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MR.  S.  S.  BUCEMAH  OUT  THE  BAJ0CIAN 
[Nov.  1893, 
beds  is,  of  course,  governed  by  the  correlation  of  the  Upper  Trigonia- 
grit ;  but  its  exact  correlation  is  very  uncertain.  This  is  a  matter 
which  requires  to  be  worked  out  by  one  of  two  methods,  the  geolo¬ 
gical  and  the  palaeontological,  or  by  both  combined.1 
Table  III.  (facing  this  page)  summarizes  the  conclusions  arrived 
at  in  regard  to  the  correlation  of  certain  localities  of  the  Sherborne 
district  with  themselves,  with  Dundry,  and  with  Leckhampton.  As 
the  diagrams  are  drawn  to  scale,  the  fluctuations  in  accumulation 
of  sediment  may  be  noted. 
2.  Foreign  Correlation. 
(a)  Correlation  with  Wurttemberg .- — The  correlation  of  the  strata 
deposited  during  the  different  hemerte  in  Dorset  with  the  zonal 
divisions  of  Oppel,  and  with  the  a,  [3,  y  arrangement  of  Quenstedt, 
is  too  obvious  to  need  discussion  here  ;  all  that  requires  to  be  noticed 
is  the  remarkable  absence  from  Quenstedt’s  works  of  any  Ammonites 
which  lived  in  the  concavi  hemera ;  and,  in  fact,  that  they  are  new 
to  science  generally  is  fully  attested  by  the  plates  in  my  Monograph.2 
What  is  necessary  for  me  to  do,  however,  is  to  point  out  how  the 
Dorset  strata  agree  with  Waagen’s  1  Sowerbyi-zone.’ 
It  is  evident,  from  what  Waagen  says  in  reference  to  the  Dorset 
and  Somerset  strata,3  that  he  regarded  what  we  now  call  ‘  concavum- 
zone  ’  as  either  equivalent  to  or  part  of  his  4  Sowerbyi-zone.9  From 
the  date  when  his  work  was  published,  and  from  what  I  know  of 
the  Sandford  Lane  Quarry  and  its  working,  I  should  doubt  whether 
he  saw  any  of  the  species  of  the  Sandford  Lane  ‘Fossil  Bed/' 
However,  Section  IX.  (p.  492)  shows  that  this  bed  lies  well  above 
the  strata  which  yield  Lioceras  concavum — that  it  is  separated  there¬ 
from,  in  fact,  by  strata  which  yield  Hyperlioceras  ;  yet  it  is  this 
‘Fossil  Bed’  which  alone  yields  Ammonites  of  the  same  species 
as  Waagen  figures  in  his  work. 
Closer  examination,  too,  shows  how  exactly  this  ‘Fossil  Bed’ 
corresponds  with  the  strata  which  Waagen  designates  Sauzei- 
and  Sowerbyi-zones.  He  gives  at  Gingen  4 : — 
1.  Yellow  clay,  with  JBelemnites  giganteus. 
2.  Sandy  limestone,  Ammonites  Sauzei,  A.  polyschides,  about  4  feet. 
3.  Sandy  clay,  A.  patella ,  20  feet. 
4.  Sandy  clay,  A.  Sowerbyi,  2-3  feet. 
It  is  noticeable  that  he  places  A.  patella  above  A.  Sowerbyi , 
although  he  states  that  he  found  patella  with  Sowerbyi,  jissilobatus, 
etc.,  in  Bed  4.  Excepting  patella,  the  series  of  Ammonites  which  he 
]  Owing  to  the  scarcity  of  Ammonites  in  the  Cotteswolds,  fragments  become 
of  value,  provided  they  are  obtained  in  situ  and  are  authenticated  by  a  good 
label,  stating  the  locality  and  the  number  of  feet  above  a  certain  datum-line, 
say  ‘  base  of  Upper  Trigonia- grit/  ‘  top  of  Upper  Freestone/  etc.,  as  may  be 
most  convenient. 
2  Palseontographical  Society,  1887-1892,  et  seq. 
3  Ueber  die  ‘Zoned.  Amm.  Sowerbyi .’  Geogn.-pal.  Beitrage,  Bd.  i.  (1867) 
Heft  3,  p.  573  et  seq. 
4  Ibid.  p.  531. 
