Yol.  49.] 
OF  THE  SHERBORHE  DISTRICT. 
515 
quotes  for  this  Bed  4  (op.  cit.  pp.  532,  533)  agree  with  those  from  the 
lower  part  of  the  Sandford  Lane  ‘ Fossil  Bed’;  he  says  nothing 
about  these  species  occurring  any  higher,  only  patella  is  mentioned. 
In  the  main,  then,  the  agreement  with  the  Sandford  Lane  ‘Fossil 
Bed’  in  such  a  particular  is  rather  remarkable,  because,  though  about 
30  feet  of  the  strata  at  -Gingen  are  represented  by  20  inches  at 
Sandford  Lane,  Ammonites  of  the  patella- type  occur  at  the  top, 
and  those  of  the  Jissiloba tus-type  at  the  bottom. 
His  location  of  A.  Sauzei  above  patella  seems  at  first  to  conflict 
with  my  statements  about  its  position  ;  but  it  is  probably  explicable 
by  a  somewhat  wider  interpretation  of  ‘  A.  Sauzei  ’  on  my  part. 
In  the  time  of  the  concavi  or  discitce  hemera  there  were  species 
of  the  Sauzei- type ;  and  the  series  continued  nearly  until  the  time 
of  the  Humphriesiani  hemera.  Which  of  the  various  forms  will 
eventually  be  found  to  be  the  true  type  I  have  not  yet  had  time  to 
fully  investigate. 
Waageu  figures  A.  dis cites  as  a  species  of  the  Soiverbyi-zone,  but 
not  from  Gingen.  This,  however,  suggests  that  in  certain  places 
his  Sowerbyi- zone  strata  included  some  which  were  deposited  during 
the  discitce  hemera.  It  is  not  difficult  to  see,  by  looking  at  the 
Sandford  Lane  section,  that  one  or  two  of  the  beds  below  the 
‘  Eossil  Bed  ’  might  be  the  equivalent  of  the  lower  strata  which 
Waagen  included  as  Sowerbyi- zone.  What,  however,  it  is  possible 
to  say  with  very  great  precision  is  this  :  that  Waagen’s  Bed  4  at 
Gingen,  and  the  lower  part  of  the  Sandford  Lane  4  Fossil  Bed,’  were, 
by  the  evidence  of  the  Ammonites,  deposited  at  exactly  the  same 
time.  The  use  of  the  name  Sowerbyi  to  designate  the  strata  of  this 
hemera  cannot,  however,  be  allowed.  The  species  which  Sowerby 
figured  has  been  incorrectly  identified,  and  it  is  moreover  a  species 
which  belongs  to  a  somewhat  later  date  ;  at  least  at  Hundry  it  is 
found  associated  with  4  Stephanoceras’  Sauzei.  Had  it  been  a 
species  of  the  hemera  of  Witchellia  sp.,  it  would  have  been  only 
just  to  Waagen  to  continue  its  use  for  that  hemera. 
(b)  Correlation  with  Normandy . — A  very  interesting  communi¬ 
cation  was  made  by  Munier-Chalmas  to  the  Geological  Society 
of  France  on  Dec.  5th,  1892.1  He  has  evidently  studied  the 
Ammonite-horizons  with  very  considerable  care,  and  it  is  advisable 
to  note  his  results,  especially  as  they  were  not  jmblished  till  some 
five  months  after  my  investigations  in  Dorset  were  finished.. 
I.  On  p.  164  he  says  that  the  various  strata  ( les  differentes  assises ) 
of  Ludwigia  Murcliisonce  can  be  divided  into  three  zones : — 
A.  “The  lower  zone  ....  characterized  by  the  typical  Ludwigia 
Murchisonced  also  by  “  Ludwigia  Murcliisonce,  var.  Haugi , 
Douv.  ;  Ludw.  Murch.  var.  obtusa,  Quenst.” ;  and  “  Tmetoceras 
scissum  (Ben.)”  is  present. 
B.  The  middle  zone  with  “  Ludwigia  Murcliisonce ,  var.  Bay  lei  ; 
a  Hammatoceras  near  to  H.  Sieboldi ;  and  two  species  of 
1  c  L’Etude  preliminaire  des  Terrains  jurassiques  de  Normandie.’  Compte- 
rendu  sommaire  des  Seances,  Soc.  geol.  France,  No.  14,  1892. 
