510 
ME.  S.  S.  BECKMAN  ON  THE  BAJOCIAN  [Nov.  1 893, 
a  The  series  just  given  is  the  most  complete  that  has  yet  been 
recognized,  but  many  of  the  beds  are  of  only  limited  horizontal 
extension.  They  occur,  however,  over  a  wider  area  than  is  usually 
supposed,  and  the  above  are  their  relative  positions  in  the  complete 
sequence. 
Beginning  the  correlation  at  the  bottom,  the  Sandy  Ferruginous 
Beds  are  to  be  exactly  identified  with  Bed  3  of  the  Marston  Road 
section.  The  Cotteswold  area  shows  clearly  enough  that  the 
greater  part  of  them  were  laid  down  after  the  Ojoalini  hemera, 
and  long  before  the  Murchisonce  hemera.  The  large  amount  of 
sediment  deposited  in  the  Cotteswolds  demonstrates  the  fact  clearly ; 
in  Dorset  and  Somerset  the  paucity  of  sediment  obscures  it. 
The  fact,  however,  remains,  and  for  determining  the  true  chrono¬ 
logical  succession  appeal  must  be  to  where  most  strata  were 
deposited.  It  will  no  doubt  be  necessary  to  recognize  the  space  of 
time  during  which  these  strata  were  deposited  as  a  hemera  with  a 
separate  name. 
The  Lower  Limestone  is  too  bare  of  fossils  to  be  correlated  with 
certainty.  It  is  usually  classed  with  the  Pea-grit  Series. 
The  Pea-grit  has  yielded  Luclwigia  Murchisonce;  and  its  brachiopod- 
fauna  also  shows  that  it  was  deposited  during  the  Murchisonce  hemera. 
The  Lower  Freestone  is  bare  of  fossils  ;  it  is  generally  classed  with 
the  Pea-grit. 
The  Oolite  Marl  and  Upper  Freestone  are  connected  by  the 
presence  of  Terebratula  fimbria  and  other  brachiopoda  ;  and  they  have 
yielded  poor  Ammonites  of  the  Lioceras  braclfordense- type.  Though 
Wright1  did  arbitrarily  separate  the  Upper  Freestone  from  the 
Oolite  Marl  to  place  the  former  in  the  Humphriesianum- zone,  and 
the  latter  in  the  Murchisonce- zone,  there  is  to  my  mind  neither  any 
reason  for  their  separation 2  nor  any  ground  to  doubt  that  they  were 
both  deposited  during  the  brcidfordensis  hemera. 
Of  the  Harford  Sands  I  can  say  nothing,  except  that  from  their 
position  there  is  just  the  chance  that  they  may  have  been  deposited 
during  the  concavi  hemera.  It  may,  however,  be  remarked  that  their 
position  below  the  Lower  Trigonia- grit  is  founded  on  the  assumption 
that  the  beds  which  lie  above  them  in  the  Northern  Cotteswolds 
are  really  contemporaneous  with  the  Lower  Trigonia-grit  of  Leck- 
hampton.  This  may,  perhaps,  be  considered  as  an  open  question. 
I  make  the  above  remark  because  the  correlation  of  the  Lower 
Trigonia- grit  has  actually  been  obscured  by  confounding  it  with 
the  Gryphite-grit.  A  Gryphcea  occurs  in  both,  but  from  observations 
recently  made  at  Leckhampton  I  should  say  that  the  Gryphcea  of 
the  Lower  Trigonia-grit  has  certainly  a  smaller  anterior  expansion 
(commonly  4  wing  ’)  than  the  form  of  the  Gryphite-grit  proper,  in 
which  the  wing  or  lobe  is  abnormally  developed.  Further,  in  the 
Gryphite-grit  proper  the  Gryphcea  is  very  abundant;  in  the  Lower 
Trigonia-grit  it  is  not  more  prevalent  than  other  lamellibranchiata. 
1  Wright,  ‘  Lias  Ammonites,’  pp.  151  et  seqq.,  Paheont.  Soc.  1879. 
2  See  Witchell,  ‘  Geology  of  Stroud,’  1882,  p.  52.  The  Upper  Freestone  is 
inducted  in  the  fimbria- stage  of  Lycett,  ‘  The  Cotteswold  Hills,’  1857,  p.  44. 
