  occur  in  the  granular  portion,  and  such. 
Dr.  Hinde  remarked,  are  also  present  in  the  Ciply  material,  but 
their  osseous  nature  had  not  previously  been  recognized.  As  bearing 
on  the  question  of  the  nitrogenized  organic  substance  suggested  by 
M.  Cornet,  the  brown  colour  of  this  rock  at  Taplow  is  attributed  to 
a  substance  very  near  to,  if  not  identical  with,  humic  acid,  but 
stated  to  contain  between  3  and  4  per  cent,  of  nitrogen.  Every¬ 
thing  seems  to  point  to  the  remains  of  Fishes  as  having  been  the 
principal  source  of  the  phosphate,  although  other  organisms  may  have 
contributed  thereto.  In  the  very  extensive  replacement  of  carbonate 
of  lime  by  phosphate  of  lime  which  has  taken  place,  it  is  possible 
that  organic  acids,  remains  of  which  are  still  traceable  in  these  rocks, 
may  have  played  an  important  part. 
Quitting  the  horizons  of  the  Higher  Chalk  we  will  now  proceed 
to  consider  the  lower  beds  of  the  Upper  Cretaceous,  more  especially 
in  the  East  of  England,  where  these  beds  have  undergone  a  most 
important  revision,  principally  at  the  hands  of  Messrs.  Jukes-Browne 
and  AUilliam  Hill.  It  must  be  premised  that  these  Authors  had 
already  laid  the  foundation  for  their  subsequent  work  by  their 
joint  contribution  on  the  4  Melbourn  Hock  and  the  zone  of  Belemni- 
tella  plena  from  Cambridge  to  the  Chiltern  Hills.’  That  paper  lies 
beyond  the  limits  of  the  present  Address,  though  it  may  be  as  well 
to  remind  you  that  the  Belemnitella- marls  were  therein  regarded  as 
forming  the  summit  of  the  Lower  Chalk,  while  the  Melbourn  Hock, 
which  rests  upon  these  marls,  is  taken  to  be  the  base  of  the  Middle 
Chalk,  commencing  with  the  zone  of  Ehynchonella  Cuvieri „ 
