Yol.  49.]  ANNIVERSARY  ADDRESS  OF  THE  PRESIDENT.  127 
latter  is  characteristically  represented  in  the  shell-bed  at  the  base 
of  the  underlying  series.  J ust  the  same  difficulty  occurs  at  Crickley 
Hill,  near  Cheltenham,  where  the  equivalents  of  the  Lower  Lime¬ 
stone  are  almost  devoid  of  fossils,1  while  the  33  feet  of  Pea-grit 
which  succeeds  contains  perhaps  the  richest  and  most  varied  fauna, 
including  a  coral-bed,  to  be  found  anywhere  in  the  Inferior  Oolite 
of  the  Cotteswolds.  Reverting  to  the  Stroud  and  Yailsworth 
district,  the  series  for  some  distance  above  the  typical  Pea-grit  of 
that  region  contains  here  and  there  aggregations  of  brown  pisolites 
— Girvanella  pisolitica  of  Mr.  Wethered — and  since  the  fauna  is 
practically  the  same  as  that  of  the  typical  bed,  the  whole  may  be 
regarded  as  one  local  series.  This  cannot,  however,  apply,  as 
intimated  by  Mr.  Wethered,  to  the  Lower  Limestone  of  Mitchell. 
With  reference  to  the  divisions  between  the  Murchisonce-  and 
opalinus-zomes,  Mr.  Buckman  has  lately  found  at  Symondsbury  Hill 
Ammonites  (Ludwigia)  Murchisonce  and  Am.  ( Lioceras )  opcdinus 
in  the  same  bed.  This  circumstance,  he  says,  renders  it  difficult  to 
draw  a  line  of  demarcation  between  Lias  and  Oolite  at  the  top  of 
the  opcdinus- zone.  Such  a  rare  and  accidental  rencontre  of  two 
zonal  Ammonites  would  scarcely,  if  considered  alone,  substantiate 
this  view,  but  in  many  respects  it  is  not  easy  to  effect  a  separation 
between  these  two  zones.  Since  there  has  been  no  serious  attempt, 
so  far  as  I  am  aware,  to  draw  a  line  of  demarcation  between  Lias 
and  Oolite  at  the  top  of  the  opcdinus- zone,  the  question  of  defining 
the  upward  limit  of  that  zone  is  one  of  minor  importance. 
But  if  Mr.  Witchell  has  been  able  to  supply  a  correction  of  some 
importance  to  the  previously  accepted  reading  of  the  lowest  beds  of 
the  Inferior  Oolite  within  a  limited  area,  a  more  important  piece  of 
work  has  been  effected  by  Mr.  Buckman.  His  paper  on  the 
‘  Cotteswold,  Midford,  and  Yeovil  Sands  and  on  the  Division 
between  Lias  and  Oolite  ’  must  be  regarded  from  a  wider  stand¬ 
point,  as  involving  more  extensive  issues.  For  some  time  past  there 
has  been  considerable  doubt  as  to  whether  the  Yeovil  Sands  and  the 
Cotteswold  Sands,  although  they  both  underlie  the  limestones  of  the 
Inferior  Oolite,  are  really  on  the  same  horizon.  This  was  a 
difficulty  which  I  felt  when  engaged  in  writing  the  Introduction 
to  the  4  Inferior  Oolite  Gasteropoda/  and  I  then  came  to  the  con¬ 
clusion  that  probably  they  were  not  on  precisely  the  same  horizon. 
1  Ttygrnatis  xmos,  Hucl].,  occurs  sparingly  in  the  shell- bed  below  the  Lower 
Limestone  on  Crickley  Hill,  and  this  position  justifies  us  in  regarding  it  as 
the  oldest  species  of  Nerincea  hitherto  discovered  in  Britain. 
